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Discussion Starter · #1 ·
95 YJ 2.5 auto trans, getting code 41 (alt field) and 46 (battery overcharging). Am getting 20V DC and 60V AC at the battery when its running. Just repaired ECM capacitors and delay start is fixed. Couldn't visually see any damage wires from ECM to alt. Put a brand new alternator in, problem still exists.I just don't understand why 60 V AC!
Any one had this issue before?
 

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60v ac - with a NEW from store alternator?
> ac voltage has me thinking a bad rectifier/diodes
Where are yu measuring Volts?
No added electrical devices - INVERTER ? any modified or aftermarket electrical?

Try removing field wires -
check for voltage on #3 ASD output ?
Check for a ground or voltage on #2 driver ?
 

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Discussion Starter · #3 ·
60v ac - with a NEW from store alternator?


Where are yu measuring Volts?
No added electrical devices - INVERTER ? any modified or aftermarket electrical?

Try removing field wires -
check for voltage on #3 ASD output ?
Check for a ground or voltage on #2 driver ?
60v ac - with a NEW from store alternator?


Where are yu measuring Volts?
No added electrical devices - INVERTER ? any modified or aftermarket electrical?

Try removing field wires -
check for voltage on #3 ASD output ?
Check for a ground or voltage on #2 driver ?
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No, nothing added, all stock original parts. At the battery when car is running. AC is making the battery boil. My Problem initially was extreme delay start, Check enginelight would come while driving but would go before I could check them. I replaced the capacotors in the ECM and it instantly started up, and started giving me codes. Fixed all but 41 and 46. Will check voltages you mentioned, as well as pin 2 and 22 on ECM, will pull it again for re-inspection, and post results tomorrow. I am just stunned by AC voltage, only one component creates voltage in that car!
 

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I would have never thought to check for AC voltage because it should not exist. Seeing that it does exist however only points in one direction in my mind. The Alternator. You do need to verify the circuits outlined above that control the Alternator for sure but it really sounds like the rectifier (diodes) in the alternator is shorted and allowing AC voltage through.
 
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You did NOT say if alt was NEW a recent purchase?


You have battery connected - neg GROUND? nothing is GI proof.

other thoughts -
What capacitors did you change, a specific system ie injectors?
Soldering inside PCM - might require a double check.
 

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Discussion Starter · #6 ·
You did NOT say if alt was NEW a recent purchase?


You have battery connected - neg GROUND? nothing is GI proof.

other thoughts -
What capacitors did you change, a specific system ie injectors?
Soldering inside PCM - might require a double check.
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Yes, it turns out its damaged ECM circuit board. As the man mentioned above, one look at the price of a "possibly defective one"; and I wanna keep on trouble shooting! Th
Fluid Organism Water Wood Liquid
e loose piece is probably the part that came off, but not sure, can any one locate a picture of a printed circuit board?
 

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I read the first post as YOU had just been inside PCM to do capacitors.

YOU did not do the capacitors a sublet maybe?

Tell us about your replacement hunt for the PCM.
 

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Discussion Starter · #8 ·
I read the first post as YOU had just been inside PCM to do capacitors.

YOU did not do the capacitors a sublet maybe?

Tell us about your replacement hunt for the PCM.
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Facebook market place has them all listed wrong, used they run from $500 to 799. Brand new aftermarket at $449 on eBay but O'Reilly is the cheapest at $178 after core, but they are out of stock for mine. How ever this battle is not yet over, I am going to attempt to bridge another wire and bypass the damaged area. Cheap iron, did this damage, I should have spent another 10 bucks and bought a better iron
 

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Give it a try if nothiing else you learning, and growing familiar.
I would suggest you try to get a PCM from Orielly's to be safe - @ the price of a tank of gas.
just be sure to get it temporally installed to check that it works before you put it on spare part shelf.
 

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Discussion Starter · #10 ·
Give it a try if nothiing else you learning, and growing familiar.
I would suggest you try to get a PCM from Orielly's to be safe - @ the price of a tank of gas.
just be sure to get it temporally installed to check that it works before you put it on spare part shelf.
There are electronic repair companies that rebuild these ECMs for just over $100 and grantee their work. Some have great reviews. Problem is they deal with delay start and do what I did (with out damaging the pcb). They can fix the pcb, they would have to send it to where I used to work 38 years ago. Even then, with good eyes, and great tools, I would have not even attempt to fix this. But am so broke, I pulled the schematic, technically speaking, from where its broken, I can go back to a soldier point, add a diod and a resistor and then go straight to the connector pin or the wire. This EMC is shut any ways, worth trying I suppose. and as soon as I get some money, I am putting a new engine, tourq convertor, wiring harness, EMC and a fuel pump. So I can put on 38 tires lol
 

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fixing PCM is a separate career i'll leave details to you.

My 2¢ WHen you can check local junk yards - a spare.
 

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Discussion Starter · #12 ·
fixing PCM is a separate career i'll leave details to you.

My 2¢ WHen you can check local junk yards - a spare.
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Problem solved, topic closed.
YJ brain surgery was successful, I used Cat5e wires to jump broken connections on the printed circuit board and packed it all back with silicone.
 

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