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Been working on bikes for a long time, but this is probably only the 2nd or 3rd Harley I've worked on, and none of them remotely this new.
Bought it recently and it wasn't getting spark. Seems like the PO was throwing parts at it trying to fix it, but did not succeed. Here are some of the critical details. If anyone has any pointers as to what I can check next, it would be greatly appreciated. I have a manual, but it's so generic that it's not very helpful.
1991 FLHTC
- New battery (~13.5V consistently)
- New coil
- New plugs
- Have tried a used ignition module and pickup trigger out of a known good running bike ('93 Wide Glide)
- Cranks over good
- Only gets ~5V at the coil
- Has approx. 4.4 Ohms at the coil
- With 12V directly to the coil, it will produce a spark
- Kill switch, starter relay and all circuit breakers seem good (checking breakers by checking resistance...not sure if there is a better way)
- The voltage gauge on the dash only ever shows 10-11V
- At some point during the diagnosis, my radio mysteriously fried (smoke coming out of it, now powers up, but doesn't make a sound)
- I was comparing the two ignition modules. The one that came with the bike is #32405-91 (correct), and the alternate one that I was trying out of the '93 is #32405-91A. 91 signifies the year it was first used, so the 91A is likely a revision of the original one with some minor differences (just guessing). However, when checking the resistance at each connection and comparing the two, they were TOTALLY different. In my mind, that means they are either completely different by design, or the original one is junk. Either way, neither of them have lead to me getting spark.
- Most of the wiring seems to be in really good shape (i.e. not hacked to shit)
I think the root of my problem is that I'm not getting enough voltage to the coil, correct? The next thing I was going to try is disconnecting the stator. I'm hoping to see that it has a short in it, and it is sucking voltage away from the coil. I'm not even sure if that is possible though. Am I naive to assume all of my grounds are good since everything else on the bike is working normally (pretty much, anyway)?
Any help is greatly appreciated!