Hello- Same truck new problem 1984 f250 7.5l . Everything seemed great, but truck died a few times in a row. Driving down the road checked the gauges and everything looked ok. Next hing I knew the windshield wipers and heater were going ape. The windshield wipers were going impressively fast. I noticed that when I hit the gas, the speed at which they moved was quicker or slower based on the gas. I also noticed the same from the vent. I was trying to find a good place to pull over but within about 1 minute, I began to smell something burning. I then saw smoke that seemed to come from the instrument panel. We have replaced many things lately, but like I said the truck seemed to be running great. New battery, new starter, new alternator, coil, distributor, solenoid and many more things. Truck is totally dead now, no response from key, or lights or anything. Any ideas???? I am hoping to try to figure it out without towing again. Thanks in advance-

 

Sounds to me like something in the START-CHARGE-RUN circuitry is wrong, I'm going to
guess the voltage regulator and/or alternator are hooked up incorrectly and the fusible links
have been disabled or bypassed. Look for burn wires in that area under the hood. If you've
got burn wires inside the cab, my best advice is to tow it home as diagnosis & repair is
likely to take significant time.

Where are you at (city/state/country)? If you can, click on User CP and fill out the part of
your profile pertaining to where you're located so we can see it.

 

updating CP now- my bad-

 

voltage regulator, alternator and battery are also new and were hooked up by a mechanic but maybe he made an error there. I am checking the fusable links now and will check back after that. thanks for any help or ideas.

 

Sounds like the voltage regulator failed and over voltage the truck's wireing. Not good when you smell buring wires after that occures.

Going to have to check ALL wires and make sure they are not melted/burnt. Get all fuse links fixed properly and check the alternator/voltage regulator. I have delt with this myself and its not fun.

 

My brother had recently dropped the steering column to change out the ignition switch- is there anything there that could cause this kind of issue- the voltage regulator and alternator are literally 2 weeks old.

 

Unless a wire got pinched when putting the column back up, I doubt that could cause this problem, actily replacing the ignition switch usually fixes many electrical problems.

As long as the switched was "timed" right when installed, if not it usually causes the accy side not to turn off causing dead batteries.

 

Take it back to that guy; he may or may not have done something wrong but IMHO he
should be the one to determine that (and make it right if it was something he did).

You should at least call him up and tell him the situation, maybe he'd even go out to its
location and look at it....

I had a burglar alarm professionally installed in a car once, a few weeks later the thing
started making noise all the time, even while driving. I brought it back to the installer,
turned out some wires had fallen onto the exhaust manifold, gotten hot and shorted out.
Don't remember if it was his fault or not but he fixed it for me.

 

when they open... I don't even know where to start though. Car is totally dead. Battery still tests ok- except it sparks when you put the positive on - from what I understand this indicates a short? Where can I look- what can I do- I recognize that I am going to get help from the mechanic tomorrow- I just hate the idea that everyone says how easy these cars are to work on and I can't even figure out what to begin testing.
No lights, no noise- nothing- when you turn key nothing. It seems like such an overall failure should lead to one or two things to check but I don't know that. I checked the regular fuses- I checked the fusable links (the 2 connected to the solenoid) they are both connected. The smoke/burnt smell is still present in the cab- I dropped the steering column and looked behind the instrument panel- I don't see anything burned. Is there a master fuse somewhere that I just havent heard about that I should be checking? Thanks in advance-

 

The master fuses are the fusible links on the solenoid, be sure to pull firmly on both
sides and not just look.

Again, an overcharge situation implies the voltage regulator, look closely there and at the
connections to the alternator.

A spark when connecting either battery cable means there is some sort of electrical
current draw in the system. A tiny spark might come from the memories of electronic
gadgets in the cab but also might come from a short circuit.

A tan wire in the back of the headlight switch is known to sometimes overheat, this can
cause short circuits in that area. A fire in the heater box (leaves & debris catching fire
from the blower motor resistor located in there) can cause problems.

No power in the cab implies a fusible link in, um, I think it's an orange wire (might be
black with orange stripe) that feeds the in-cab fuse panel from the solenoid-fusible-link
connection.

See if any wires have contacted an exhaust manifold and melted & shorted out.