View Full Version : wiring questions

02-01-2005, 02:31 PM
Hi everyone, just bought a '77 FLH, none of the electrics work except the starter and headlight (low beam only). My winter project is to fix it, so some dumb questions: When the high beam is on does the low beam also stay on or does that go off? The only fused wire is a 16 gauge that goes from battery + to the instrument panel switch. Looks light headlights, taillights, brake lights, starter switch, and horn all go off that (thru the panel switch). Does that sound right? Bike has no turn signals, I'll probably keep it that way. Thanks

02-01-2005, 10:23 PM
Hey Red-Doggy

Welcome to the forums

On a Stock 77 flh wiring system there sould be three wires coming off the positive side of the battery.

1. goes to starter relay.

2. goes to altenator.

3. goes to starter soleniod

A wire from your starter relay goes to the ignition switch to power assys & ignition.

Your best bet is to get a wiring diagram and figure out whats been done or not done.

Low beam does turn off when high beam is turned on.

If you have a fax you can PM me and I can fax you a diagram. :)


02-01-2005, 10:41 PM
rw's gotcha, but if you need more details, go here:


and follow it into the harley twins section where you'll find a complete diagram...


02-02-2005, 01:04 PM
thanks for getting back, my bike does not seem to have a starter relay. I looked in a JP catalog to see what they looked like and can't see one on mine. like I said, that 3rd wire is fused and goes right to the panel switch. bike starts fine. each cylinder has 2 plugs, the bike has 2 coils, if that makes a difference. the other 2 battery + wires go to the stater solenoid and alternator

02-02-2005, 01:24 PM
the starter relay on your mc should be under the battery box to the rear. if you need some help ive wiire a lot of shovels.. let me know the position of the relay is for stock if they have up dated it with the new smaller relay it could be any where in that general area..
curley B)

02-24-2005, 01:29 PM
Hi again, Another problem now is that one of the two wires going to the tail/brake light is shorted out. Can you get at those, or lift the fender, without dropping the tire? Not much room to get fingers in there to release the wire clips inside the rear fender. thanks again

02-24-2005, 10:50 PM
for getting to those rear finder wires , try jacking the bike up from the frame that will let the rear tire drop and give you more room to work , it still will be a little tight but you should be able to get the job done

02-25-2005, 12:41 AM
Wreckers got y'a covered. If you have a bike jack you can unbolt the lower shock bolts and let the swing arm drop with the wheel on. Just be sure and stabilize the bike with blocks under the front wheel (if using a pedestal lift) so it won't tip off the jack .

RW bottomsup

03-26-2005, 01:05 PM
Here's another problem. I'm wiring the brake light. The hand brake lights it up, as does the foot brake. But when I put them both on the light gets extra bright. Once, when I had them both on for a few seconds, a wire got hot enough to melt one of my solder connections. I have a wiring diagram and stared at it for 20 minutes and couldn't get any help there. Thanks

03-26-2005, 02:47 PM
sounds like you might have crossed a wire , try cheaking to see if one of the break lites is not wired to the running lites