Alternator Problems for 93 Allante

[Rsrtelecom]

I have a '93 Allante with 50,000 miles. The local Cadillac dealer has replaced the alternator 4 times in the last year and now the car is showing signs that it is time for a 5th. I was told that the dealer can only source replacement alternators from rebuilders now and that they are never sure of the quality. Sounds like a load of bull to me, but I am wondering if anyone else has experienced alternator issues. Is there a possible that something else in the car is causing the alternators to fail so quickly? Other than the alternator failing to charge the battery, the car seems to be fine. Thanks in advance for your thoughts.

[Stealth]

Originally Posted by Rsrtelecom

I have a '93 Allante with 50,000 miles. The local Cadillac dealer has replaced the alternator 4 times in the last year and now the car is showing signs that it is time for a 5th. I was told that the dealer can only source replacement alternators from rebuilders now and that they are never sure of the quality. Sounds like a load of bull to me, but I am wondering if anyone else has experienced alternator issues. Is there a possible that something else in the car is causing the alternators to fail so quickly? Other than the alternator failing to charge the battery, the car seems to be fine. Thanks in advance for your thoughts.

It isnt a load of bull .. it is a serious ongoing problem and has been for years. Print the allantesoruce paragraph below and hand that over to your mechanic, it might help him.

You didnt state if they are doing this under warranty or you are footing the bill for each one or what the sytem is doing that shouldnt be doing.

We have seen that problem in PepBoys alternators for years and the solution has been to stay away from rem units and go DELCO new, even used. DELCO REM units are experiencing the same problems as the PepBoys.

The problem of failing re manufactured units applies to all year Allantes although the writing below only applies to the 1993 models, both the early 93 and the later VJ4 models.

I am not sure that the '93 uses anything unique as compared to the rest of the Cadillac fleet. Your best bet is probably to find a factory OEM unit, even if it is from a salvage yard.

Is your car an early '93 or a late '93 VJ4 model ?

read on ...

Originated by allantesource

We've seen a couple of these problems now, so it's worth passing along some information.

One more comment learned the hard way: The 1993 Allante' alternators are a lot tougher to change than the earlier ones, so always make sure to have the alternator tested before installing it.

A few months back we got an out of the box Delco rebuilt alternator that was completely dead. The car we installed it on was an early 1993, so there was no removable plate underneath. So the radiator had to be pulled twice. That just added insult to injury.

Everything we get from now on will have been tested prior to installation. The recent 1993 Allante' alternator problem involved a battery drain and slightly undercharging alternator when it came in. There was a no charge message showing, but the alternator was putting out something, enough to run the car.

We found it had a 350 milliamp draw that was quite elusive. After exhausting all other ideas, we pulled the regulator plug off the alternator, and were quite surprised when the draw went away.
We put another alternator on the floor under the car, hooked all the wires up, including running a ground wire to the alternator frame. There was no draw.
So we installed the alternator in the car, and rechecked it for a drain after we had started and run it a while. The charging amps which had been about 13.0/ 13.1 when it came in went to 13.9/14.0, which is where we normally see them. So everything seemed fine.
The service electrical system message showing a charging problem was gone, and there was no excessive drain when the car was shut off.
We suspected a problem in the bridge rectifier with the old alternator had been the cause. Then sometime within the next 150 miles the no charge message came back, and subsequently upon testing the battery drain had returned.
Since the alternator had fixed the problem before, we sent another alternator, figuring we had encountered another defective Delco unit.
But this time the drain was present in the new alternator right from the beginning. Changing out the PCM was the next thought, but that had no effect either.

The only other cause we have seen before was the alternator pigtail. It looked fine at the alternator, so we had not gotten into it. But when the conduit and tape were removed about a foot away from the alternator, the wires were found to be melted together. Once the wiring was replaced, the problems were all solved.

Looking back, there's a chicken and the egg question here. Was the problem just a wiring problem all along? Then why was there no drain and proper charging with the first new alternator when it was installed? Was there a problem in the first alternator that caused the wiring problem? Or did it just happen from normal usage?

This was a low mileage car (60K+). The core was long gone so there is no way to find out for sure. Looking ahead, it's a lot easier to repair a pigtail than to replace a '93 alternator. So no matter how good and undisturbed the pigtail looks, it's worth pulling it apart to make sure nothing is compromised if you have a low charging problem and battery drain problem on a '93 Allante'.

.

[roadrunner1]

93 alternator and charging system problems can really be a mess. Mine just spent a month in two different shops. First, there is only one alternator you should be using on a 93 and it's the A.C.Delco 3211131 reman unit. It costs more than other units, has a shorter warranty, but is the ONE recommended by Delco for this application. Delco makes two different ones and the other is a lifetime warranty unit, cost a bit less to be competitive with other reman units, but how many times to you want to play this game is the question. The problem with my 93 was probably where it lived most of it's life, Chicago. For almost all it's previous life, it was a daily driver, in the sun, the rain, the snow and ice. And with that, the salt on the roads. My electrical system was blooming or flaring about three times a second. You could see that in the message panels and at night in all the lights. NO CODES showing. The original alternator was a Bosch unit which may or may not have been the OEM unit according to Delco. Had it not been for failed bearings in the unit, it would probably still be there. The blooming or flaring was caused by two critical issues. Bad grounds throughout the entire car, even under the dash, and something weird going on between the battery temperature sensor in the battery compartment strapped to the cable of the battery. Not all Allantes had that device. The sensor was proven to be fine and ultimately was totally removed from the cable, disconnected from the circuit and all was well once again.

If you have what you think is an alternator problem due to blooming or flaring of the electrics, think Ground Troubles. The service manual talks about a little over a dozen of those, but there are probably about 4 times that many in the car. Any one of them could be bad and many are probably bad. In my 93, almost all of them were corroded and rusted inside and outside the passenger compartment. You will need to go through each one you can find, clean them up completely and put them back together properly. This will take several hours even for the most experienced technician at this sort of work. But, it's essential to fixing the problem. Without good grounds everywhere, your problems will continue through a dozen alternators, because that device is the first we love to blame. First, check the pigtail from the alternator and the grounds relating to that and second check the ground from battery to body in the back of the car behind the passenger. Then keep going and get them all clean. When you think you have them all cleaned up, don't forget to reset the computer following the instructions in your owner's manual.

By the way, it's a really good idea to disconnect the ground cable from the battery before you start playing around with this problem. If you don't and you make a power grounding mistake, you could damage lots of other things electrical on the car and there are several computers on board.

One last thought worth mentioning. These cars are 15 or more years old and a lot of electrical issues begin to come up. Another place to look is all the relay and fuse connections. Wherever exposed connections flow electricity, corrosion can take place. Fuses may look fine, but the fuse connection may be corroded and need to be cleaned. If corrosion has taken place, and I am sure it has on all of them, it could cause the alternator to have to put out more than it should in amperage to jump the gap, and that will burn out components. In my case, with my 93, normal 30 amp output was jumping up to 60 amps to spark the bridge three times a second. Eventually, that will do a lot of damage throughout the entire car. Connections like this, either power or ground, attract moisture and that moisture degrades the connection. Expect it and it won't surprise you when and if you notice a problem.

Good luck and enjoy your car.

[ald42]

I'm wondering if roadrunner 1 could explain how to disc.the temp.sensor and retire the "no charging" message on the dic. thanks.