6.2 diesel overcharging

[6.2Patriot86]

I just bought a 1986 M1009 Blazer, and I can't figure out why I keep boiling the front battery, I had the driver side alternator rebuilt, but the passenger side is original as far as I know, does it have a regulator stuck open oris the regulator in my alternator, any information would be appreciated, and if anyone knows where I can get a book on the system I would appreciate that also.

 

[bajaman]

I have the same problem

Sent from my SM-A515U using Tapatalk

 

[MarcusOReallyus]

Regulator is in the alternator. Check the "Testing the Alternator on the Vehicle" sticky at the top of the forum.

 

[Keith_J]

Voltage regulator is defective. Check for battery voltage at #2 connection. Could be an open fusible link.

The #1 connection on the internal regulator is from the idiot light so it should be 0 volts with key off, 12 volts or so key on. #2 should always have 12 volts on the driver's side alternator.

 

[6.2Patriot86]

Voltage regulator is defective. Check for battery voltage at #2 connection. Could be an open fusible link.

The #1 connection on the internal regulator is from the idiot light so it should be 0 volts with key off, 12 volts or so key on. #2 should always have 12 volts on the driver's side alternator.

Where is the regulator located?

 

[6.2Patriot86]

Voltage regulator is defective. Check for battery voltage at #2 connection. Could be an open fusible link.

The #1 connection on the internal regulator is from the idiot light so it should be 0 volts with key off, 12 volts or so key on. #2 should always have 12 volts on the driver's side alternator.

Couldn't it also be the alternator relay? And do you happen to know where that would be located?

 

[MarcusOReallyus]

ALTERNATOR
GEN1 and GEN2 Exciter circuit troubleshooting
http://www.steelsoldiers.com/showthread.php?121589-CUCV-GEN1-and-GEN2-Exciter-troubleshooting

CUCV Isolated Ground Theory of Operation
http://www.steelsoldiers.com/showth...ternator-Isolated-Ground-Therory-of-Operation

CUCV Alternator-symptoms-diagnosis-and-fix
http://www.steelsoldiers.com/showthread.php?54292-CUCV-alternator-symptoms-diagnosis-and-fix

CUCV Alternator Rebuild - illustrated
http://www.steelsoldiers.com/showthread.php?146703-CUCV-Alternator-Rebuild

CUCV Alternator Rebuild
http://www.steelsoldiers.com/showthread.php?60299-CUCV-Alternator-Rebuild-Question

Convert a Civvy Alternator to an Isolated Ground if you busted your case
http://www.steelsoldiers.com/showthread.php?56186-Isolated-Ground-Alternator

Alternator Rebuild Kits
http://www.steelsoldiers.com/showthread.php?136886-Alternator-and-starter-parts-amp-repair-kits

 

[Keith_J]

The regulator is in the alternator. The driver side alternator does not have a relay, it is switched with the key switch through the alternator 1 light on the dash.

Originally, the 27SI regulator was supposed to default to the battery voltage if the sense voltage was zero but with offshore production of all the new parts, it might not be correct.

Using the main battery connection for voltage sense decreases alternator output and can lead to undercharged batteries.

 

[6.2Patriot86]

The regulator is in the alternator. The driver side alternator does not have a relay, it is switched with the key switch through the alternator 1 light on the dash.

Originally, the 27SI regulator was supposed to default to the battery voltage if the sense voltage was zero but with offshore production of all the new parts, it might not be correct.

Using the main battery connection for voltage sense decreases alternator output and can lead to undercharged batteries.

So say theoretically the shop i originally took it to put a 24v alternator on the driver's side would that be the cause of my overload?

 

[Barrman]

Yes, that would mean 24 volts in the truck 12 volt system and 36 volts in the starting circuit. All very bad.