[tmmm454]

I am new to this forum, as I have just recently bought a 69 GTO 4-speed non-AC car. The car is just beautiful and the body is just about as perfect as you can get and the motor/transmission are very tight and strong……here’s my problem:

My interior/dash lights fuse keeps blowing out…..so it pretty dark inside that car at night. Also, my windshield wipers and horn do not work…however the fuse to the windshield wipers is fine and not blown. What fuse controls the horn? Does anyone have any suggestions on a fix? I took the bulb out of dome light and noticed it was old and the contact in that light is pretty rusty. I would appreciate any suggestions anyone may have. Thanks. Tom

[Judge Man]

You have a short in the wires that go to that fuse.You need to trace those wires back and check for any bare wires.

[GoatDr]

I had a similar problem and it ended up being the headlight switch. Everytime I turned on the headlights it would blow the dash fuse.

[engineer]

dash lights, wipers and horn circuits all use ground wiring to turn those items on and off. sounds like you need to look at the ground wirings to see if anything is shorted with a power lead.

[kyle_blake]

Make sure the interior dome light is all fixed up without any rust on those connectors.

I have some wiring diagrams for 69 gto, if you like PM me and I'll send em to yah.

I believe if you HORN is rusted out it will blow the FUSE! No word of a lie, my mustang use to blow the fuse everytime I hit the horn!!!

Changed out the HORN and now it doesn't blow!!!
You be surprised, current draw across a bad horn can do this!

Doesn't hurt looking.. A horn is $20 Canadian and you can test it that way.
Or...I believe you have two horns at the front, you can disable one and try the other, see if it blows.

I'm not sure...Perhaps I'm on the wrong circuit.
LOL

[MrPushrod]

Try using a test light on everything.

[tmmm454]

Originally Posted by engineer

dash lights, wipers and horn circuits all use ground wiring to turn those items on and off. sounds like you need to look at the ground wirings to see if anything is shorted with a power lead.

Thanks for the info.....do you happen to know where the ground wires are for the dash lights/wipers/horn? I just don't know that much about the electrical on cars. Hope this is not asking too much... Thanks again. Tom

[engineer]

grounds for each circuit are in different places. There are several dash grounds which must attach to the dash, then the headlight circuit \ interior lights are one, then wiper switch is another, finally horn ground is another which all feed from the dash grounds. If you start with dash lights, ground circuit is part of headlamp switch, but short can come from any socket, bulb, etc. that is on that circuit. I would pull out headlamp switch and start there.

[Pecosbill]

The entire body of the car is the ground circuit. You have one "hot" wire coming from the + side of the battery to all lights and other electrical applications and the circuit is completed where the "other" side of the light bulb socket, etc. connects with a metal piece of the car, such as the dash bezel, which is connected to the firewall, frame, motor, steering column, etc. The negative side of the battery is connected to the engine block, which is then connected to the other metal parts of the car, completing the circuit back to the battery.

When looking for a problem that involves instantaneous fuse blowing, look for a "+ side" wire or connection that is constantly touching metal somewhere. When the fuse blows sporadically, for no apparent reason, look for a "+ side" to metal connection that makes contact when the car hits a bump. When the fuse blows whenever an application is activated (dash light fuse blows when headlight switch is turned on, etc.) look for a short in the switch that turns the application on, a short in the wiring from the switch to that application, or a short in the application itself (a dash light wire with worn insulation touching metal, etc.).

BTW, I don't know about the 69, but my 64 has the dash lights on the same circuit as the tail lights. That was done so that if the fuse blew, your dash lights would go out alerting you to the fact that you also had no tail lights. If your 69 has them on the same circuit, be sure to check the wiring in the trunk to the tail lights, as it sometimes gets pinched and causes a short to the metal in the trunk.