Alternator sensing Wire Mod- Need more Volts
#11
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Thanks again Justin, When I get some time I am going to to post a schematic & hopefully you can look at it so we can confirm what goes where.
I wonder if the * wire already has a resistor on it..we will find out...maybe greater resistance needed.
I wonder if the * wire already has a resistor on it..we will find out...maybe greater resistance needed.
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1997 Buick Pk Ave (Soft Ride) Suspension!
1997 Buick Pk Ave (Soft Ride) Suspension!
#12
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#13
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True Car Nut
the l terminal turns it on, f is fault indication to pcm. * needs to be added like on the h-body and if you hook it to something inside that is keyed it should work. you may need to get a plug that has all the wires. and you want something decent gauge like 12 so it doesnt drop any and gets an accurate reading
#14
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#15
Retired
"With a basic load on, fan on lights on & brakes lights on at idle, volts drops from interior accessory socket reading to 12.2 -12.4 volts..that is huh?? Should it not be kicking out at least 13.6 volts?.
This is always after driving when it gets hot outside.. doesn't help either..
At 1800 rpm with same load, I am lucky to see 13.4 volts....this is not charging the battery very well. "
If you go out to any stock GM car, those readings will be normal......at warm idle, and under a load, you will not get 12.6 volts.....No way will your alternator be charging at 13.6, at warm idle under a load.....
At 2000 rpms, with a warm engine, with a load, 13.4 volts sounds about right.....
As Mike asked, if you have an old battery/bad connection, that can skew the voltages a little lower.....
I don't know if anyone can print the TSB that pertains to this....the TSB has a graph of the output of the alternator for a cold and warm engine, and how voltage will drop, if the alternator is warm, and especially under a load, like for example, at night, when you come to a stop and the lights may dim a little....
This is always after driving when it gets hot outside.. doesn't help either..
At 1800 rpm with same load, I am lucky to see 13.4 volts....this is not charging the battery very well. "
If you go out to any stock GM car, those readings will be normal......at warm idle, and under a load, you will not get 12.6 volts.....No way will your alternator be charging at 13.6, at warm idle under a load.....
At 2000 rpms, with a warm engine, with a load, 13.4 volts sounds about right.....
As Mike asked, if you have an old battery/bad connection, that can skew the voltages a little lower.....
I don't know if anyone can print the TSB that pertains to this....the TSB has a graph of the output of the alternator for a cold and warm engine, and how voltage will drop, if the alternator is warm, and especially under a load, like for example, at night, when you come to a stop and the lights may dim a little....
Though, I can replicate different/higher readings in the winter time vs the summer time. In other words, your chasing ghosts.
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#16
Senior Member
True Car Nut
it is normal, for regular LA batteries. but agm batteries like the one he has like more volts. the good agm chargers are like 14.5. i dont think it matters what circuit you put it on its not going to be much current
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Soft Ride (06-03-2014)
#17
Senior Member
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I have to ask this why is the digital info center volts reporting low by .9 of a volt
When an OBDII reader and VOM both agree it is out by .09?
I am going to get to a PCM scan soon.
Is there an error correction or a way to fix this in a TechII scanner programming method?
Could this be something up with the PCM?
I have since I owned the PA simply been adding 1 volt knowing its been reporting wrong.
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1997 Buick Pk Ave (Soft Ride) Suspension!
1997 Buick Pk Ave (Soft Ride) Suspension!
#18
Retired
Your PCM and OBD reader are probably on 2 different circuits. The PCM takes its voltage reading from within itself and the OBD reader takes its reading from the OBD 2 port. Get a PCM pinout schematic for your car and backprobe the power input to your PCM and compare.
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