Voltage Regulators

[matty mopar]

Has anyone been having trouble with off the shelf voltage regulators lately? The old mechanical type, not the solid state ones.

I've gone through 3 in the past two years on two separate cars. Both have factory stock wiring. Everything works fine for a while, but they ultimately go. Is it just cheap parts, or is there some issue I am missing here?

 

[KitCarlson]

Have you used a voltmeter to test for voltage drop in the ignition feed to the regulator?
The meter can also be use to check charging voltage and ground connections. Changing parts because they "go" does not help diagnose your problem.

 

[tekslk]

They make electronic ones with a cover to look like the original, I ended up using one 6 years ago and never had trouble again.

 

[68gtxman]

When the mechanical ones "go", they can be easily repaired by opening the case, looking for the melted wire and soldering a shunt across the burned out portion.

As for them failing, check for bad ground connections on the VR. They must have an excellent ground!

 

[67Dart273]

One issue might be a heavier alternator field. They "ain't all created equal. Look in your shop manual. There's a procedure for measuring field current.

 

[BillGrissom]

I 2nd you need to pop it open to find what part failed. If the contacts burned or fused, it could be "alternator field draws too much" (post 5). If the coil failed, it sounds like a design issue since the coil should never see >13 V (its setting), even if the rest of the car has too high a voltage (due to voltage drops). The mechanical system was never very robust and needed constant tweaks. I wouldn't rely on one today (or even in 1972), though it is good to keep for cars that are a museum piece.

 

[67Dart273]

............Well and the thing is what you "think you might be buyin" are probably NOT mechanical at all. Just about any I've seen in parts stores for replacement are ACTUALLY solid state units.

How to tell? EASY. Look at the bottom. Actual "mechanical" VR has two great big wirewound resistors......like this

While the electronic look-alike always has a "clean" bottom sometimes with a PC board

like this....

 

[KitCarlson]

Large field current happens if there is an internal winding, turn to turn short. I think a standard normal field current runs up to about 3.5A. It is also possible for the windings insulation to fail, and short to rotor and ground via bearings. In either case the alternator will be significantly compromised, a new regulator is not a fix.

 

[67Dart273]

Large field current happens if there is an internal winding, turn to turn short. I think a standard normal field current runs up to about 3.5A. It is also possible for the windings insulation to fail, and short to rotor and ground via bearings. In either case the alternator will be significantly compromised, a new regulator is not a fix.

Some of the newer ones, and larger ones, are closer to 6A Someone on here posted an aftermarket, made "heavy duty" 70 type regulators supposed to last