A quick voltage reg. question

[Anonymous]

Can voltage regulators be "bench" tested at the major auto part stores like batterys/alternators/starters ?...If not, what is the volt/multimeter procedure to eliminate the voltage regulator as being the culprit in a short/circuit problem?

 

[LaGrasta]

To my knowledge, thay can't be tested at your average auto parts store. If it's not your gen/alt, then it's probably the culpret.

 

[Anonymous]

Some stores can do it, call first and ask, they should be able to tell you. Many alternator test machines also test voltage regulators.

 

[Lazy JW]

The basic procedure for isolating the regulator is to bypass the regulator and temporarily jumper full voltage to the field. This is known as "full fielding". You need to know how the unit is configured so as to know how to properly test it. When you full field an alt/gen it should put out max voltage ( 12 volt system can go as high as 20+ volts) so don't hit it for very long or damage can result. A good shop manual will have the proper test procedure. There is more to it for a complete regulator test as far as exact voltage/current ratings, but it isn't too difficult once you learn how. Most modern regulators are non-adjustable so it is basically a pass/fail test.
Joe

 

[Anonymous]

Measuring the battery charging voltage has always worked for me. Make sure the battery has a full charge. Start the car, and read the battery voltage which should be something like 13+ volts. Rev the engine, and the voltage should increase to something on the order of +/- 14.5 volts and stop rising. If it fails to increase with engine rpm or exceeds 15 volts, I would suspect the regulator and replace it. The last regulator I replaced was putting out 17 volts. Sure made the headlights bright, but it tended to boil off the water in the battery.