: weak alternator

09-26-06, 11:18 PM
i recently took my 2000 catera 2 auto zone for a battery test. i have a new battery but it doesnt seem to emmit much power the needle is always low on the meter. the guy said my alternator is going bad. how much does it cost to repair? could it be responsible for my cluster lights not wrking and my radio and sunroof having a mind of their own and working when they want?

09-27-06, 08:12 AM
I don't know if this helps, but let me tell you about my experience which still baffles me.

Sunroof would open and close all by itself.
Radio would work only in Acc mode, not when car was running.

Took it to the dealer. Replaced (I think 2) auxillary water pumps and the fuse. Replaced the sunroof actuator.

Problems are gone. I don't know which one fixed the radio, but I think it was caused by the faulty pump somehow. Maybe it is tied into the ignition switch circuit somehow. Thank god for extended warranty cause it wasn't cheap, but I think both are fairly easy to do yourself, but the parts are expensive.

Good luck.

09-27-06, 08:14 AM
Hi Absar. Once again it appears a visit by you to a good auto electric shop might be something to consider. With luck you could kill two birds with one stone.

It is unlikely your cluster lights problem is related to a charging problem. Alternators are just that: they produce alternating current. Since your battery needs DC, there are diodes built into the alternator to rectify the AC, yielding what you need. Sometimes these diodes open or short.

Also it's possible your alternator could have developed a bad winding. I hope not because that most likely will mean a new alternator for you. Your dilemma could be as simple as a corroded connection, something which might be difficult to locate but very inexpensive to put right.

But again, you need the help of a shop skilled in diagnosis of such things. Also you need a place able to run the essential tests.

However let me agree with a bit of your own thinking. If it were my car I would go after the charging system FIRST, and try to get that fixed. While the charging system is unlikely to be related to your cluster light dilemma, anything is possible. And fixing the charging system first will be not more expensive.

Good luck to you. I hope you are able to get to the bottom of these annoying problems and begin once again to get full enjoyment from driving your Catera.:thumbsup:

09-27-06, 08:22 AM
Oh, by the way, my voltage guague is always very low on the scale too, but it was always that way. I was told by the dealer that as long as it is not in the red which is at the very bottom it's OK. I had the output checked, and it was around 13v at idle. I think (but don't know for sure) that the 1st line near the red must be 12v, so even at the next thick line would be 13v. That said, the car eats up batteries every 2 years.

09-27-06, 11:44 AM
Took it to the dealer. Replaced (I think 2) auxillary water pumps and the fuse. Replaced the sunroof actuator.

Your dealer was a scammer, the Catera has no auxilary water pumps! Nor have I ever heard of a any car that does!

09-27-06, 12:34 PM
All Caddy dealers are scammers, however, the aux water pump is real, and it was blowing fuses. I checked in the service manual. It's purpose is to increase water flow at low idle.

09-27-06, 01:40 PM
Before touching the alternator - ($950 + install in Can), I would check the ends of the starter cable. I had what appeared to be a bad alternator as the battery guage almost touched bottom when I had A/C and headlights on and strange things were happening with the electrics. Caddy said it was the alternator!!. I dug about and found that the battery end of the starter cable had seriously eroded - lots of green stuff and broken copper strands - it was hard to see at first but eventually even the protective cover broke down with the additional heat caused by extra resistance.
Solution for me was - cut 2" off the cable and put on a new connector to a side terminal battery (wouldn't reach the top of the battery anymore) - lasted for a year or so. Next, I just cut the existing cable near where it turns down to the alternator - and ran a new #2 cable from the Starter terminal to the battery. Works just great now.

09-27-06, 02:11 PM
I had a problem with my voltage on my 2000, when the car was running, the alternator was putting out about 12.20 volts. I thought it was a bad alternator, but it turned out that it was just the power wire leading from the alternator to the battery. Apperently the wire is undersized for the vehicle. When i checked my wire, the originally red wire had turned white from the heat, and had burnd through in some places. Its an easy fix. Just lift the car with a jack on the front passenger side. Go under the vehicle to where the alternator is and disconnect the output to the battery. Run a new wire (is used 4 Gauge), from the alternator to the battery. Split loom, and zip tie it as far away from any heat source as you can. My voltage went from about 12, to over 14. :thumbsup:

09-27-06, 07:37 PM
All Caddy dealers are scammers, however, the aux water pump is real, and it was blowing fuses. I checked in the service manual. It's purpose is to increase water flow at low idle.

I just found it, the tech manual says it's for the heater. Interesting, first time I've heard of this.

09-27-06, 08:41 PM
I checked, and there are actually two aux water pumps. One boosts flow to the heater core. The other flows water through the radiator when the motor is not running, along with the low speed fan until water cools down.
Back to the original post. The blown aux pump affected the radio and the heated seats. The radio would only work in acc mode, the seats didn't work at all. Replacing the pumps and blown fuse, solved both problems. I guess the circuit was connected somehow.
I guess the dealer got away with replacing the bad one and the good one. The warantee company paid.
Good luck

05-05-07, 02:15 PM
I just wanted to reply to / thank the person that brought up the bad battery cable. I had what I thought was a bad alternator. After reading this post, I measured the voltage drop between the battery and 1/2" from the battery on the starter/alternator cable. I had 1.6v plus drop. I did bought a 60" battery cable and paralleled it with the original cable. What took a bunch of time was dressing the cable along the route of original one. Once again, thank you very much. BTW the car is a 2000 Catera.

05-05-07, 03:37 PM
No problem, I guess it must be a common problem on the 2000. I was having voltage problems for months, and was very close to dropping $1000 to have my alternator replaced. We all know the Catera is a wallet eater, so Anyway i can help save a fellow Catera owner some money i will.

05-06-07, 09:42 AM
If you ever do need a new alternator get one at autozone or advanced auto parts for about 400 and have it installed at a local autoshop such as tuffy i did it and paid about 450 for everything oh and heres the best part comes with warranty had a problem with it (bad bearing)and it was replaced with a new one 6 months later since then no problems Its a 1,000 dollar charge at dealer for a new alt