re-wire PCM voltage regulator

[tmarti96]

Seems Like I read an article once on the TDR about re-wiring the PCM to 'go around' it and get the voltage regulator to work. I am getting about 13. 65 V and feel like I should be getting 14-15 like the manual says. I hate to spend 600. 00 for a PCM just to get my voltage up a little. When I let the truck idle with AC on for 10-15 min, the voltage drops, tach quits, AC quits, and then when I get bac on the road, speed up to 65 mph, all is OK again. I just need a little more at idle, I guess. Wonder if I increased idle speed, if this would help. thanks.

 

[Doc Tinker]

tmarti96



If your idle speed is too low, that might be the problem. If idle speed is set to specs, I don't believe that cranking up or bypassing the regulator would do you any good. Your problem is probably in the alternator, maybe a bad diode, rectifier or just plain worn out brushes. If you have a doubt about this, most alternator rebuild shops will test your system for you and advise you on how to fix it. I don't recommend bypassing anything to achieve your desire for more voltage.



13. 65 volts at idle should be plenty, you might have a bad battery.



Doc

 

[Archive]

There is also another test you can do on your Alt... Its called a Ripple Test. . Take your digital voltmeter, put it on AC volts and measure between output of the Alt, and ground. (just like you would normally do on DC volts. ) This will give you some information about how your rectifier bridge is working. . If some of the diodes are out, you will get a high AC reading. The reading should be less than . 5V AC. . (I think that is the spec. ) Remember your Alt is producing AC current and is converted to DC. This is just one check, if this is OK... have it and your batteries checked. . Good luck. .

Bryan