Mechanics

WHAT WOULD CAUSE MY 12V PINK POWER WIRE RUNNING TO MY ICM, AND IGNITION COIL TO BE POWERLESS?

1996 Chevrolet S-10 • 147 miles

Hi I have a 1996 chevy s10 truck/ with a 4.3l v6 vortec. A few months ago the batterey, the alternator, and the fuel pump were all replaced to succesfully get the truck running. Witch it did for a short time. The truck ran great with no issues for a few days. One night we started it to show a friend, the next morning the truck was dead. We tried and tried to get it started but no matter what we tried it would not start. So we moved on to doing some basic diagnostics and came to the conclusion that we did not have any spark or fuel. So we proceeded to replace the ignition coil, ignition control module, crankshaft sensor, and the distributor cap. And still we have nothing. No spark and no fuel. So I got a little more in depth in testing and proceded to test the pink 12v power wire leading to the ignition module and ignition coild neither have any power going to when key is on position and when cranking engine.I am at a loss please help me diagnos this problem so that I can proced to fix it thanks. My name is drew.
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Bubby46.da
October 4, 2012.



A bad ECM/IGN fuse # 10 (20 A) in instrument panel fuse block.

KHLow2008
Oct 4, 2012.
I checked all fuses in fuse pannel and all is well, where is my Ecm located at and what is the function of this part? Thank you

Tiny
Bubby46.da
Oct 4, 2012.
ECM is the engine computer, the brain of the engine operating system.

I gather you have used a meter to test the fuse. What you need to test next would be the power supply to the fuse (# 10) with ignition switch turned. Both ends of fuse must have battery voltage.

KHLow2008
Oct 4, 2012.
Ok I will do so thanks, also is there a way that I could possibilly check to see if truely is my ecm? I was informed by a rep at autozone that there is a way to check if my ecm is working correctly or not please verifiy. If there is such a way how would I go about doing it thank you.

Tiny
Bubby46.da
Oct 4, 2012.
I checked the powere supply to the fuse with ignition switch on and it checked out.

Tiny
Bubby46.da
Oct 4, 2012.
If you have battery voltage at the fuse, it would mean there is a break in the wire circuit between the fuse and the ICM, etc.

KHLow2008
Oct 4, 2012.
Is there any way you could provide a diagram of that circut, and does that rule out the ecm then?

Tiny
Bubby46.da
Oct 4, 2012.
I checked the voltage by turning the key to on and using a led light tester on both sides of the fuse, and both sides lite up meaning there is power there. Is that a suitable test for what you were describing?

Tiny
Bubby46.da
Oct 4, 2012.
Yes, the test is correct. The fuse supplies power to the fuel injectors as well. If you do not have battery voltage to the fuel injector Pink wire, that would mean there is a break in the circuit between the fuse to the exterior.

The schematics are rather messy as they link 4 pages which are too small unless I enlarge them which would double the pages.

At the moment you do not need the, Confirm you have battery voltage ath the pink wire to fuel injectors, crankshaft position sensor, ICM and ignition coil. If no battery voltage is available, the engine would not start. This wire circuit also feeds the ECM.

KHLow2008
Oct 4, 2012.