[dans1967]

Own a 67 GTO. When I step on the brake the courtesy light above console lights up, eventually the brake light fuse blows. What is the best way to tackle this problem. Ground issue has been suggested, where is this ground located?

Thanks in advance.
Dan

[Nicks67GTO]

If you want my honest opinion....Call American Autowire or M&H and start replacing the entire system with new stuff. I'm sick to death of jacking around with 45 year old electrical gremilins and i'm an electrician by trade. This fall my GTO is getting completely rewired.

[Nicks67GTO]

Now with that said....I would pull the taillight harness, cut it apart and see whats going on in there. Could be cracked wires. It could be a tail lamp socket. If you cut it apart and nothing is wrong youre only out some electrical tape to re wrap it.

I had to completely redo mine with sockets, new splices, wire replacement throughout it and all kinds of tape. Its a hodge podge of BS just like my headlights and my under dash.

[rohrt]

I have chased a fair number of electrical issue issues. Yours is interesting.

Thing to do is get a schematic for you vehicle and get real familiar with it. Get familiar with what wires go to the courtesy light and the wire that go to the tail lights.

Get a good volt meter to work with and I recommend removing the front seat. Determine what fuse goes to the courtesy light and what one goes to the back tail lights. May need to remove the fuse block to trace the wires.

As Nick said remove the wire wrap and start tracing out the wires. Isolate circuits by pulling fuses and removing connectors to the bulkhead and/or other connectors. Ohm wires out to ground to look for shorts if needed.



I was absolutely dreading working on my 64. It was a complete rats next under the dash. Cut and spliced wires everywere. I had my schematic and took a bunch of notes along the way. Only took about 2 hours to get everything figured out. The dread of thinking about doing it was much worse then the job.

[jeff chmura]

Hey Dan,
Is this something that just started happening or is this after a rewire?
I'm asking because it sounds like the positive for the console is connected to the ground circuit of the brake lights, or visa versa
this is what I do for electrical shorts...
look at the wiring schematic and verify what is on the circuit blowing the fuse. how many lights and what there for. Remove the bulbs one at a time.
Try not to move too much stuff when you remove the bulbs, I'll explain why in a sec.....
remove the bulbs one at a time and apply the brake and see which one blows the fuse.(meaning,when you remove a bulb,the fuse should NOT blow.. no bulb to blow it)
If they still blow regardless of which one is removed, its a wiring problem, If the fuse doesn't blow after removing a single bulb, you problem is isolated to that circuit, most likely that socket/bulb.
In your case, I would start with the console bulb.
If its a wiring issue.... using a test light,with the key off (no power in wiring) connect the wire side of the test light to a POSTIVE on the car.(direct to battery is OK,) Using the probe side of the test light as the ground,probe the center of the light socket.
If the test light DOES NOT light, thats good, that means, the postive side of the bulb socket wiring IS NOT grounded. If the test light DOES light, then you found your short circuit.
With the test light connected and still lit, start moving the wiring around with your hands,take your time here, try not to move the whole harness at one time, you want to move it and watch the test light. A helper would be good for this. The light will flicker or go out when you in the general area of the short. once at that point, cut the harness insulation and visually inspect. Most shorts I find are at where the harness would come in contact with metal (like through the firewall,Into the trunk,bumper,etc...)
Alot of people will get excited yanking of the harness and the test light will go out, thinking the fixed the problem,they put everything back together and call it fixed. the problem is you didn't really fix it, you just eliminated the short for the time being, but eventually it will come back.
Good luck...
Jeff

[dans1967]

I have my work cut out for me this weekend. Great info, will let you know what i find.

[jd66]

Had a similar problem with my 66 with all new M&H wiring, when I lifted the trunk the under dash lite came on and my rail lights did not work as well, all this ties into the ribbon under the carpet from the dash above the emergency brake, what I found was the plug at the ribbon had came partially unplugged, hope this helps. let us all know what you find, interesting problem, as for M&H there the best did the hole car with there system kept the test light on the battery thru the whole install except for the above problem ( I did it) not one short and everything works and my car is a fully optioned GTO. good luck. jd grim 66 gto

[fyrffytr1]

It is also possible to plug the ribbon harness in upside down. Ask me how I know!

[gtoric]

Do you have a tilt column? I've tracked some strange behavior to a chaffed ribbon harness in the column where the tilt column bends.

[dans1967]

Finally put some serious time into finding the problem. Spent several hours following wires, removing the fuse block, checking the bulbs and sockets- to no avail. Dawn finally broke over marblehead, separate all the connectors for these two circuits and then plug back in one at a time and test. The connector at the bottom of the steering column showed it is the harness in the steering column. Took the steering wheel apart and found a broken wire and a shaved wire. A new harness is on order. Now I get to put it all back together, but problem solved.

[dans1967]

Thanks for everyone"s advice