Author Topic: CB750F0 No Running lights for turn signals or tail light  (Read 728 times)

0 Members and 1 Guest are viewing this topic.

Offline Buttmask

  • Full Member
  • *
  • Posts: 86
CB750F0 No Running lights for turn signals or tail light
« on: July 22, 2015, 01:49:47 PM »
So I installed a brand new harness on my '75 CB750F0 from vintagecb750.com

All connections are clean, greased, and in the right spot.

The running lights for the front turn signals and the tail light wont work.

The are apparently getting power, because the turn signals light up when blinking, and the tail light lights up when a brake switch is engaged. I am at a loss and cannot figure out why just the running lights wont work.

Also, the harness came with a small jumper wire, but I have no idea where it goes to.

This is the only diagram I can come across for the F0, pretty sure some of the colors on it arent right though.

Any ideas would be greatly appreciated.

http://home.comcast.net/~bkirchhoff1/pwpimages/CB750/750F1x.jpg
« Last Edit: July 22, 2015, 04:26:25 PM by Buttmask »

Offline Buttmask

  • Full Member
  • *
  • Posts: 86
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #1 on: July 22, 2015, 07:51:47 PM »
Bump, no one? I'm losing it over this one

Offline Desert-SOHC

  • Expert
  • ****
  • Posts: 1,015
  • It's old
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #2 on: July 22, 2015, 08:03:53 PM »
I had the same thing on my 78!! There is a jumper wire on the old harness that you need to put in. It goes from black "ignition" to brown/white.

hope this helps
90 F350 Lariat CS S/C Dually
90 S&S 11SC Cabover Camper
97 FLHTP (under construction)
11 Ranger S/C 2wd

Offline Buttmask

  • Full Member
  • *
  • Posts: 86
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #3 on: July 22, 2015, 08:29:34 PM »
Definitely a help, hopefully the colors are the same for '75 and that works out! Will try tomorrow

Offline Buttmask

  • Full Member
  • *
  • Posts: 86
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #4 on: July 23, 2015, 11:04:10 AM »
Just an FYI to anyone rewiring an F model, the jumper IS the solution. No idea why this isnt in the wiring diagram, thanks Desert-SOHC!!!

Offline Desert-SOHC

  • Expert
  • ****
  • Posts: 1,015
  • It's old
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #5 on: July 23, 2015, 03:17:22 PM »
It took me a few hours of tracing with a VOM to figure it out. Good thing I never throw anything out, I went and looked at the old harness and there it was..............the jumper.

Glad I could help
90 F350 Lariat CS S/C Dually
90 S&S 11SC Cabover Camper
97 FLHTP (under construction)
11 Ranger S/C 2wd

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,902
  • Bought her new 4/75
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #6 on: July 23, 2015, 06:09:47 PM »
Jumper is mentioned NOWHERE. Connect the last 2 unmatched wires in the junction box below the triple trees on the downtube. Viola tail light. How many wires does your front 'turn signals' have?
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Buttmask

  • Full Member
  • *
  • Posts: 86
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #7 on: July 23, 2015, 06:33:54 PM »
For mine(75 F0) each side has 2 plus a ground, orange and orange/white and light blue and light blue/white.

I honestly dont even remember the jumper in my old harness. But did what Desert SOHC said, jump black to brown/white(in the bucket, not the junction box). Everything came on. I seriously wasted probably 3 hours going over everything again and again and boiling my blood.
« Last Edit: July 23, 2015, 06:35:38 PM by Buttmask »

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,902
  • Bought her new 4/75
Re: CB750F0 No Running lights for turn signals or tail light
« Reply #8 on: July 23, 2015, 08:29:12 PM »
+1 on my F0 also  :)
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)