ECM Install

[RAD]

I received my ECM back from Auto Computer Specialist. Was told NOT to hook it up until I found the short to ground.

Of the things I checked was the grid heater solenoids. My voltmeter was reading 12v across the big lugs on both of them. Thinking it was bad, I replaced them with OEM type, NO Ford solenoids. I am still reading 12v across the two bug lugs.

TPS is NOT hooked up.

ECM is in but  NOT hooked up.

The relay in the PDC is NOT installed.

The two smaller wires on each solenoid ARE hooked up.

I have found and cleaned up 4 grounds in the engine compartment.

i have not had the alternator checked yet.

 

Any help will be greatly appreciated.

[W-T]

The two solenoids are "hot" with DC at all times. The "turn-on" or "activate" is the low current command from the ECU (the small wires at the base of the solenoids). Your test is indeed revealing that your solenoids are being supplied 12 volts directly from the drivers-side battery. Take a look at the two black wires (fusible links) connecting to the positive terminal of the drivers-side battery. This is the connection point that you are reading at the "caps" of your solenoids. This is normal unless you deactivate your grids by disconnecting the fusible-links at the battery post. (Sorry...I don't believe you needed to replace these solenoids) 

 

The "short" that Auto Computer Specialists are advising you of is a mystery? Did they inform you of "what circuit" they were specifically referring to? The ECM is all low voltage, low current signal lines and I would think they might have a good idea of "what" circuit was damaged by this external "short"...if they examined your ECM that you provided as a "core" they would be able to advise you of where to look. 

 

The master connector at the ECM is daunting and the signal paths are quite wide in scope...I would call and ask them these specific questions. It is very good that you have NOT powered up your system at this time. They have received funds from you to obtain this rebuilt ECM...you truly must find the person who reviewed your core ECM on arrival. I believe it is "they" who have advised you of this "unknown short"...ok...now, make them tell you what circuit was damaged.

[Mopar1973Man]

Top left corner here is the grid heater wiring and it's very simple. 

[RAD]

yeah it was all my fault!!! i had been working on it quite a bit and checked the wrong wires!!!!

 

it was hooked up properlly. finally got i cranked, i let it run about 10 mun. rpm started fluctuating about 250-350 rpm. shut it off and hasnt started since!!

 

no codes

 

the diagram above and the grounding diagram are very very helpful!!

 

Edited March 12, 2018 by RAD