Voltage regulators keep frying

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pjc360

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Today i noticed my volt gauage was getting pretty close to pegging so i grabbed my charging system analyzer wich is a belden and hooked up to a ground and to altenator output charging wire with the hedalights on dim and number 2 light lit up and stayed lit up. I read the back and it says if light 2 is on the battery is good but its not charging and it says field/regulator open. What can cause this? is my altenator toast and sending to much voltage to the voltage regulator? I dont understand because it says battery is still good but field/regulator is open. I have another voltage regulator plus a life time warranty on the regulator i have and i can put a new regultor on and it will be fine for about a month and eventually they will fry this is the second time this has happened. The altenator i got brand new but i had the regulator wired wrong when i installed the altenator and quickly figured it out and got it wired up correctly. So is there a chance my altenator got ruined during the short time my voltage regulator wasnt wired up right and now its frying any voltage regulator i put on after a few weeks? Thats the only thing i can think of my field wires are wired up correctly and my altenator charging wire goes straight to the starter seloniod and on to the battery.
 
First, see what volts from battery terminal on alt , If over 15- check alt for grounded field. All parts stores chinese bs. Take alt to local alt guy, he can test..
 
The tester said my battery was fine but it was not getting a charge and that the voltage regulator field is open. I'm just wondering what can fry a voltage regulator. I think my altenator is fired and there for it keeps frying the voltage regulators. The green from voltage regulator runs straigh back to the altenator then the blue wire from my voltaage regulator runs to the altentor and then down the firewall to the ign side of the ballast reistor. According to ll the draw ups i have seen this is wired up right. Like i said when i first got the altenator i hooked it up and ran it for a few days not realizing that the blue field wire from regulator was wired to the coil side of the ballast and not the ignition side, so i swapped it over to the ignition side of the ballast and kept going and since then i have fried 2 brand new voltage regulators within about 2 months. So i am going to go get the altenator tested tommarrow and if it is bad that is what i am going to assume was the reason for my regulators frying. I cant think of any other reason for them to keep frying. The field wires are wired up right and i have an extra ground to the voltage regulator and the paint behind the regulator is sanded and it has the toothed washers so i know the regulator is grounded as well. only think i can think of is the altenator must be bad and its whats causing them to fry.
 
I'm thinking those few days i ran it not knowing that the blue field wire from the voltage regulator was wired to the coil side of the ballast ruined the brand new altenator i got. The altenator i got was nothing fancy just a standard 55 amp reman napa one for 50 bucks. I'm just hoping the napa in the town i am in will honor the warranty for the altenator because i purchased this altenator from a napa store in missoula and i am currently in salmon idaho on a job and i can see this napa saying since you didnt buy it from us we cant warranty it even tho it was from a napa store. If they do that i guess i will just wait till i go to missoula again and exchange it for a new one under the warranty.
 
Does your alternator have one or two field terminals? If two terminals, one of them needs to be grounded to case of alternator with a jumper wire, the other terminal is to be connected to the field terminal of voltage regulator. Which terminal is grounded, and which goes to field connection on regulator does not matter.

Test continuity of wire running from voltage regulator’s field terminal to alternator’s field terminal by first disconnecting each end of that wire; using ohm scale see if there is a reading close to what you get touching probes together, or a big number or rather high resistance. If a big number you have a broken wire somewhere and needs to be replaced.

Secondly, if voltage regulator’s does not have a good ground, it will not function correctly. Test for voltage drop between voltage regulator’s base, and negative terminal of battery with VOM by placing one test lead to Negative battery terminal and the other to base of regulator set on 20 V scale. If there is a reading of 0.10 volts or higher you have a bad ground.

Correct bad ground of regulator with a ground loop by running a #14 wire from one of the regulator’s mounting screws back to battery’s negative terminal, and while you are at it continue ground loop to electronic spark controller if so equipped.

Now test once again for open field condition.

If you are still seeing open field condition, remove both voltage regulator, and alternator and have devices tested by a shop that rebuilds alternators. They will be able to pinpoint any problem, or problems, and recommend a fix.
 
What do you mean one of the fielld terminals needs to be grounded? the instructions i got on wiring the fild terminals never showed a ground wire? So what you are saying is i need to get a jumper wire hook it to on of the field terminals and then to the case of the altenator and it doesnt matter wich one? My altenator tested good and i just got a brand new voltage regulator decided to try something other then the borg warner selects i keep frying so i put a wells voltage regulator on wich im thinking should be better because its old enough to where it sys made in usa right on it.
 
I changed over from a 5 pin ignition module and a 4 prong ballast resistor to a 4 prong standard ignition module and a standard 2 prong ballast and i just wired up a brand new ignition module connector and my volt gauage is not moving with engine rpm but it does still move when i turn blinkers on or headlights on.
 
pjc360 said:
my volt gauage is not moving with engine rpm but it does still move when i turn blinkers on or headlights on.
Click to expand...

That could be good. If it is keeping the battery charged at idle, it won't have anything to "make up" when you rev the engine. Do you really have a voltage gage and not an ammeter? Regardless, if the alternator is always supplying the requisite power for accessories, the battery won't be called on to contribute.

It would help a lot if you told us the year of the car, what type alternator (old round back or later ~74+ square-back), and what voltage regulator (old rectangular black box w/ screw for FLD wire or later thin square box w/ triangular connector). Photos always help too.
 
91 dodge ram truck wells voltage regulator napa reman altenator with two field terminals on the back charge wire runs to the starter selnoid. field wires are wired correctly battery is good.
 
Me quoting me:
Does your alternator have one or two field terminals? If two terminals, one of them need to be grounded to case of alternator with a jumper wire, the other terminal is to be connected to the field terminal of voltage regulator. Which terminal is grounded, and which goes to field connection on regulator does not matter.
Click to expand...


This is true if you had a single field wire regulator and alternator, and had installed a newer stile two field square back regulator. Where you have a 1991 vehicle; disregard the above advice. Silly me; thinking you had an A Body up-graded with a 360, and other mixed and matched goodies.
 
My 91 Dodge Ramcharger does not have a voltage regulator, everything is controlled by the computer, in the drivers front fender. Never seen a VR on a 91 and up.

barracudadave67
 
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