Ok I'll try and explain this as best I can. I have an 87 Blazer in pretty good shape, all power options, I'm not too sure if this is going to help in the problem solving but I thought I better mention it.I thought that the alternator had gone because the voltmeter/ammeter, was saying that the battery wasn't getting charge. I replaced that, and still it says that the battery isn't charging. Turns out the battery is charging and the alternator was/is fine. I got in the truck today and smoke started coming from behind the dash. This is after I took to my friends brother who is a heavy duty mechanic, and he tells it's fixed, only $50 and I'm on my way. I look under the dash and there's 2 wires coming from a white junction box that are melting. I look at the fuse box, and this *******'s just run a wire in place of the cage/inst. fuse!! I have no idea where to look to find the short. When the 20 amp fuse is in the box, before you turn the motor over, all the gauges work, but as soon as you release the key and it falls back to the on postion, the fuel gauge and the voltmeter die cause the fuse has blown. Any ideas? I hate taking these things to a mechanic where they go on a goose chase and it costs a bloody fortune. I'd appreciate any help for anyone. Thanx in advance!

Des

 

Welcome to the site.

Chasing down electrical problems can be a nightmare, thus the high cost to get them repiared.


Lets start with the alternator. There is a fuseable link within 12" of the alternator, not on the cable that runs back to the battery.

Some basic info. The battery ahs a red wire running down to the starter, the starter has a wire connected to the same post as the battery cable, this wire goes into the cab of the truck and provides power to everthing in the cab. There is also a fuseable link on this wire within 12" of the starter. The other small wire ont eh starter comes from teh ignition switch. When the engine is off, all power comes via the starter, once the engine is running the power comes from the alternator, via the fuseable link.

Now you mentioned a short with some of the wiring off the fuse block. Get yourself a old fashioned headlight bulb. They are big and full of glass. Hook up each connector to each side of the fuse, no fuse in place. The light will conduct current and not blow while you toruble shoot the short. No start wiggleing wires until the light bulb goes out. Look for small cracks in the wiring. IT might be easier to replace the suspect wiring with new wiring.

Do you have a wiring diagram? Autozone has them on thier website if not. Chilton/Haynes manual do as well.

 

electrical can be a real pain in the ****. I may have a schematic for that year if you can't find one lemme know and I'll look and see what I have...