Question about Cars & Trucks

1 Answer

I am having problems with my battery charging in my 1990 cadillac brougham. It has a new altenator when tested in car it says bad voltage regulator but when bench tested it says good. I have replaced the cable from altenator to battery I have replaced the pigtail conector and still getting the same read. There are two wires that come from the pigtail and look like they go to a relay on the firewall. Wanting to know if this my be a possibility and if so if you know what is ran off it?

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that gotĀ 5 achievements.


    An expert that hasĀ over 500 points.


    An expert who has answered 200 questions.

  • Cars & Trucks Expert
  • 293 Answers

This would be the voltage regulator, keeps the voltage at the correct level if this unit is faulty if will think it is fully charged at 13.8 volts where it turns off the charge when it may be thinking at 6 volts it is full

Posted on Nov 25, 2013


4 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

  • 379 Answers

SOURCE: altenator is not charging the battery

sir , the altenator has 3 wires at the connector correct ? a white/red , a green/white and a black , the white/red wire is involved with a 10 amp fuse to do with the charging meter / gauge , the fuse located behind left side of dash .. the green/white wire is is involved with 2 fuses , a 10 amp ECU fuse and a 25 amp Main fuse located at left rear of engine compartment main box , and the black wire is involved with a main 80 amp fuse at the main box also . both of these 2 wires end up at the positive side of the battery , please verify all these fuses are good . if they are indeed good , then open wiring would be next step verify continuity on black and the white/green wires . i would post a link to diagram but autozone repair info site is down at this time . if ya need more help , please ask .

Posted on Jan 05, 2009

  • 20 Answers

SOURCE: 1983 cadillac fleetwood brougham 4.1 liter battery not charging

check the alternator fuse that can be a fuse link by the battery pole,check alternator voltage on the alternator red wire or connector,it should the same as on the battery ,check ground wires for loose intermitent contact

Posted on Aug 16, 2009

  • 733 Answers

SOURCE: replaced alternator on 1985 Ford Bonco 4X4 302

turn your vehicle on, disconnect the battery, both terminals(while truck is still on) if it dies on you, then either the alternator is bad or wiring is wrong. if it stays on, then you may have a bad battery or voltage regulator. Check the voltage on the battery before you turn it on(should be from 11.5v-12v), when you turn it on if the alternator if working properly you should have around 13v-14v.

Posted on Sep 16, 2009

Testimonial: "This was helpful, but I did not post that I had already performed this check."

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

My 1989 cadillac brougham is not charging alterntor just bin rebuilt can't find problem wot can it be

Can be so many things, special after you changed (rebuilt it) things. Can be a plug, wrongly connected, build in a defective part. A bad dynamo or voltage regulator. Try to find what is working and where the voltage is not coming or to low.
Would be almost impossible for anyone else to diagnose, if a skilled rebuilder can't find what is wrong, when he is working on the car.

Mar 31, 2015 | 1989 Cadillac Brougham

3 Answers

89 dodge altanator. .new battery...truck will run till battery is drained seems like charging system is not working...all grounds are good, there is no external voltage regulator that I have...

The voltage regulator is mounted on the firewall of this truck. There should be a 2 wire plug that plugs into the alternator, one should be green, ground that wire to see if the alternator starts charging. If the voltage output increases then the regulator is bad.

Feb 24, 2015 | Dodge Cars & Trucks

2 Answers

My battery light lit up on dash of my 2008. Mitsh. lancer gls cvt....what does that mean?

Altenator is not charging the system. It could be the altenator, regulator (built into the altenator), A loose wire (bad connection). There is a plug on the altenator that signals this light when a problem occurs. start the car and wiggle it or unplug it and plug it back in, this will tell you if you have a bad connection. To check the altenator you need a voltage tester.

Jun 10, 2011 | 2006 Mitsubishi Galant

2 Answers

Battery no charge

Either the battery is old and won't hold a charge or your altenator is not putting out enough to charge the battery. If the car is running disconect the positve side on the battery and if the car keeps running then the battery is bad, if it dies then the altenator is bad. Could aslo be a bad voltage regulator, but those are in the module.

Mar 15, 2011 | 1996 Cadillac DeVille

1 Answer

I have a 1988 cadillac brougham and i cannot get my alternator to work i bought new ALTERNATOR AND BATTERY AND BATTERY KEEPS GOIN DEAD

sounds like you have a bad wire or short in the wire that runs from your battery to your alternator. you should have a connector on it which is plugging into the voltage regulator. I had the same thing happen with my 86 Camaro a few years ago

Feb 19, 2011 | 1988 Cadillac Brougham

2 Answers

Alternator not charging on a 1998 cadillac deville after i replaced it with a new one and still the same problem, it will start charging if i bring the rpm's up

Before you start changing everything Test. Check voltage at battery with key off it should read 11.7 to 11.9. Now start car voltage should be 13.5 roughly, rev engine to 2000rpm and voltage should climb another 1.5 average. Let off rpms and it should drop back to intial reading of around 13.5. If things don,t test right then its cables or altenator or ground from battery to altenator housing.

Nov 07, 2009 | 1998 Cadillac DeVille

1 Answer

1983 cadillac fleetwood brougham 4.1 liter battery not charging

check the alternator fuse that can be a fuse link by the battery pole,check alternator voltage on the alternator red wire or connector,it should the same as on the battery ,check ground wires for loose intermitent contact

Aug 16, 2009 | 1983 Cadillac DeVille

2 Answers

1990 Dodge Dakota Will not charge

the computer acts as a voltage regulator. it may be going bad

Nov 18, 2008 | 1990 Dodge Dakota

1 Answer


well for starters your altenator is bad because what it is dolinging is over charging the battery hence why it boiled off the water/acid in the battery. the regulater is intergrated into the altenator. there is not a short because numberone your car would not start and two your battery would explode. i never test a battery or altenator at a store like napa or Oreilly's because they are not mechanics ......they are parts guys. your altenator should charge the battery at no more than 14 volts and the average is 13.5 volts. you need to replace the altenator the reason why you are losing a charge is be cause as the car is running the battery is being discharged because the regulator is defective in the altenator. please rate this thanks

Sep 21, 2008 | 1990 Ford Festiva

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

51 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts


Level 3 Expert

80339 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

john h

Level 3 Expert

15148 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides