Hey yall, my wife got me a 73 F100 as a welcome home gift. This is my first attempt at rebuilding/restoring anything. LittleBit runs and all the exterior lights work however non of the interior lights work, well the gauge lights don't work, nor does the dome. the blinker lights, hi beam, and brake all work, just the gauge backlights and the radio lights don't. Any ideas on where to start.


thanks,
Bo

73 F100 302

 

i would first check any blown fuses, i had the same problem with my cluster but only some work. The lightbulbs in the back of the cluster were loose and wasnt making a good connection. i tighten them and it work out for me.

 

1 Could be you have them shut off at the headlight switch.

2 The switch could be bad.

3 Fuse could be blown.

4 Wire broken or disconected in the feed or ground.

I had a bad headlight switch doing that and my head lights would go out some times.

Thats all I can think of now.


JIM

 

That's a nice welcome home gift. Get a photobucket account, and post some pics of it. As far as your issue, I'd check the fuses first. If you have your owners manual, it gives a diagram of which fuse goes to what. I'd also get a Chilton's manual, they help greatly with work you're doing on it, and this site is a great resource as well.

 

You could always just poke your head up under the dash and pull one out and see if it is blown. It sounds simple but a bulb has a right to blow after 30 years or so. You better be careful though, the plastic backing that holds the bulbs tends to very brittle. I found out the hard way. You can buy a nice set of LED bulbs to replace them all for about $20 or so. They look pretty nice lit up at night plus you can choose your color.

 

Don't try to remove the cluster to check the bulbs. They tend to fall apart from what I am told. You can reach the bulbs easily by laying in the floor and reaching up. A flashlight will help a lot to. Here is a link that has the fuse diagram in it with sizes.
https://www.ford-trucks.com/forums/9...questions.html

 

well how this all started, is i had to pull the cluster out to replace the speedo cable, before that the lights worked.

 

Instrument lighting is done with the Light Blue/Red Stripe wire.

Anything headlight related doesn't use a fuse, the HD switch has a circuit breaker in it.

Do you have a multimeter to test circuits ?

 

Yeah i have a meter, it is such a birds nest under the dash, the previous owner did a bit of a hack job, there are quite a few splices. I have check the connections and they are solid, just not sure where they all go

 

I would get a manual and see what wire in the iso connector goes to the guage lights and test it. Also cleaning up the connector and gauge paper contacts might help. Also not to be insulting or anthing but make sure the gauge and connector is all the way connected.

 

I'm havin the same problem all lights but the dash lights work. The po I guess decided it was a good idea to cut every wire in half and reconnect them butt connectors. I used a test light and I'm not gettin power to the blue / red stripe when the switch is pulled. I don't know if I have a bad ground somewhere that would cause the problem. The aftermarket gauges I think are wired in too because those are not workin either.

 

I had this problem on my '76. I had no dash lights or dome light. If you look at the headlight switch, you can see the slip ring contact on the plastic wheel that turns when you turn the ****. I had corrosion there. I cleaned the corrosion to solve my problem. Unfortunately the contact inside the switch failed a short time later and I ended up replacing the switch anyway.

 

I think I may try that because one time when my lights went out I smacked the panel right above the switch and got em back for a bit but they are not workin again maybe I can get it tommrow. Also another question I have a black wire with a yellow stripe with a funny yellow plug disconnected does anyone know what its for?

 

I already stated the light Blue/Red Stripe wire is for Instrumentation lighting,all of them.

 

Black/Yellow stripe codes to Keyed Power.

You didn't say what kind of plug. An Y-connector ?

That is for Keyed power for options like Speed control