How to check pcm alternator control
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How to check pcm alternator control I have been going thru alternators at the drags, I don't rev over 6500--shifts are computer controlled. I get maybe 6 or 8 runs and the dash lights up and beeps check alternator. I can drive to Florida and back and not a problem. It's only when I go wot. I have a new charging cable, new battery, no frayed wiring, runs great, no other electrical problems. Does anyone know how I can check if it is in the pcm control--E40? I just put on another rebuilt alt and at idle it is charging 14.3 volts--but the others did too.
Any ideas are appreciated.
Any ideas are appreciated.
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I will check RA, I don't know what a decoupler looks like.
OK, Looked at RA------
That looks like the same pulley that comes on the alternators that I have now ? You can turn the pulley one way and it spins the alt and turn it the other way and it just slips.
OK, Looked at RA------
That looks like the same pulley that comes on the alternators that I have now ? You can turn the pulley one way and it spins the alt and turn it the other way and it just slips.
Last edited by dw456post; Jun 8, 2016 at 10:04 AM.
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I received a UPS delivery notice today that my repaired alt will be delivered. It was from a different company than I purchased it from. I called them and they told me that I should buy a OEM alternator for this car and that the Chinese alt's would not hold up in drag racing-- even shifting at 4800. I bought the alt from a company that advertises 100% made in USA, so that was bullshit. I have requested a refund. I will see how that goes.
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From: NYC
It's ACDELCO 92211821 on Rockauto and it is a Mitsubishi exactly like the OE alternator. The price is $187.99 + shipping. I would only buy from the dealer as a last resort. (Don't buy anything from eBay because the Chinese are knocking-off everything.) Rockauto discount code is: 4664944442039756
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That's cheaper than an OReilly Chinese alternator. I'm gonna get one and try it. I just hate buying stuff like this from out of town. If something goes wrong, I have to ship it back and it takes weeks to get a return. That means that I still need to keep a spare.
Thanks for the info!!
Thanks for the info!!
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How do you get it out of over rev "mode" ? I took back 3 alt's back here locally. They checked them and all 3 were showing bad,--not charging. I'm game to try anything. I just ordered a solid pulley from IW to replace the clutch thing and try that.
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Yep, once the dash warning comes on, it stays on--alt is done. I'm going to the drags with the OReilly Chinese alt on my car today. I will see how many runs that I get before it pops. My OEM alt will be here next week 
. OR has a good warranty so I can just take it back and swap it out. Taking it off the car is a pain in the butt. It's down at the bottom, but has to come out the top. Drain radiator, take off intake tube, take off top radiator hose, remove fans---then I have less than a 1/4 inch clearance from the oversize radiator to get it out.
. OR has a good warranty so I can just take it back and swap it out. Taking it off the car is a pain in the butt. It's down at the bottom, but has to come out the top. Drain radiator, take off intake tube, take off top radiator hose, remove fans---then I have less than a 1/4 inch clearance from the oversize radiator to get it out. 
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Oh ok, sorry I didn't get that part.
I have heard something about a diode or
resistor to keep it from doing something like that
Can you put an analogue gauge off of the alt to check voltage temporarily in your car and watch
What happens at high RPM.
I'm just thinking on the keyboard.
I have heard something about a diode or
resistor to keep it from doing something like that
Can you put an analogue gauge off of the alt to check voltage temporarily in your car and watch
What happens at high RPM.
I'm just thinking on the keyboard.