1979 f250 supercab. I have posted a few other threads asking some other questions now. Truck had sat for 7 years. I'm not good a trouble shooting electrical but I can run wire, saulder, crimp and whatever else to do a good job.
Question, I turn my headlight switch on, headlights don't come on and my left blinker light illuminates and stays on. I haven't checked fuses as of yet, but to me that doesn't seem like a fuse issue. Do I have a short or bad ground? Thanks

 

I'd definitely start with you grounds.
if it's been sitting, might have rust and bad wiring.

 

Was the truck doing that when it was parked? It almost sounds like it has the wrong Instrument Panel Printed Circuit Board in it, but with corrosion and mice on top of previous owners, anything is possible...

Each headlight has a ground to the radiator support, and each tail light has a ground inside the cavity for the light. If your negative battery cable runs to your engine block, then make sure there's a good ground between the block and the cab - Henry liked to put them between a bellhousing bolt and the firewall.

Try powering it all up at night and see if you have any faint glows from bulbs which shouldn't be lit. That is a sign of grounding problems.

But I think removing the cluster is in order. Some sort of double-entendre CF going on in there I suspect. You will probably find some bad wiring of some sort.

 

Thanks for the replies. It never had mice in it. Not sure if it was doing it before it was parked my brother who drove it last couldn't remember. I didn't know the grounds were at the radiator mounts. I'll check those tomorrow. How big of a job is removing the instrument cluster?

 

Square the ground cables, start cables, solenoid ground, etc etc before doing anything else. Grind down to bright shiny metal at block, frame, and firewall.

Use new, heavy duty cables, they are junk by now. Any ground or bond to body or frame needs cleaned up too, for headlights &c. It will start better, charge better, etc etc.

 

Not too bad if it's similar to my F100.

I just had to remove the bezel trim, and then there were 4 screws holding the cluster in. I maneuvered it out a bit and rotated to the left and was able to get my hand behind it to disconnect the connector.

 

1976/79 F100/350; 1976/91 Econoline; 1978/79 Bronco with amp and oil pressure GAUGES: D6TZ-10K843-B .. Printed Circuit Board / Marked: D6TF-10C956-BA

1979 F100/350; 1979/86 Econoline; 1979 Bronco with amp and oil WARNING LAMPS: D9TZ-10K843-A .. Printed Circuit Board / Marked: D9TF-10C956-AA

 

Just an update on the lights. Got all the lights working. I haven't taken the cluster out yet though, I wanted to give a more accurate update on symptoms of the dash lights. The illumination lights for the right side are out, right blinker is out as well, left blinker stays illuminated when running lights are on. Is it possible that it stays illuminated because the right side is out? I also read about LED dash lights and would like to replace all of them with LED. Do I have to change any wireing to use LED or is it just simply take the old bulb out and pop a new LED in? Was there only 1 style bulb used 79s dash that someone could tell me which bulbs I need? Thank you very much.

I also have been looking into DIN radio install. I currently have the door panels off to replace with new and there's no door speakers, but there are 2 larger ones mounted in the rear of the cab so at least I have wires already going back there. I read I have to cut a metal bracket after removal of the original and widen the dash plate a little. Besides running a wire to the battery for always hot if there isn't one and connecting to power that turns on for key and ground, is there anything I'm missing that I'm not thinking of? Thanks again!

 

I had this issue before....and by replacing the whole socket assembly (outside at the turn signal) it took care of the problem. There is a metal strip inside the socket that grounds the bulb. Seeing that your in Spokane i'm thinking there's a bit of corrosion in there. You might get away with cleaning the metal strip or the bulb. New sockets are available at O'Reilly's and NAPA. Let us know what you find.

 

Park lamp & tail lamp sockets same: 1974 F100/350 Stylesides from serial number T80,001; 1975/79 F100/350 Stylesides; 1975/91 Econoline; 1978/79 Bronco.