alternator charging problem-post plenum repair
#11
05-22-2011, 10:22 PM
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Engine running/not running whats the volts on the large wire? Rev the engine whats the voltage? Whats the volts to the pcm pin 3? Pcm needs correct voltage at that pin to calculate the field needed. Pcm pin 20 is the field wire. Can use a tach or a dwell meter something to detect the pulses from this pin. Or simple remove said wire field wire from the pcm. This tells you on which side the fault is. Pcm or alternator/wireing.
Engine running for the B+ alt terminal = infinity???
Reved engine = the same.
Voltages from terminals (and ground) in previous post.
I have perfect continuity between the field terminal and pcm pin 20. 0.000
i got 0.007 for the other terminal and pin 3.
Maybe I need to retest...
#12
05-22-2011, 10:26 PM
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Did you connect the ground wire to the BACK of the alternator? Because i left that off, and it would not charge. Also, you may not have tightened it down.
I think that you didn't hook up the alternator correctly after the plenum repair. There is nothing about a plenum repair that would not make it charge unless you did not hook up the alt correctly.
I think that you didn't hook up the alternator correctly after the plenum repair. There is nothing about a plenum repair that would not make it charge unless you did not hook up the alt correctly.
#13
05-22-2011, 10:59 PM
#14
05-22-2011, 11:14 PM
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Just rechecked, from the B+ output terminal from the alternator grounded to the battery (-) terminal I got 27 Volts, it read infinity earlier since I didn't have the correct scale selected on the volt meter.
#15
05-22-2011, 11:25 PM
#16
05-22-2011, 11:52 PM
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#17
05-23-2011, 02:20 AM
Having 27 volt's( r u kidding me)at the alternator and 11v at the battery with a running engine points to bad connection back to the pdc to the battery. But wait a minute you did not check voltage at pin 3 at the pcm? why not? Also check pin 57 for voltage?The field wire is pulsed, again dwell meter or tach can read this pulse or non-pulse or constent. Check for ripple voltage at the B+ on the alt by switching your meter to AC, engine running? Now at the battery engine off meter to AC? Did not ask for continuity only voltage readings. Easiest way to go about this is to remove/cut the field wire at the pcm pin 20, engine running. Note what happens to the voltage when you remove just this wire. Volts go up/down stay the same? I have a feeling about the answers but i dont give the answer of what is should be. I want to know your answer readings.
Last edited by tweeker909; 05-23-2011 at 03:19 AM.
#18
05-23-2011, 08:54 AM
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see my last post. I was checking continuity to make sure I hadn't knicked a wire upon reconnections and I didn't think cutting wires at 11-12pm was a good idea.
I'm not sure why I would get such readings on the volt meter, probably need to pay better attention to my settings and connections.
Sure enough, the fuse was broken down on the edge away from the sight hole. Replaced it this morning and started air purging the system. The truck is running pretty good.
Now on to the check valves to get the vent door under control and check pulley alignment for a very little belt chirp.
I'm not sure why I would get such readings on the volt meter, probably need to pay better attention to my settings and connections.
Sure enough, the fuse was broken down on the edge away from the sight hole. Replaced it this morning and started air purging the system. The truck is running pretty good.
Now on to the check valves to get the vent door under control and check pulley alignment for a very little belt chirp.