Electrical Issue with 12/72 horn-brakes-flashers

[MyTwoToys]

I have a 12/72 (73) FJ-40 I did a complete frame off build on. I have had it on the road for about a year and recently I noticed the brake lights were not working. So I looked at the fuse and it was blown. Put in a new fuse and it blew as soon as it touched the fuse block. (good sized spark) I put a meter on the posts on the fuse block, (not an electrical guru by any means) and it showed 12.72 volts. Looks like it is getting straight juice off of my battery. Did some digging and put a ground on my Alternator to my battery and then one to my fender as well from another posting I found. Still pulling 12.72v on the block. I am assuming I have a grounding issue. Any hints, tips, tricks to try and find out where this might be? Is there another point I should be grounding? My flashers, horn and brake lights were working when I finished it last year. Here are some pics. (Not sure why all my photos are getting flipped Sorry.

Help is appreciated. Thanks.

 

[B y r o n]

Sorry, had to fix this:

 

[Xpnsv72fj]

Sorry I can't help but I wanted to say your 40 looks awesome!

Josh

 

[MyTwoToys]

Thanks Josh and Bryon. Byron, I tried a bunch of stuff to rotate the image and it kept refusing to work. Many thanks. That is what I get for using the default MS image software tool on my PC.

 

[georgia fj40]

Fastest way for you without getting involved in ohm alot of stuff would be to remove all the light bulbs on that circuit. replace fuse again, push brake petal, does it blow now? if so brake switch. If not put bulbs back in one at a time and push brake petal after each one until you find which one blows fuse. Then inspect wires, bulb holders etc. for the one that blew the fuse. Just looked at prints for your ride, if wiring is original/stock then you have a trailer light socket switch. Make sure it is not on and a wire is chafed on the trailer harness. Also I personally had a flasher unit with a internal short once that was blowing fuses. check this site out. let us know if we can helpColeman's Electrical Schematics and FSM File Retrieval

 

[78fj40mg]

I have a 12/72 (73) FJ-40 I did a complete frame off build on. I have had it on the road for about a year and recently I noticed the brake lights were not working. So I looked at the fuse and it was blown. Put in a new fuse and it blew as soon as it touched the fuse block. (good sized spark) I put a meter on the posts on the fuse block, (not an electrical guru by any means) and it showed 12.72 volts. Looks like it is getting straight juice off of my battery. Did some digging and put a ground on my Alternator to my battery and then one to my fender as well from another posting I found. Still pulling 12.72v on the block. I am assuming I have a grounding issue. Any hints, tips, tricks to try and find out where this might be? Is there another point I should be grounding? My flashers, horn and brake lights were working when I finished it last year. Here are some pics. (Not sure why all my photos are getting flipped Sorry.

Help is appreciated. Thanks.

View attachment 1265463

View attachment 1265464

View attachment 1265465

There's only one way to fix your problem, sell your 40 to me and I'll fix it!

Beautiful rig!!!

 

[B y r o n]

Thanks Josh and Bryon. Byron, I tried a bunch of stuff to rotate the image and it kept refusing to work. Many thanks. That is what I get for using the default MS image software tool on my PC.

I just used MS Paint to rotate it. Saved it to my Desktop and then uploaded once flipped.

 

[MyTwoToys]

Fastest way for you without getting involved in ohm alot of stuff would be to remove all the light bulbs on that circuit. replace fuse again, push brake petal, does it blow now? if so brake switch. If not put bulbs back in one at a time and push brake petal after each one until you find which one blows fuse. Then inspect wires, bulb holders etc. for the one that blew the fuse. Just looked at prints for your ride, if wiring is original/stock then you have a trailer light socket switch. Make sure it is not on and a wire is chafed on the trailer harness. Also I personally had a flasher unit with a internal short once that was blowing fuses. check this site out. let us know if we can helpColeman's Electrical Schematics and FSM File Retrieval

Thanks. Will do. Yes, I have done some business with Mark. He is awesome. Diving into electrical is not my favorite as it takes lots of patience. I really like to know what I am doing and just get it done. I will keep you all posted. Thinking I may take the flasher unit out of the circuit and see what happens first as my tail lights and blinkers work individually. I guess it would then be on to my brake light switch.

 

[bikersmurf]

I'd also look at the wiring for the back up light switch, although I don't know if it's on the same circuit. Mine rubbed against the ebrake drum and kept randomly blowing the fuse.
Rather than keep blowing fuses, I picked up a self resetting breaker... If it's overloaded it would trip. It resets once it cools down.

The Ambo I have has better breakers... You push a 'button' on them to reset. They are the blade type fuses though, and may not be available for cruisers.

 

[MyTwoToys]

Ok, Update. I did a bunch of trouble shooting and here is what I found so far.
I pulled out the horn, brake light switch and Flashers. I still get the 12.78 volts off of the fuse block. Reattached items one at a time made changes etc... nothing. Put everything back together and now my blinkers don't work. Just a bit frustrated. Next step will be to pull the fuse block to see if there is anything behind it that is causing an issue. I did look up the wiring diagram and it says only the horn, brakes and flashers are on the #2 fuse (20 Amps) Any other thoughts? Thanks again.

 

[georgia fj40]

horn relay? Colum wiring harness from horn switch? I think there is a fuse holder buried in your dash for flashers/turn signals. You have to remove cowl vent cover, and then cowl louver to see it (on hood). Also check where your harness goes through the fire wall? Grommets worn/cracked?

 

[MyTwoToys]

Ok thanks. Will do. Been pretty crazy but will try to update if I make progress this week.