the pcm grounds ohm good with key off but when with key on they get high resistance anybody know the cause of this.
the pcm grounds ohm good with key off but when with key on they get high resistance anybody know the cause of this.
You aren't supposed to test resistance on an energized circuit. That's where a voltage drop test comes into play. Resistance is like a static test for an unenergized circuit, a voltage drop test is like a dynamic live circuit test.
Using Ohm's law, you can determine resistance between two points in a live circuit when using the voltage drop test.
What type of issues are you having? IMO while ohm checks have their place, once you energize(complete) a circuit, you have introduced current flow into that circuit.
There are cases where a wire may test perfect during an Ohm test(0 Ohms) but when energized, may allow a huge voltage drop due to(for example) having only one strand still intact. In this case a resistance check would yeild perfect specs, but a voltage drop test would nail it.
Last edited by vortecyota; 08-03-2011 at 09:47 PM.
Ohm out the wires end to end but not through an entire energized circuit.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
The truck isn't cranking I think I have the trans signal hooked up wrong but I was testing grounds on the pcm to ensure that wasn't it and was worried that a power wire was shorted when i found the high resistance with key on. And on the pcm c1 39 black and yellow wire should be the ground at crank to the starter relay right, because there is 9.86 volts here when in crank.
So is it not cranking or not starting?
wont crank with key but will when i jump the starter at the relay
How did you wire the starter?
Similar to the 03 only deference is I used the I/P crank fuse insead of the Under hood fuse. on the PNP switch i used the wire g the park neutral signal to the one side of the coil of the relay and the yellow and black from pcm c1 39 on the other side of the coil to be the ground.
Got me confused. Why didn't you run the original purple starter wire straight to the starter?
i did
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