IronMick’s Complete Guide to Troubleshooting Ironhead Electrical Problems

This article was originally posted on by IronMick in response to one community member’s effort to discover why his Ironhead battery was draining. IronMick’s “guide” works great for the Ironhead, but it can also be used to troubleshoot other bikes’ electrical systems.

Follow this procedure carefully. Do not leave out any steps …

IronHead Charging System Checkout

You need a multimeter. The digital ones are best and can be had for less than $10.00. A voltmeter is a multimeter set to measure DC volts. An ammeter is a multimeter set to read DC current in amps. The ohmmeter section of the multimeter will test for continuity. Continuity means that current may flow between the two points.

I find alligator clip probes are much more convenient than pointer probes. Occasionally a pointer probe is better so i have a set of each.

When using a Multimeter, if the object fails a test, repeat the test ensuring that you have good connections with the meter probes, especially to a good ground.

1. Fully charge battery.

It is not good enough to put it on a charger overnight and assume it is fully charged. Some batteries will take 24 hours to fully charge. The way to know for sure is to do a specific gravity test [for liquid filled batteries], or to use an automatic battery charger.

I have heard that you should never use a battery charger greater than 2 amps for any motorcycle; that it is best to use between .75 and 1.5 amps. Best are the automatic chargers such as Battery Minder or Battery Tender.

2A. Cell test battery [not for maintenance-free batteries].

Remove caps from battery cells. Keep the red voltmeter lead on a terminal and insert the black lead progressively into each cell, far enough that it contacts the plates. You should get readings of 2, 4, 6, 8, 10 and 12 volts. If one cell does not contribute its proper 2 volts then that cell is dead and the battery is no good.

2B. Load test battery.

It is said that, with electronic ignition, you should never crank the engine without grounded plugs attached to the wires. For this test you should install an extra set of plugs into the wires and set them onto the top cylinder head fins.

Disconnect both spark plugs. Attach voltmeter leads to the battery terminals. Crank the engine for 10 seconds [no more!]. Observe the meter WHILE cranking. If it goes below 10 volts then the battery is no good. Alternatively you can buy an expensive battery load tester.

Bring the battery up to full charge again before proceeding.

3A. Current Drain Test #1

Disconnect the battery -ve cable from the battery. Connect the ammeter between battery -ve post and the battery cable. It should read .003 amps or less.

3B. Current Drain Test #2

Disconnect the +ve terminal from the battery. Connect an automotive test light between the battery and the cable. If light comes on there is a current draw.

Note: To determine which circuit is faulty disconnect the circuit breakers or remove the fuses one at a time. When the light goes out you know which circuit is the problem.

3C. Battery Cables Test

With voltmeter connected to battery terminals check voltage while cranking. Then with voltmeter on battery cables check voltage while cranking. If voltage drop due to cranking [should not go below 10 volts] is different cables may be bad or there may be corrosion.

Here is another very simple non complex test you can do if you suspect that something is draining your battery when the key is off. This applies to bikes that have no digital instrumentation (like ironheads). Unhook your negative battery terminal. Touch the wire back to the negative battery terminal, there should be no spark when you do. If it arks and sparks (like a downed hydro pole in a rain storm in a horror movie) then something is drawing power when it shouldn’t be.

4. Charging System Test

Measure the battery voltage with the bike not running. It should be at least 12.x; preferably it will be 13.x.

Measure the voltage with the bike idling at about 2000 to 3000 RPM. It should be at least 1.0 volts higher than the not-running reading, otherwise the charging system is not charging the battery. It should be at least 13.x, preferably 14.x.

5. Regulator Test

Disconnect the regulator. Connect your ohmmeter to the orange and tan wires. Note the reading. Reverse the connections. Note the reading. One reading should show continuity, the other should show no continuity. If the regulator does not pass this test it is no good. This is the circuit that prevents the reg from draining the batt when the bike sits overnight.

This test only tests one circuit in the regulator, so even if it passes this test it may still be no good. There are other tests of the regulator that require specialized equipment. These tests are in the factory and Clymer manuals. I recommend taking both the reg and the gen to an automotive electric repair shop for testing if needed. Note: these shops usually want to test both parts together.

6. Generator Test #1: Residual Magnetism

Disconnect both the A and F terminal wires. Connect the +ve voltmeter lead to the A and the -ve lead to ground. Run the engine at about 2000 RPM. The meter should read at least 2.0 volts. If the voltage is low polarize the generator and repeat the test. If the generator fails this test it must be disassembled for repair.

7. Generator Test #2: Maximum Output

Remove both the A and F terminal wires. Connect the +ve voltmeter lead to the A and the -ve lead to ground. Run the engine at about 2000 RPM. MOMENTARILY [not longer than 10 seconds] connect a jumper lead from ground to F and read the meter. The meter should read 25 to 30 volts DC. If the generator fails this test it must be disassembled for repair.

8. Here’s a good way to bench test your generator:

1. connect a jumper from the “+” battery post to the “A” armature terminal on the gen.
2. Connect a jumper from the “-” battery post to the “F” field terminal of the gen.
3. Now take a third jumper from the “-” battery post and touch it to the case of the gen.

If all is well the generator will run like an electric motor. With the gen gear pointing away from you the rotation is clockwise.

Don’t try this with the generator on the bike.

9. Polarizing the Generator

With the generator fully installed in the bike, all connections made, ignition off; connect one end of a jumper wire to the gen A, and momentarily touch the other end to the battery +ve terminal.

Usually [but not always they say], you will get a spark at the battery terminal and a light clunk sound from the gen.

10. Polarizing the Generator – The Complete Story

1. with the gen on the bench
[i] jumper the gen A to batt +ve
[ii] momentarily jumper from gen F to batt -ve

Note: This can be done the other way around,
[i] jumper gen F to the -ve batt
[ii] momentarily jumper gen A to batt +ve

2. with the gen on the bike, wires not connected
[i] jumper from gen F to a good ground
[ii] momentarily jumper from gen A to batt +ve

Note: This technique is preferred over #3 because the good ground is better than relying on grounding the F thru the reg.
Note: As with #1 this can be done the other way around.

3. with the gen on the bike, all wires connected
[i] momentarily jumper gen A to batt +ve

Note: This is technically the same as techniques #1 and #2 as the F is grounded thru the reg.

4. For bikes with a mechanical reg [1959 to 1977]

Momentarily jumper between BAT and GEN on the reg.

Note: this is technically the same as all of the other techniques as BAT is connected to batt +ve and GEN is connected to gen A.

5. For bikes with a Cycle Electric Generator/Regulator

On the Cycle Electric DGV-5000 generators you have to remove the brush cover and touch a wire from the positive terminal of the battery to the positive brush lead of the generator to polarize it. You can’t polarize the generator from the external terminals. (One of the terminals is the battery terminal, and the other has an internal diode.)
You have to try pretty hard to reverse the polarity on those generators and they rarely need to be polarized.

For clarification: Cycle Electric does have a voltage regulator (the CE-540) which looks very similar. It will bolt up to a standard Model 65A generator and has external leads which connect externally between the regulator and the generator.
The CE-500 bolts to a Cycle Electric DGV-5000 generator and the regulator is internally wired to the generator.
– With the CE-540 setup the generator can be polarized by running a lead from the battery + to the “A” terminal.
– With the CE-500 you need to polarize the generator at the positive brush lead.

11. Generator Brushes Assembly: Dismantle, Cleaning, Repair

1. The brushes holder and related parts can be dismantled without removing the gen from the bike. This is useful because, in my [limited] experience, if the gen light is coming on then one or both of the brushes is probably sticking. This can be easy to fix.

I am writing this from memory, not while doing it. I think i have the removal process right.

Remove gen end cap. Remove the bracket and brush cover strap. Remove the commutator end cover. There are 3 screws visible. Two just hold the brushes to the brush holder; these do not need to be removed. The third screw attaches a wire from inside the gen to the brush assembly. Remove this screw. Now the brush assembly can be removed.

Usually it is quite dirty in there so at this point i use a spray can of electrical contacts cleaner to clean up the mess.

The brushes will spring out of the brush holder. They must be each longer than 1/2 inch else replace both. Reinstall each temporarily and work them between thumb and finger to see if there is any binding.

To re-install brushes in holder use long twist ties from the kitchen. Pick out the twist ties after the holder is re-installed.

2. To remove the gen from the bike: Disconnect the wires from the A and F terminals; remove the two bolts from the gearcase side; raise the inner end toward the 11:00 o’clock position, lower the outer end toward the 5:00 o’clock position, and remove carefully.

For the rest you really need a manual. The FM is very good. It is usually not necessary to remove the gen drive gear – this requires a gear puller to remove. The rest of the gen dismantles quite easily.

Once opened up you can do more cleaning and inspection; again using the spray can electrical contacts cleaner.

The FM contains a number of tests that you can easily do once it is opened up: field coil test, shorted or open field test, grounded armature test, and open armature test.

The shorted armature test requires special equipment which a shop would have [a growler]. Doing actual repair may require special equipment such as a lathe, and perhaps experienced hands.


Poll: King or Porkster Tank for the Ironhead

After spending a few hours trying to strip cemented Plasti Dip from the peanut tank I had on the Ironhead, and getting only a third of the way done, I decided that this particular 1977 Harley-Davidson Sportster XLH1000 deserved a new gas tank.

I wanted a little bit more capacity than the standard tank (which has a range of about ninety miles), so I bid on a new Custom Chrome 3.2 gallon king tank, setting my max bid well under retail, but high enough that I had a chance of winning.

I also saw a used porkster tank, with about 3.5 gallon capacity and no dents or rust inside the tank. These Porksters are selling for a couple of hundred dollars, so I didn’t think my low-ball bid had a chance.

I won both.

Fortunately, I came in lower on both tanks combined than it would have cost me to buy the king tank outright, so I’m not too upset.

The problem I have now is I can’t decide which tank to put on the bike. So, I’ll leave it up to you. Let me know in the comments below which tank you think I should put on this Ironhead: porkster (the stretched tank with dual gas caps) or the king tank (the oversized peanut tank commonly found on Sportsters).



Technological Terror

After running the ’77 Ironhead (aka Imperial Entanglement) for the past few months with a “temporary” Plasti Dip paint job, I decided it was time to give it a more permanent paint job.

My plan is to show a lot of bare metal with black primer accents, and seal it under a nice layer of clear coat.

Shortly after I did the original Plasti Dip paint job, I managed to spill a few drops of gasoline on the tank. The result wasn’t pleasant.

I peaked off the ruined Plasti Dip and reapplied another layer over the original purple paint. Because a little gas spillage is inevitable, this time around finished the Plasti Dip paint job with an acrylic clear coat.

The result was beautiful, and it almost looked like a real paint job.

Unfortunately, that clear coat / Plasti Dip came back to haunt me when started the process of repainting the tank.

Apparently, clear-coated Plasti Dip is highly resistant to paint strippers, including Aircraft Stripper. Additionally, the process seems to create an ultra-hard shell (after a few minutes of goopy nastiness) that can only be removed with a lot of elbow grease and power tools.



Thirty-Six Years of Road Grime

I try to keep my bikes clean, and when I’m washing them, I pay special attention to those hard-to-reach places. But some places are totally unreachable, and dirt and grime accumulate, layer after layer, year after year.

On my 1977 Harley-Davidson Sportster XLH1000 “Ironhead,” one of these impossible-to-reach grime collectors is the inside of the primary chain guard. Normally I wouldn’t even think about the grime collecting there, but when I was freeing up a sticking rear brake line (which required some disassembly of the right primary cover), I happened to reach my finger around the back of the cover while trying to free the brake line, and my index fingertip sunk to the first knuckle in gritty, greasy grime.

I pulled off the cover to inspect it, and I saw that it was so deep, the chain was actually carving a groove through it. As I scraped away at it, the harder, deeper layers resisted until they gave away in big chunks. That greasy mess was slopped onto the primary cover sometime in the Carter administration.

It took about half an hour to clear out the grime, and while I was concerned the metal would be pitted with corrosion, the exposed metal actually gave off a nice dull shine.

Removing the primary cover wasn’t that big if a task, so I’m adding “Clean muck out of primary cover” to my 10,000 mile service checklist.





VIDEO: Setting Points on the Ironhead Sportster

ShadowDog500 posted a great video on adjusting points on the Ironhead Sportster. Messing with ignition systems on older bikes (or news ones) always sounds a bit intimidating to me, but ShadowDog500’s tutorial clears up a lot of the mystery and provides a concise explanation of how to get the job done, including dozens of tips and tricks you won’t find spelled out in your shop manual.

Is Plasti Dip Gasoline Resistant?

No. Performix Plasti Dip is absolutely NOT gasoline resistant. At all.

The gas tank on my 1977 Ironhead Sportster can attest to this. Granted, my original Plasti Dip paint job wasn’t all that great, and it is definitely my fault for not screwing on the gas cap tight enough.



As you can see from the photo, the gasoline that spilled out of the tank ate up the Plasti Dip. It was an instantaneous chemical reaction: there was no time to clean off the tank before the gas turned the texture of the Plasti Dip into something reminiscent of a char grilled lizard.

I don’t want to repaint the whole tank, so I plan to follow one of the tutorials I’ve seen on YouTube showing how to repair Plasti Dip. I’ll post the results.

Imperial Entanglement


ManualsWhen I saw this 1977 Ironhead Sportster on Craigslist, I just couldn’t resist. Something about the black and white paint job made me think of Stormtroopers (from Star Wars, not Nazi Germany). It’s definitely been a technological terror (which apparently is common with AMF Harley-Davidsons), and I’ve already had fun troubleshooting electrical issues, whining clutch bearings, a rusted-out tachometer cables, a leaky brake master cylinder, and fouled plugs galore.

At one point, I was afraid I’d been sold a thirty-six year-old hunk of junk. And we all know where fear leads, right?

imageWell, I tried to go all Jedi-zen, and accept that this bike is just high maintenance, but Master Yoda wasn’t around to guide me. So yes, when my front cylinder stopped firing, my fear quickly lead to anger, and when my turn signals stopped working DURING the Virginia Motorcycle Safety Inspection, my anger lead to hate, and when my battery died and I had to roll start the bike back from the inspection station, rather than just give up and cry, I embraced the Darkside.

Yes. Yessssss.

I am know bending this Ironhead to my will, forcing all pistons to fire, blasting electrical connections clean, and forcing the battery to charge under the watchful gaze of my minion, Admiral Battery Tender.

It may take this old Ironhead twelve parsecs to make the Kessel Run, but I’ve shown it who is the Learner and who is the Master!


77 Ironhead Survey: Turtle Tank or Peanut Tank

The previous owner of the ’77 Ironhead replaced the stock peanut tank with a hard-to-find turtle tank common on Sportsters of the late 1960’s. The turtle tank certainly looks good when the bike is rigged like a cafe racer, but I’m leaning more towards a mild chopper or a bobber. With the nine inch risers I put on the bike (so I didn’t have to lean fat gut over the tankntomreach the drag bars), the turtle tank just doesn’t look right.

imageI like the extra fuel capacity, and the unique look combined with the rarity of the turtle tank are both big plusses, but I just don’t think it fits the “theme” of the bike.

I’ve reprinted the tank with black plastidip to keep the rust off the few areas where the original paint is chipping. If I keep it, I’ll give it a real paint job.

The previous owner did give me two peanut tanks with the bike, so I don’t have to come out of pocket for a new tank. I’ve actually had several offers on the turtle tank already, so I’m getting a bit incentivized to Del it.

Let me know your feedback (or if you want to buy one of the tanks) in the comments.

Custom Chrome Forward Controls: FAIL

Last week I picked up a set of Custom Chrome forward controls for the ’77 Ironhead. I bought the on eBay from a reputable dealer for about $200, and while I didn’t expect them to be the fanciest forward controls, I did expect them to be good basic controls.

The forward controls I bought we’re made for ’78 and up Ironheads, but looking at the photos on eBay, I knew I’d be able to fit them on the bike with just a few tweaks.

After doing a “Buy It Now” in eBay, it only took a few days for the controls to arrive. The eBay description said I was purchasing a complete forward controls “kit”, but my idea of complete and Custom Chromes idea of complete obviously differ.

The box was missing instructions, but I’m mechanically inclined enough that I was able to assemble the controls on my kitchen table. I had no problems assembling the kit until near the end, when I started hunting for the brake peg. After a bit of head scratching, I realized the box had three fold-up foot pegs and a shifter peg, rather than two fold up pegs, a shifter peg and a brake peg.

I contacted the eBay seller via eBay’s messaging service and tried to track down the company’s phone number. I did manage to find a possible number via Google, but the mailbox was full.

A bit frustrated, I tracked down Custom Chrome’s contact information and left a harried message on their voicemail.

i admit, I threw my weight around as a crack motorsports blogger, letting them know the product review I was working on probably wouldn’t be that great if they or their dealer didn’t get their act together.

A few hours after my flurry of emails and voicemails, I got a call back from the eBay seller, who apologized for the problem, saying these packages drop-ship from the manufacturer. He arranged for a footpeg to be rushed out to me. In our brief conversation, I did find it odd that he mentioned how cheap the Custom Chrome forward controls are that I selected compared to some of their other, pricier options.

He did send me some basic instructions for installing the forward controls. I was a bit annoyed that they called for me to cut down and drill my shifter knuckle rather than just including the part in the kit. The brakes lacked any real instructions.

Shortly after I got off the phone with the eBay seller, I got a call from a business development executive at Custom Chrome. I told him about the Oden Motor Shop blog, the Ironhead project, and the review I was writing on the forward controls. Like the eBay dealer, he mentioned the low quality of the forward controls I purchased, saying they were actually the product of a company they acquired several years ago.

So, after all of my parts arrived, my expectations for the Custom Chrome forward controls wasn’t too high. Because of my low expectations, I wasn’t too upset to discover just how crappy these forward controls actually are.

On the plus side, they bolted on easy.

And that’s it.

Once they were on, I mocked up the positioning and saw that the shift lever was too close to the peg, and the brake lever deflected so far forward that it hit the front fender.

Essentially, these forward controls are too far forward and too high.

Modifying these controls wouldn’t be too big of a deal (if you don’t mind trashing your existing controls) to make this kit work with the ’77 Ironhead, but it would be nice if Custom Chrome just mirrored the left controls to the right rather than providing a fancy bracket with mount points for a master cylinder.

But I didn’t bother modding the Custom Chrome controls. When I got on the bike to test the positioning, it became clear that it was made from seriously cheap components. I would feel unsafe with these on my bike.

I’ll give CustomChrome the benefit of the doubt and assume it’s top-dollar forward controls are top-notch, but they should really ditch this “value” line altogether.

And until someone comes up with a good quality “budget” forward control kit, I guess I’ll have to keep hunching over to ride my 1977 Ironhead Sportster.



Project: 1977 Harley-Davidson Ironhead Sportster XLH 1000


Some opportunities are too good to pass up. When I saw this 1977 Harley-Davidson Ironhead Sportster, I knew I had to buy it. Fortunately, I just sold the 1984 Honda Shadow VT700C Bobber, so I had the funds.

Mechanically, the Ironhead is in great condition. There’s a minor fuel leak at the petcock, which I plan to fix with a little torque and fuel resistant thread sealant.

When it really heats up, the clutch makes a loud whirring sound when the bike gets really hot. Some have suggested it’s a bad bearing, while others think the primary chain gets some slack as the bike warms up. It’s great under normal riding conditions around the neighborhood, but I’ll need to fix it before any longer rides.

I’ve already purchased forward controls and nine inch throwback risers. I’ll post install photos as the come.