New Alternator Woes.

Hi People,

My name is Chris and I am new to the club but not at all new to 95-99 Rivieras.
I will introduce myself more on the New members section but I really nneed to ask some advice on this topic.

I was on my original alternator for my 1997 Riviera when teh bearing started to wear out about ...geez.. 6 months ago, It lasted untill 3 days ago when i heard a new, but oddly quieter gringing noise and then the subsequent battery light.

Well, I made it to work that day but had to leave the car at my job's parking lot. My buddy picked me up and next day and we went alternator shipping. Well, Guess what? I went to Discount,-Advance Auto Parts, Autozone, and Napa and None of them had an alternator in stock. Finally ordered a premium one at napa which wasnt going to be available for 2 days. It's actually a 150 amp vs. 140 and comes with 5 years roadside asistance! So i had to get rides to work and leave my poor Rivi out there for 3 days! Anyhow, Tonight was fun ( right..) My buddy and I put on the new alternator in teh parking lot which took 2 1/2 hours because one of the bolts was on a super long stub and we did not have deep sockets ( which you need). Soo.. Had to follow another friend that was watching us work to his house and borrow his tools.

To make a long story short, I start the engine and everything is fine ( Oh, by the way I have a failry new 1 year old battery $115!!!) I go to take off and teh belt slips! Dont know what it would do that. The new alternator has a lip on the pulley so the belt is even more secure. So i drive home and I experience less power ( not electrical, my stereo sounded great), but HP..or at least at seems. I shrugged it off as my PCM having to "re-learn" from the batt. being disconnected. Anyhow, I get home and decide to keep it at around 2,000 rpms for about a minute to help charge the battery a lil more. I do one last rev before i shut off teh engien and notice past 3,000 rpm's the lights were slightly flickering! grrrr It was so slight and most peopel would say " dont even worry about it" but i am worrying aboit it because my previous setup did not do this at ANY rpm. So i rev and rev and throughout certin parts of the band, my lights arent as steady as they should be. I should mention I am talking about my interior lights. Then I got paranoid when i ran across a post online that said " newer higher amp alternators generate more power at lower rpm's to compensate" but I thought it was the other way around. Higher Rpm's = more power generated. Anyhow, I really dont care where the peak power is generated; The lights should not even flicker or change brightness what-so-ever during any reving. Can you sense my frustration! lol this damn alternator was $150 PLUS $70 core charge. Now everything was connected exactly how it was prevoius. I just dont want to go back to napa for them to say " maybe you have a bad whatever-the-hell" when everything was just FIne with my old alternator before it died. I was thinking grounds, connections and the like but everything is how it was. the only differece is this one is new, its shinnier ( lol) and the nut the holds the ground is a new one. everything else is the same. Is is it possible that the computer is set for just up to 140amps? and adding 10 more messes it up? I know that makes no sense but sometimes certin GM specfic cars have codes built in that limits weird crap like that. ( I know from experience) Then why would NAPA have TWO 150 Amp alternators listed as the replacment for 1997 riv's? anyhow, I just want my lights steady!! Oh More more thing. The second time I started it, for 1.5 seconds, it sounded "stallish" and then it kicked into normal idle. Coulndt be the belt too tight right? we have automatic tensioners. Sounds like a voltage regulation problem or bad ground or....??? but why.. the alternator is brand new and Does work but having this sucky ass problem

Anyhow, HELP!

Sorry for typos. Its 5:17am and been up all night trying to research. would hate to have to go through another alternator install and be without a car for another 3 days!

-Chris Kelley

The 97 does list two alternators.

1) One is stamped with part number 10480204 with a replacement part number of 10463691. This item also works in a 96.

2) The second part number is stamped 10480279 with a replacement part number of 10464077. This item also works in the 98.

Since the 97 had both the supercharged and N/A engine options you might
want to look at item 2 as there was no N/A engine in 98.

On my 95 I was able to correct the light flicker problem by tightening
the ground cable connected to the battery.

Yeah, I read somewhere that the 98' had an upgraded alaternator so I'm glad i got the higherout put one but still having this problem. Well, had the alternator tested today and the battery tested 2 days ago. Both check out fine..... but the guy doing the alternator test had trouble with the machine. He said it ws hard to get a positive connection with that little terminal we have in the front. He had to restart it 5 times. Im not sure how reliable that test was now that I think back on it. He said it is putting out 143 amps @ 2000 rpm's. Its a 150 amp alternator and I hadn't driven much before I got there so It wasn't that hot. That's not too much of a concern as the stock was 140. So anything above is an added bonus. The ground cable is pretty damn tight so all I can try is untightening it and re-connecting. Should I disconnect the battery again to do this? This is so frustrating. all my terminals appear clean as do my other connections. of course people said " Oh, thats normal sometimes" Well, no its not because my old one did not do it and this is very annoying. Thanks so much for the answers guys. I truely appreciate it.


-Chris

Using a higher amp alternator won't cause the problems you're having. The PCM doesn't calculate amps, only voltage. Having higher amps is like a reserve that is only used when the car's electrical system demands it.

I'm guessing if you check the diameter of the new alternator's pulley closely, it's a little smaller than the older one. This is one way to get higher amps out of a unit. That could cause the slipping problem you're having.

Or it could be the connections. Use a multimeter to check voltage level at different connection points. Back connections should show a voltage drop or an impedance increase (higher ohms).

Best of luck.

You know, you may be right about the smaller diameter pulley. Why would they make it this way if it is a stock replacement? Surely slippage can happen if its smaller so that doesnt make sense. Did the 98's have different size idler pulleys? I will be very disapointed if i have to return this one and do this crap all over again. for 1. its 10 extra amps which I like and 2. its a pain in the ass. The stock one never slipped. If this turns out to be the problem, how can i solve this? Maybe a gator type belt even though the pulley is smaller? This is really annoying. This may not even be the problem but the tech testing the alternator said its fine. very weird. I don't hear any slipping or feel anything when accerating hard. All my connections look fine. I will try the voltmeter test. Like i said eariler, It only happens at around 2500 rpm's and above but then goes back to normal after really high rpm's. My problem is TIME. I use to work on my cars all the time but now my job limits that greatly. The dude at Napa was real cool and said if it takes me a week, a month or 6 months to figure it out and it turns out to be teh alternator, they will just do an even swap. I will get to the bottom of this! Anyone local??? lol

Thanks again!

-Chris

Really sounds like it's slipping. How new is the belt? Maybe it needs replaced. In that case you could go .50" smaller, but also look into bigger idler/tensioner pulleys... this way you can more easily go back to the stock unit if you need to.

if you want some help just let me know, i've got tools and plenty of room in front of my apt.

Its really frustrating that i woudl have to get a smaller belt and or different sized pulleys ( just bought new pulleys) for a part that is suppose to be a stock replacment. Grrr. I'll let you know how things come along. Thanks so much AA!

Mr, Riviera, What city are you in again?

-Chris

o-town

If you do figure out that the pulley is smaller (and belt is too long) you could always put a larger idler pulley in to make up for it, and that way keep the stock belt size (to avoid confusion in the future).

Lights flickering to me could indicate either a) bad voltage regulator (inside the alternator) or b) poor connection/bad ground. You should remove the battery cables, clean with a wire brush and reconnect. Also make sure the alternator positive is cleaned and roughed up, and the grounding bolts (even though it's bolted to the engine). I've seen corrosion around all of those bolts before.


Hope this helps...
-Derek

If your acc'y belt is indeed slack, try replacing the left hand #3 pulley with dayco part# 89006, a 3.5" smooth metal unit.


Disregard part# 89007, that is stock 3".

Thanks so much guys. All connections seem to be fine. I will figure something out. Am going to install new pulleys soon anyways. I already bought them prior to this. All i was saying is that I do not understand an auto parts store listing an item as a direct factory replacment when the size of teh pulley is different? why would someone that has to replace thier alternator also have to buy a new part to compensate for the new parts' size difference. You know, tonight the lighst were fine. really weird. Oh well. I will figure it out and let you guys know when all in well. Thanks again!!

-Chris
ps: Mr. Riviera. I think we communicated through email a quick a whiel back before I knew about this forum. I think I still have the emails in my saved box..lol

yes we did, back when regalgs was the spot for riv owners