voltage regulator problems

[jakecorn]

Guys,



I have a 1990 Dodge diesel with the external voltage regulators. I have went thru 2-3 the past two years, and now the truck burns them up within five minutes. When I first install them the volt gauge moves back and forth with the engine RPM, then goes way to the left indicating no charge (about the same time they get really hot and start to smell. I have given up on parts house regulators long ago, and now am using Mopar regulators. I have replaced the connector with a new one, ran an extra ground to the regulator and also an additonal ground to the firewall. I also have moved the regulator over a few inches, to a new spot on the firewall. I also have replaced alternators. Is it possible that one of the two wires running to the regulator has a short in it---somewhere in the wiring harness loom? Could it be my alternator or the wires to the alternator? Any help or ideas would be greatly appreciated, thanks in advance for your time.



Jason Wirth

 

[JLEONARD]

The first thing I would do is remove all the ground wres to the eninge and firewall and clean them up. Make sure they have good contact. It won't hurt to add another engine to fram ground.

Also make sure the regulator is grounded well via the attachment screws.

 

[mysteryman]

charging system

first off, The voltage regulators that are available in the aftermarket today have gone threw a lot of internal changes in the past few years. Most of them are just pure junk. They will not take the load ranges (amps) that our trucks demand. The regulator in question was first used in the 1970 model year. It was used all the way up to 1991 . They all looked the same on the outside. But there were more than 2 dozen Chrysler part #'s for them.
That was with good reason! They were for different applications/ improvements ect.
The bottom line is that there were 2 basic regulators. A3. 5 to 4 amp for the small light duty alt's and a 7. 5 amp for the heavy duty larger alt's. Chrysler no longer makes the 7. 5. . Some years ago I had some 7. 5 made. They also have an added feature. They are manually adjustable. This would allow me to adjust the total voltage output of the alt. on each individual truck to exactly what I needed it to be. Many of the early diesels had trouble with over charging the battery. They would boil out all of the water in the battery and blew alot of regulators. My adjustable 7. 5 amp regulator solved the problem cheap and fast! I think I have about 30 of them left.

As for your problem. You need to check that certain things are correct before you just start replacing parts. 1)Your field circuit could be shorted to ground. Perhaps not a dead short but a partial short or an intermittent short. This would cause an excessive load on the field circuit and blow regulators. An intermittent short WILL BLOW THEM AS FAST AS YOU CAN BOLT THEM IN 2) Be sure that the regulator case is grounded well to the body. Sand screw holes and use Nolox or white grease to stop corrosion. If you live in the rust belt (salted winter roads) run a ground wire (10 ga) from the regulator case to the alternator to be sure. 3) Be sure that the neg. battery terminal has a ground wire going to the core support! 4) If you live in the rust belt (salted winter roads) run a ground wire (10 ga or more) from the engine block to the truck frame. Again, use Nolox or white grease to stop corrosion at contact points. (I also use nolox on the joints where body panels bolt together to promote good electrical conduction. )
5) Check the condition and or age of the battery. Running a truck down the road with a very low or dead battery could kill the alt. and or blow the regulator. Alt's and regulators have a rating. Most of our diesel trucks have 100 amp alts. And they will put out 100 amps. But the rating is for PEAK output. They cannot put out full current continuously! That is what you are doing when you jump start your truck and then head off to work with out charging the battery first. The first thing to fail is the diodes in the alt. and or the regulator. As a rule I replace the battery ever 4 years regardless of its condition. I use group 27 deep cycle marine batteries . They have less amps but have heavier plates inside. I also use group 31 batteries when they are on sale. They have stud mount terminals however.
6) The last thing. Check how much load you you are putting on the charging system.
If you are running trailers that are lit up like a xmass tree. You may be overloading the system. . Too many partial shorts or high resistance circuits can also overload the system. This is very common in the rust belt. Road salt and water is what causes these types of problems... This pretty much covers it. Give me a call if you need any more help or want one of my regulators.

PS: My regulator can also be used on the 92/3 trucks if the internal regulator in the computer fails. Hense saving your having to buy a new or remaned computer

 

[Bob4x4]

Please explain partial short

I am unaware of the concept

Short ok open ok hi resistance ok low resistance ok

 

[mysteryman]

it is a figure of speech I used to describe a short from copper sulfate traces

where as the resistance lowers as the humidity raises. (rains) Most people will not understand what copper sulfate traces are or what causes them or how they are affected by humidity . In short, They are caused by road salt and water being combined with copper wire. The corrosion that is produced is copper sulfate. It is conductive...

Please explain partial short

I am unaware of the concept

Short ok open ok hi resistance ok low resistance ok