Does anyone know if there is a way to test the voltage regulator in the alternator? I was thinking instead of buying a whole new alternator assembly, that I could just replace the regulator if I could test it?

Thanks.

 

Try Advance Auto Parts,they can test alternator output/regulation.

 

For about $8 you can get an LED lite stick tester. Some auto stores sell it for more.
Fit it with a cigarette lighter plug.
Plug it in and look at the results.
You can see poor battery connections, charge action, charge reduction as the battery take a re-charge after starting, max voltage during running etc.
The only thing it won't tell you is current drain that is excessive. For that a current measuring meter is to be used or a test lamp in series.

If any of these actions are not what they are supposed to be then you start looking for problems based on what is not the correct action.
The key to it's use in interpeting for all the action that go on under various conditions. A voltmeter could tell you the same things but the LED display is much easier to use without having to look at the scale and the needle action.
The key as said above is to have in mind all the actions that go on.

For examples; at cold starting, if the voltage goes low say 11 volts, the battery capacity may be low, low on water, the connection dirty, the alternator not recharging the battery enough etc.
If after starting if the voltage does not go high into the 15-16 volt range, the regulator can be suspect.
If the voltage goes high and never comes down, you are cooking the life out of the battery, running the alternator to hot etc. Most of the time the regulator is the cause etc. This fault makes the headlite intensity change with rpm, can blow bulbs etc.
If the voltage goes high after restart and slowly comes down over about 10 min running time. That's normal and usually all is well. The time it take to recharge after a start is a measure of battery capacity and it's health.
My 02 runs a voltage of solid 14.4 while out on the road in normal running, lights off or on. The regulator reference keep this that tight. This is seen with a digital voltmeter monitor.

Hope I got the points accross for using this simple tool with info on how to use it.
Good luck.

 

Thanks for the advice. I didnt know they sold an item like that. I did have the alternator checked at an auto store, and came back that the rectifier was not working. I ended up buying a reman. alternator, and dont think they sell the regulator individually. Is the LED lite stick sold behind the counter and does it come with any instructions for the various readings displayed. I have some electrical knowledge, but dont know quite everything with power supplies. Thanks for helping out, this is a great site to get info. and advice.

 

If you look on the back of the alternator, on the voltage regulator itself, you'll see 4 exposed screws around the edge that obviously hold the VR to the alt. case, and 2 more screws in the middle. One has a plastic cap over it with only a tiny hole in the middle that prevents anything from touching the screw. The last screw that's fully exposed has arrow pointing to it, molded into the plastic, coming from the words "GROUND HERE TO TEST". With the engine idling, everything electrical turned off, & a voltmeter connected from the alternator's large red output lug to the case, grounding that screw should cause the alternator to go to its MAXIMUM output for that RPM. Revving the engine will make it go to its absolute peak output. If you have an ammeter that can measure ~180A, you'll see exactly what it can do, but don't ground that screw for more than a few seconds at hi-rev or you could damage/explode your battery or damage the PCM, injectors, HO2Ss, or other stuff. The battery will absorb the extra output for a few moments, but the voltage WILL rise.

If voltage doesn't jump over 16 at hi-rev, the alternator is bad or the brushes are worn. If voltage is normally below 13 at hi-rev, but it jumps with the screw grounded, the VR is bad. If voltage is normally OK, don't risk grounding that screw.

 

Holy cow, just take it to an Autozone or Interstate Batteries Distro. We can check all of that out and wont charge you a thing.. And we wont blow up your battery or fry your electical system... Good god.

 

If I needed a dirty rag to burn, I wouldn't go into the zone for it. Nothing personal against you, genshi, but I've had LOTS of bad experience in there, and with the owner personally.