When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Before I order parts Im asking for backup on my diagnosis. Same 91 FLHTC been chasing and having good success with electrical issues.
Shes back to intermittent starting. Diagnosis so far: Battery passes all tests. Wiring at starter relay, and grounds checked and some wires replaced and upgauged. Starter Relay passes all tests.
What doesnt pass is voltage drop test from battery positive to starter solenoid wire, when under load. Manual says < .20, mine is 1.55 Vdc. Thats a lot of wiring and distance from the battery (new cables) thru the main CB to IG switch, over to handlebar switches then back to starter relay and finally solenoid. Ive suspected old corroded starter switch for awhile. So I took it apart, used contact cleaner and air a few times and same problem. So I did a voltage drop test from the OFF switch to the Start switch (maybe one inch?) and voltage drop was .60 volts. That seems huge for inside a housing.
Bottom line, I think Ill get a new OFF/START switches and get in there with the new wires from handlebar to the starter relay.
Please throw me some stuff to try and verify before I do this open heart surgery. ( guess its not that big of a pain ) and I think while I have the front fairing off and gas tank lifted, Ill look at replacing the Red wire from main CB to Control CB up front. That will get me damn near a new starter circuit.
That’s never been done, and I know that you know it’s a real PITA to get my year model IG sw out. I’ll look at the procedure when I’m inside the front fairing though. Thanks
NO NO NO. Don't go to the trouble of a new start switch, won't help.
The starter button/switch only activates the starter relay. The power that's sent by the relay to the solenoid comes off the accessory circuit.
So, do your volt drop test starting at the solenoid (1.55 ?) then at post 87a of relay, then post 30 of relay, then at connector of big yellow ACC wire that comes off the main switch and you'll get it narrowed down.
BTW, are you checking voltage drop - as in meter connected to ground checking difference from battery volts to load volts or with the meter connected between positive post and test point of circuit?
I've got to change tires today but will try to check back as I can.... don't waste time and money on start switch. Yes, you can do an extra relay, real simple but it's not like doing one on a Dyna or a Softail. You're subject to fry radio and gauges if not done correctly.
Here`s a crude drawing I made to show the wiring for the second relay.
Note: Even if you add the second relay, you should still periodically clean all connections at the circuit breakers, start relay, solenoid, battery cables etc.
Also inspect the contacts inside the starter solenoid.
Here`s a crude drawing I made to show the wiring for the second relay.
Note: Even if you add the second relay, you should still periodically clean all connections at the circuit breakers, start relay, solenoid, battery cables etc.
Also inspect the contacts inside the starter solenoid.
86 is a ground post, so on both relays it should go to ground. 87 on original relay should go to 85 on new relay, other than that, the rest is correct.
These type relays were used alot in controlling cooling fan motors on many a vehicle.
As long as 85 and 86 are used to control the relay in can work wired either way.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
Run and Start Switch R&R Maybe
