[Droach6498]

Im trying to figure out my elec problem. One is the tach. While looking under the dash at the steering column there is a brown wire Im surre its froim the distributor to the tach, where it goes through the fire wall its spliced and connected with a plastic connection, its large and connectable, when I took it apart inside is a globe of metal and the wire has a ball that connects to it. I noticed the wire and globe werent connected very well so I pushed them together but the two pieces back to gether as tight as I could, then started the engine. The tach is working a bit better, it now goes up to 2000rpm instead of just sitting at 1000 when revved up. Whats the connection for? Can I get rid of it and connect them together permanately? maybe then the tach will work properly.
I talked to the former owner and the wiring was or is all new except the headlight. Thats where the problem is. The battery light comes on when you turn the switch down and dim the lights the battery light goes off.
I took it apart, the switch, and tried to individually test each connection in the switch to see which one lights the battery light but the switch wont dim when removed from the dash. Im going to try to put it together today out of the dash see if I can get it to work that way, or short out that way whatever the f***k is going on. Nice of him to sell me a car like this.

 

[Jim K]

To help you in your endeavor to fix this electrical problem, you may want to consider getting one of the laminated wiring diagrams that are available. There are also some sights that you can down load various electrical schematics. The previous owner said the wiring was all new? Hmmm something isn't adding up here.. sounds like either they got the wrong wiring harness or didn't get it all corrected correctly.You can buy complete wiring harnesses from various manufacturers that are correct. While I am not sure what year GTO you're working on, for 68-72 the wiring for the dash instruments all goes to the printed circuit plug in unless you have a hood mounted tach. In which case there are wires for the lighting of the tach for night time driving which I think are brown. I've attached some schematics here and here is the link to download your own copies. Plus you can buy the color coded laminated copy on line.

Free Pontiac Vehicles Diagrams, Schematics, Service Manuals :: Schematics Unlimited

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[O52]

In regards to the tach wire, it sounds like you may be describing the fuse holder. There should be a 1 Amp fuse inside.

 

[Droach6498]

In regards to the tach wire, it sounds like you may be describing the fuse holder. There should be a 1 Amp fuse inside.

View attachment 139735 View attachment 139736 View attachment 139737

Yes thats it! So I need a 1 amp fuse that may be the problem. Got my fingers crossed, please god I will go to church every Sunday.
Thanks very much like ive said before I know nothing of cars Im a remmodeling contractor. I do elec in buildings but its not even close to autos. Much more simple, but alot more dangerous.
DR

 

[Droach6498]

In regards to the tach wire, it sounds like you may be describing the fuse holder. There should be a 1 Amp fuse inside.

View attachment 139735 View attachment 139736 View attachment 139737

Oh yeh its a 65 GTO with a 70 RA3 engine, 66 limited slip rear end,a whole mish mash. Im gonna get it though

 

[O52]

Lets go back the headlight switch problem.
Just as a test, pull the fuse for the dash lights and retest for the BAT light.

65 Tempest schematic