1993 GMC Jimmy Electrical

I am having an issue with parasitic draw. I have ran the problem down to the ECMB Fuse which powers my ECM, Fuel Pump Oil Pressure Switch, Fuel Pump Relay, and the RWAL Module.

When I disconnect the blue cable to the ECM (E1-F16) it dims the test light. So, I worked my way away from the ECM and went to the different things it powers. No dimming of lights when I disconnect anything that it shows to be powering. Can anyone shed some light on what I may be missing? I just purchased a GM ECM and still same problem. I have no clue where to look next. :screwy: :screwy:

Cra-Z,

Up to 35mA is a fairly typical standby current drain for the older ECMs. Instead of a test lamp, connect a milliammeter and get a quantitative reading.

Ok.. I will check that out. I have now started testing the grounds. Voltage drop tests show a few errors from what I believe. Two of the grounding points are showing a voltage drop of .010. Shouldnt this be below .006 ??

This is what I am getting...

- at the battery post to the end of the battery cable at the engine block: .004
- from the battery post to the two ground points on the back side of the left head (where the ECM ground points are): .004
- from the battery post to the ECM harness at pins A1 and A2 (System ground): .010

Thanks for the response Blue Bowtie.