Daniel Black

First off my truck is a 1983 F150. The only problem I'm having is with the warning lights and buzzer. It blows the fuse constantly. If I put a new fuse in everything works fine with the key "ON" but when I engage the starter the fuse blows again. I took the dash cluster out and checked every ground I can find. Any possibility of somehow a short in the alternator wiring feeding full voltage to the "CHARGE" light and popping the fuse when the motor starts turning? Maybe a problem or short in the printed circuit board? I thought about doing the gauge cluster with tach swap until I read on here that the underdash harness would have to be changed so that's out. It's not a huge deal. The battery charges and the truck runs as it always has but the truck is very original and everything on it works except this one problem. I'm a stickler for changing sockets, cleaning grounds and replacing wires to keep every bulb and electrical component working but I just can't figure this one out. To be honest it's bugging the crap out of me and could potentially drive me insane one day. Any help or advice would be greatly appreciated.

GhostriderI

The '81 to '85 F150, F250, and Bronco instrument clusters are direct swap. Because the tachometer. was an option the wiring for it is in the harness already (Plug and play). If you use your cluster and just install the tachometer. you will have to change the printed circuit card to include the connections to the tachometer. A '80 cluster (printed circuit board is different) is the one that requires some wiring changes to use in your truck.
How long has this fuse been blowing? Did it just start happening or was it blown for a while and was over looked? Are you using the correct amp fuse?

Daniel Black

Oh, I thought I had read that the plug for the idiot light cluster had less pins than the gauge cluster and my plug goes directly behind where the tach sits in the cluster. The fuse has been blowing for a while. I haven't really bothered with changing it for the last year but after the rear brake line rusted off and I drove without any rear brakes for 3 days before I could make up a new one, without the brake light ever coming on, I decided it would be a good idea to get the warning lights working again. It calls for a 15 amp fuse on the box cover and in the owners manual. I do remember a few years ago when it first started that sometimes the buzzer would work, sometimes it wouldn't. Certain lights would light up, then the next time different lights would come on or sometimes nothing, sometimes everything would work normally. All my dash illumination lights work with the headlights on, the temp gauge works and the gas gauge( sort of) works. Even when the lights and buzzer stopped working the alternator light would still blink sometimes while driving up til about six months ago and now it doesn't even come on. I pulled all the bulbs and checked them and they all work.

GhostriderI

My cluster plugs in between the speedometer and tachometer. I also had a fuel gauge problem, the oem book gave some checks the last step was to replace the oil pressure sender, when I changed it it corrected my fuel indication problem. As to the fuse I am also stumped

Daniel Black

Okay, thanks. I think my gas gauge has a sending unit problem or a stuck float. It shows below empty with the key off like it should. When I fill it up it'll go to full but it only goes down to 3/4 of a tank then stays there. I just write down my mileage and stop and fill it up about every 150 miles.

GhostriderI

Mine would show full sometimes but would drop like a rock to empty I would stop and fill up it would only take half a tank, or work normally and then hang at 1/4 forever and be so close to out I was running on fumes when I filled up before I started using mileage to track I use the 200 mile rule

Daniel Black

Wow 200 miles. I can't manage that with the 300, granny 4-speed, 4wd combination. Usually about 12mpg.

GhostriderI

Had a 25 gal tank (non-oem) that rusted through now had the oem 19 gallon tank

tkad

there is a separate instrument cluster voltage regulator, I suspect it also supplies the warning lights. if bad, it certainly could behave as you have indicated...of course it's certainly not the only possibility