My 94 F150 XLT SuperCab 4.9L, 5 speed manual has 138,390 miles on it. I bought it with 89K miles already on it. Since that time I have put 4 alternators on it. At over $200 a piece, I have had enough. I constantly have a hot elecritcal smell in the cab. The ammeter shows normal but far to the right until about 15 minutes after driving. I have an after market Sony CD palyer that was already installed before I bought it. Does anybody else have similar problems or maybe a solution to mine.

 

Once "jefflaws" comes around he will probabley have a better answer for you. He has great information and troubleshooting tips.

While you wait for that I will tell you what I think it "might" be. It sounds like you have a possible short circuit somewhere inside the cab (since you said the smell is inside). I don't know if the alternator has any type of fuse or braker in case of high amps.

You said you had a "after market Sony CD player" which was there when you bought the truck. That would be the first place I would look. If it has a fuse it may not be the correct rating (i.e. 5amps, 10amps etc) or it may not have a fuse at all and pulling more amps then it should. See if you can't disconnet the CD player from the electrical supply either pulling the fuse if there is one, or un-wiring the hot feed wire to it.

If that is it your amp meter should look normal, not to the high side and you should have no smell. You should get it repaired as soon as possible anything that produces a "electrical smell" is bad and it could end up catching something on fire and then destroying your new truck.

Hopfully jefflaws will be by soon with a better answer for you, until then try what I said. Good luck and let us know what you found.

I forgot to mention why you are going through alternators. If the alternator is constantly putting out high amps the winding inside the motor will get very hot. Over time it breaks down the insulation on the wires that make the winding which in time ends up shorting the motor out (complete failure). It will also sometimes cause the comutator (part of the alternator that the brushes ride on which give you the DC output) to get hot as well this can affect the brushes which may wear prematurely causing carbon dust to get between the segments in the comutator and then causing shorts which further damage the windings inside the motor. You also have diodes inside the alternator after time to much current will cause them to fail.

 

Thanks for the suggestions. I forgot to mention that I have had this truck for over 4 years. Seems to go through an alternator per year. Dealer service department says they have no idea what the problem is. They suggested disconnecting all the chassis ground wires and checking for corrosion. I have done some troubleshooting. Good grounds and continuity from battey to chassis to starter. Oh, I have replaced the starter & solenoid, battery, and positive cable from battery to starter. When engine is just started, I have 14.7 volts from battery to chassis and Ammeter needle sits on the L of normal. It takes about 45 minutes to get the hot electrical smell. Ammeter needle is at M. The needle never goes to the left of center on the gauge.
I don't have any stereo amps that would draw excessive current.