how do you test a voltage regulator

[kxnomore]

This is the second time I've had a zero charging situation. The first time it happened I changed both the alternator and regulator. Things were fine for a few months, but now my battery is dead again, and again, there is no increase in voltage while the truck is running after jumping. The voltage at the battery is 10 volts running or not.

So rather than just start changing parts, does anyone have any good tips on the correct way to check the regulator? Do they fail often? I have a hard time believing it's the alternator, as these usually last a long time, I've always thought...

Thanks in advance to anyone who can help with this ongoing issue.

Here's a pic of the truck just because I know you all need pics!

[truckdude239]

just get rid of them unless you want a oringal truck swap overt to an internal voltage regulater takes 30 mins using click here . i got my alt off an 83 Chevy k-10 pick up with 350 http://www.partsamerica.com/ProductD...ype=11&PTSet=A
i got tired of no charge problems this fixed mine since and its easy ,not to many people would notice, not to mention more stable and more amps

[kxnomore]

okay, you win. time to break my rule of keeping things stock.

that does look easy. One question though- will the amp guage still work normally?

[Gray Ghost]

I swapped over to the Ultima 01-01260....comes from a 1987 Silverado 350. 93 amps and a one wire setup that's very easy to do.

[eric67m]

I found one Napa dealer that had one, never saw it but they would take my regulator into the back. My old one was blown up. Bought a new cheap one, blew it up. They replaced it twice before telling me they would not anymore.

I eventually replaced it with an internally regulated alternator. On my new truck it was one of the first things that I did. Well worth it.

[truckdude239]

yes the amp gauge will work the same, i know my idiot light does, edit here is a 78 amp http://www.partsamerica.com/ProductD...ype=11&PTSet=A

[Andy4639]

Just take a volt meter to the battery. Before you crank the truck check voltage reading. Then crank truck up and it should be reading 13 - 14 or better volts while the truck is running the voltage regulator is working if it's what it was before or less the truck was cranked it's not working.

[whatnow123]

Originally Posted by truckdude239

yes the amp gauge will work the same, i know my idiot light does, edit here is a 78 amp http://www.partsamerica.com/ProductD...ype=11&PTSet=A

How do you wire you the amp guage to work? Thought converting this "killed" the amp gauge?

[Andy4639]

I converted mine and it still works as good as it did. Hardly enough to matter. I put a volt meter gauge in under the dash so I knew what I had.
Hooked to the unfused terminal in fuse block and grounded it.

[truckdude239]

just follow the directions in the right up and it should work all the conversions does and make a big jumper wire for the gauge

[Andy4639]

This is what I go by in the truck it tells you exactly what you need to know. The amp gauge never moved through all this.
Here it is at idle with just the radio playing.



This is it with the radio,A/C and head lights on.

[willis0107]

get the truck started and then pull your negative lead off Does it still run? Yes Your regulator is junk NO your alternator is junk simple three minute check. you can also read the voltage while you have the negative cable disconnected from the battery. take a multimeter and read your DC voltage 12.5-14.2 is acceptable anything below that i would start checking for grounds in the cabeling especially since you have replaced the regulator once already check your connector where it plugs into your regulator make sure that the pins inside are clean and free of dirt. also make sure that none of the wires are broken off the pins . I had this happen to my old truck where the negative wire was broken off inside the connector and i replaced alot of stuff before i figured that out.

[stope4]

I'm leaning towards the possibility you may have a short somewhere. If you already replaced the regulator, it's possible you have a newer electronic one that doesn't have an adjustment. If you went strictly original replacement, then it has an adjustment and the way to adjust is a little complicated. More effort than it's worth. I'm sure someone on the board can explain how but it will hurt your head. Get the electronic replacement for $15 and replace the cover with the one from your original. You'll be surprised at how similar it looks. That will be every bit as reliable as an alternator with an internal regulator.

[DavesRide]

I just got off the phone with the oldest of GM tech's I have worked with that would answer the phone after 8:00. Here is my tip of the evening.
He states that the regulator will not work if the Idiot bulb is burned out. The regulator needs to "see" the voltage drop from bulb to kick in. I actually called him to ak him about the full field "get it going" trick, but I reread your original post and realized it was already working and the trick is for new parts. So that's my help today.
Light should come on with key on engine not running. running it should go of after a second or two.