Electrical problems. Why ?! Why always electrical problems ?!!!

[yello80vette]

A few weeks back the heater blower stopped working in my 1980. Of course, first thing I did was check the fuse and, yep, it was blown. So I installed a nice new pretty green 30 amp and it blew immediately. Making sure it just wasn't a bad fuse I tried one more time and, Pow. It blew too. So somewhere there's a short, right? I tested the switch and it was fine. I inspected all the wiring I was able to access and it all appears to be in very good condition. Upon the suggestion of someone and since they're not expensive, I ordered a new blower motor. Thing is, when I removed the old one I found that it wasn't the original as I'd assumed. It had a manufacture date of 2001 on it so the previous owner must have replaced it. Being electrically ignorant the only other thing I could think to do it take the wire to the blower motor and connect it to the ground wire to the blower motor, turn on the power, turn on the blower switch then touch the two prongs where the fuse goes with my tester to see if the light comes on. Well it didn't. So . . . does anyone have any suggestions of anything else I could try to find out why this thing isn't working before I have to tear the entire dash apart to trace every inch of the wiring? Anything . . . ? Anyone . . . ?

 

[Tom Bryant]

I usually have a few jumper wires I have made up with wire and some alligator clips that you can get at any auto parts store. You will be surprised how often you use them once you have them. Hook one to battery positive and the other end to the positive terminal on the blower motor. Hook another wire to the blower motor ground and touch it to the battery negative. The motor will run if it's good. If this works hook the positive jumper wire to the neg side of the blower switch and then turn on the switch and touch the ground wire to battery negative again. If the motor runs there is a problem between the switch and the motor. There is also a blower motor resistor that has 2 or 3 different size coils that control the blower speeds. If one burns out you usually just loose that speed. I've never seen one short out but I'm not saying it isn't possible. Might be worth looking at.

Tom