: '69 deville 472 'Gen' light stays on



highonchai
04-06-04, 03:58 PM
Hey all, I replaced the alternator the day i bought the car, but the 'gen' light stays on when i start it up and drive it around, it never goes off. is it supposed to stay on? I do need a new battery but not that badly, this one will hold a charge and start the car, but not like it should, does this sound like my problem? or is there something else i should consider? Thanks a lot all!:worship:

Imprl59
04-06-04, 05:16 PM
That light means your alt is not working or not working properly. Could be a wiring issue or a bad alt. Do you have a voltage meter? If so check the voltage on the battery with the car running and let us know what it is.

Steve B.

MMNineInchNails
04-07-04, 12:27 AM
take your alternator and voltage regulator down to autozone and they'll test it for free. Also check all fuses and make sure none are blown. That happened to me, my alt light stayed on and i got everything checked out, and everything was fine, then i checked the fuses and one was blown, replaced it and the light went off.

highonchai
04-07-04, 09:58 PM
Ive done both, my alt is fine, that was my first try, and i replaced all my fuses that even looked like they could be troubled, but i replaced a 7.5amp with a 6amp, i couldnt find a 7.5 amp fuse could that be the problem?? i tried to check with the volt meter but i couldnt get the damn thing to work, ill try tomorrow in the light. Thanks.

DaveSmed
04-08-04, 01:37 AM
What about the regulator? IIRC you have a mechanical points based regulator. they just go bad after time, like ignition points. Should be a little metal box mounted somewhere on the pass. side fender. Did you upgrade the alternator to a three wire or one wire alt.?

highonchai
04-08-04, 12:32 PM
Is the regulator the small silver box (rounded corners) with a couple connections coming out of the bottom of it, one of which comes from the alt? its mounted high on the firewall next to the big AC box. is this part easy to find a replacement for?

And i dont know about the one wire three wire thing, the alt i got was exactly like the stock one as far as i know. Please enlighten me, wiring and electrical is defineately not my forte. Thanks a lot!

DaveSmed
04-08-04, 12:40 PM
That sounds like it. The same place you bought the alternator from should be able to get it.

highonchai
04-08-04, 12:47 PM
Ok great, i found it at autozone WELLS VOLTAGE REGULATOR $10.99, sound about right?

DaveSmed
04-08-04, 01:01 PM
Sounds good.

MMNineInchNails
04-08-04, 04:12 PM
Ok great, i found it at autozone WELLS VOLTAGE REGULATOR $10.99, sound about right?

don't buy a new one yet, take it in and get it tested. If it works fine, what's the point of buying another one?

highonchai
04-09-04, 07:23 PM
Yep, was planning on it. Thanks!

highonchai
09-07-04, 03:24 PM
Ok, so i just got around to trying to solve this problem. I bought a new battery a while back and a new starter yesterday, Ive got it running and everything. But the 'GEN' light is still on. I just took the voltage regulator in and had it tested at auto zone, it was fine. I checked all the connections to the alternator which is brand new and has been tested since i bought it. but still im getting no juice from the alternator. With the car running i disconnected the negative terminal on the battery and it stalls out, but the alternator should keep the car running correct? Im at a loss here guys. Any other suggestions?? maybe i should just buy a new regulator, theyre only 10 bucks. Thanks for any helpful suggestions you have!

Bang!Bang!
05-28-07, 10:59 AM
im having this same problem with my '71 472 Coupe. does the gen light surge? mine does and all the lighting in the car surges along with it. make sure you but the correct voltage regulator. buy an external, there are many internal regulators listed for my car as well and are of no use. im not too sure if the regulators are adjustable. my GM service manual says the car should have amn adjustment screw on the voltage regualtor when you remove the water proof cover but the one that was on my car was not adjustable and im thinking thats what may be the problem. there may not be enought voltage passing through the regulator. let me know if you solve it, it may help me solve my problem too.

thanks,
-Dan

cadillacmike68
05-28-07, 09:58 PM
The voltage regulator should NOT be on the firewall Is sounds liket the right part but it is supposed to be mounted on the right fenderwell (wheelwell). There should be FOUR terminals peeking out from the bottom. The original units were all black, not silver/ chromed.

DaveSmed
06-01-07, 02:59 PM
Unless the vehicle in question is a show queen, there's almost NO reason to not upgrade the alt to a newer one when the old one croaks. It's bolt in, simple, and cheaper to boot.

Shark2th
06-06-07, 05:39 PM
My generator light went on while the key is out. Tested my generator and it's not recharging the battery at all. On my 71, while attempting to replace the alternator, I found the bolt on the bottom rams up against the fax coweling when I try to get it out. The bolt still has another 1/2 an inch or more to go before it will completely extract. Does one need to bore a hole in the fan coweling to remove that bolt, or is there a technique that I'm missing? The coweling is sheet metal and part of the over all frame of the car.

Bang!Bang!
06-07-07, 04:20 PM
dude, i just fixed my problem and it sounded exactly like yours. the fuse looked fine and when i pulled it and had a real close look i found it to be no good and the wrong amp fuse. your gauges/trans fuse should be a 10 amp not a 6.5 or a 7. try and tell me if it works for you!

-Dan

jayoldschool
06-12-07, 04:11 PM
I had the same problem with my 65 Impala one spring after I boosted it. The Gen light was on. Swapped out the voltage regulator (15 bucks, in stock), and it has been fine since then. For ten bucks, give it a try!

kiowamec
06-13-07, 10:26 AM
I would first check for corroded connectors. Then look at the wiring diagram to determine what causes the indication and work from there. Additionally, most towns have a starter/alternator shop. They normally are reasonable.

Shark2th
06-14-07, 12:12 PM
Thanks for the replies guys. I checked the fuse and it was working and the proper type. Went to Napa Auto, grabbed a new/rebuilt 80 AMP gen, got past the coweling issue and finally installed the generator last night.
It's tests fine and the Cadillac is purring better than ever.
Appreciate all the assistance folks.

The Ape Man
06-15-07, 07:37 AM
Thanks for the replies guys. I checked the fuse and it was working and the proper type. Went to Napa Auto, grabbed a new/rebuilt 80 AMP gen, got past the coweling issue and finally installed the generator last night.
It's tests fine and the Cadillac is purring better than ever.
Appreciate all the assistance folks.


So for a recap: Taking your alternator to an auto parts store to get it tested isn't going to do much except waste time.

Shark2th
06-27-07, 09:45 PM
If you mean The Ape Man that going to all the work of taking the alternator out and down to a store, just to get it tested is usually a futile effort, I'd agree. I took mine out, went to the store, bought a new/rebuilt unit simply with the decision that after the effort of pulling it out, I refused to install it back in, just to have it fail. I'd much rather simply install a new one since they really aren't all that expensive and come with a warrenty. Mine was long out of warrenty. HA!:)

kiowamec
06-27-07, 11:56 PM
Wish I had the money to replace good parts with new ones.

The Ape Man
06-30-07, 01:02 PM
Alternators should always be checked where they are installed. There are several failures that can make the alternator test OK on the bench but not work in a car. Auto parts stores cannot usually afford to pay someone qualified to properly test an alternator. Someone with that level of knowledge will not normally be selling auto parts. A good test setup for an alternator will cost real money.
Better off going to a good garage where the money has been spent on test equipment and training. Please note the operative word in that sentence.
As far as replacing perfectly good parts with new: How much money will you save when the car has to be towed home? Not everyone has spares and knows how and when to use them. Not everyone has test equipment and the experience to use it properly. Some of us actually use our old cars as daily drivers and 1 day off from work due to a breakdown will cost far more than another alternator. Sometimes it's better just to start over with fresh stuff. The running around and peace of mind lost to a tough problem alone isn't worth the hassle for most people who have a life. Fill out a balance sheet.
Personally, I have not bought a Cadillac alternator even once in 27 years of driving them. I keep spares and I enjoy being thrifty. That is going to change soon as I'm upgrading my electrical system for some mobile radio equipment. Anyone know how to stick a real 200 amp alternator on a 1980 Fleetwood?

kiowamec
07-01-07, 09:48 AM
I’m sorry, I missed the point.
If your worried about old parts breaking down.
Why wouldn’t you just go buy a new car?

Additionally, its only a cost effective option to own an old car if your are capable of performing the maintenance yourself and you are willing to deal with occasional down time due to repairs. In my opinion using shops for repairs is risky at best. You will pay allot of money for their time. You may get charged for repairs not required or not performed. They may cause additional problems while working on your car.

I personally own three old cars, if one breaks down I still have two for back up.

If you’re just going to throw new parts at a car until it works, save your time and just by a new car.