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Battery temp circuit question

Dumb A
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Dumb A

Dumb A

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I don't have any history with this truck, unfortunately. Many of the fuses were missing in the PDC and I was able to figure out from the skematics which fuses I needed. Everything seems to work now except the charging. I double checked green and blue wires for shorts and opens, they checked out good. I have ground on green and no voltage on blue. When I replaced the PCM and checked voltage on blue, it was 8

volts. Batteries were 12.2 volts. An odd thing I noticed today was after running the truck for 10 minutes or so the bolt meter dropped to 0 and the warning "check gauges" came on. At that time I had the charger hooked up to the batteries and battery voltage was 12.4 volts. Very odd!!

I will double check the battery temp circuit tomorrow to make sure I had the correct pins as the numbers are wonderfully small.

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Mopar1973Man

Mopar1973Man

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10 hours ago, Dumb A said:

I have ground on green and no voltage on blue. When I replaced the PCM and checked voltage on blue, it was 8

 

PCM is damaged. I've got a protection fuse mod to stop this issues. Still need to send the PCM in for repair. The blue wire should be +12V after crank signal is sensed. Then the green wire should be variable ground after crank signal sensed. 

 

My alternator shorted out and burned a hole right through the PCM's printed circuit board. @pepsi71oceanhad the same failure and his was repairable through @Auto Computer Specialist.

 

The PCM master fuse is a 20A fuse. The problem is the circuit board can barely handle 5 to 7 amps before burning up. Hence the article was wrote up to stop the PCM damage. I'm running a 5A fuse and still going strong.

 

 

Edited by Mopar1973Man
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Dumb A

Dumb A

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Hey buddy, thanks for your help!!!

 

So I had read about this mod, adding the fuses link to the blue wire and performed this mod prior to installing the refurbished PCM. I will change the 7.5 to a 5 amp fuse. 

 

I got this PCM from Auto Module Source, I feel it didn't work from the moment I plugged it in, but not having much experience with this truck and lack of knowledge is a good recipe for self inflicted oh #@&$ moments. 

 

Thanks again for all your help and support. I will order a new PCM from Auto Computer Specialists.

 

I wish for you and your family a healthy happy future...

 

Mario

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Dumb A

Dumb A

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I was able to take the truck out for a test drive, seemed to go ok. It did set a 0120 code and the throttle did have a hesitation when it set this code. I measured the ac volts as described and got .043, engine hot, at an idle. I cleared the code and will see if it returns. You folks are a great help, thanks.

 

Mario

As for alternators, I will have one of each, Bosh and ND one wire converted by Heielectric in Oregon. That way I have a spare for when I'm up Alaska way having fun....

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