Help with a 1999 Chevy Astro blown fuse?

Question

My 1999 Astro keeps blowing the ECM-1 fuse. This fuse goes to Fuel injectors 1-6, Crankshaft Position Sensor, VCM, & Coil Driver Module (EST). We just replaced the Fuel pump and Fuel filter, and also disconnected the Crankshaft Position Sensor, but the fuse keeps blowing every time we turn on the key. I looked up in the repair manual and could not find out anything about the VCM, & Coil Driver Module (EST). Any ideas/suggestions?

Answer 1

this may not be your problem but might want to check this:

the wires in the door were getting mangled by the operation of the window arm that moves the window up and down. The harness inside the door runs right along side the moving parts in there and the gear arm cut right into three wires in the harness. But still why wasn't it blowing the window fuse? Turns out that the window fuse is a 30 amp breaker type fuse and was stuck closed and would not trip!! That one threw me for a loop for 3 weeks! That's why it was blowing the main fuse.

Sounds like that might be colts problem too, as I notice he had a new window motor put in.

I searched through the whole wiring harness under the dash and the wiring block that penetrates the firewall, over and over before finding this, and that was extremely difficult, you can't even see it let alone get to it to work on it. At least it was worth it cause I found a couple other small wiring problems while I was at it, now everything is back to normal. Actually better than normal, when we first bought the vehicle, it had electric problems since day one that an entire shop full of mechanics could not figure out.. It kept randomly blowing the electric lock fuse, all these years I figured if a shop full of mechanics couldn't fix it, I wouldn't be able to. But in the process of working on those other problems, I found a taped up factory splice that the wires were poking thru the tape and arcing to some metal part above the steering column so I fixed it as well. Now it's all good.

Answer 2

There is a short in your wiring somewhere.  Electrical problems are very difficult to trace.  It's like finding a needle in a hay stack.  The first place I would check is the ignition key switch to make sure there are no hot spots creating a short.  You need a multimeter and 2 years of electrical engineering technical training.