Battery, fanbelt, or alternator - which is the problem?
I got a '89 350 5.7L T/A and has 120,000 miles - I live in Boston and temps are
down in 8 - 20 degrees overnite. Car sits out all nite too.
Soooo it's real real cold nite & most of days - for past 2 weeks.
I take good care of it & original owner.

My dash VOLT guage started (especially at nite with lights on and heater running) to start dipping below 13 reading to the 9-10 mark area.

But when I shut off the lites and the rev engine and RPM go up
the needle goes back up to around normal area of 13.
This goes on continously now especcially during nite driving.

Two nites ago, I started hearing a low, whining, whirring constant noise (not too loud). Could this be the windings inside the Alternator ?

Oh yehhh... My fan belt is kinda old and I have sprayed some belt dressing & I know/think it has been slipping especially earl morning start ups it make on & off again screeching noise then goes away once engine gets warmed up.

PLUS... I checked the voltage of battery bot with engine off and while running with a good voltmeter.
Battery seems ok : Engine OFF = 12.5 - 13
Engine ON = 14.5 or so

Questions:
1. If belt is screeching a little at startup could this prevent the ALTernator from charging the battery properly and /or not giving the car and dash VOLT guage the right amounts of voltage.

2. Should I first just try cheapest things like:
a. replace the battery
b. replace the fan(timing) belt (I know they're expensive - like over $100 - 125, right?
c. replace the ALternator ?

3. Is there a way or where around the Alternator can I sheck the
voltage outputs wires with car running with my voltmeter ?

3a.. Is this dangerous & possible to get a bad shock by checking the running alternator ??

Thanks for all the help - I hope...
BLUETA89 - trying to make iot thru another BADasssss freezn' winter !

 

If the engine starts without complaint on a cold morning after sitting out all night, doesn't sound like a problem with the battery.

The running voltage is best checked under load. Start the car, turn on the lights, load the electrical system every way you can think - AC, fan on high, stereo on, etc. Then check the voltage at the battery.

Or, you can remove the alternator and take it to your local friendly parts store with a testing machine and they will check the voltage and amperage output under load.

A whinning sound is normal for an alternator under load. So, that doesn't sound particularly alarming.

The belt should be replaced if it is old, stretched, or cracked (easy to check for cracks at a pulley that rides on the back side of the belt). Check the tensioner to make sure it is putting on sufficient tension.

 

i'd do as he suggested and get the alt checked (for free) at a parts store. my own experiences with alt's is that they will make that strange noise if they're on their way out. but your batt sounds like it's healthy - for now. if the alt is going bad, then it's not going to charge your batt eventually. you can recharge that, though, but you're probably looking at a new alt and i would change the belt, too. i don't know why you would think they cost that much (belt) but i think a serpentine belt runs around 45 or so, can't remember, so a single belt ain't that much. fan belts have nothing to do with timing belts or chains, btw.

KAM

 

Five7 has it. The belt is easy. The serpentine usually isn't prone to slipping, so I'm going to bet the alt may be going out, BUT, stranger things have happened. I'd get the belt and while there get the alt. checked.

 

Pls explain simply ( and clear things up) for me...
I'm making my BEST guess.... I'm no mechanic or eletrician - for sure!


The battery is 12 volts DC or so +/- 1 volts usually and the
alternator turns via the gas engine and the main purpose
(or only one) for the alternator is to continuously keep the
battery charged up to its 12 volts. Is this all correct ?

The electricity for the car is produced by the Alternator which then converts it into DC and it then supplies the battery with
a "smooth" 12 volts or so Direct Current (DC) ??? Is this correct?
And then the battery and its positive cable somehow provides the 12 volts DC power to all the cars' electrical equipment?

( oh yehh - I forgot there is the Coil thingy too - right).

The battery of 12 volts DC supplies: the headlights, heater, wipers, radio, all lights (brake lights, etc), horn, interior fan blower (heat or a/c) all with Direct current power.
Is this correct ??

Soooo... when I'm driving (expecially) at nite in bad freezing weather with all the above electrical devices loading down electrical system -
The battery gets used more (maybe way more) than when
driving on a nice spring warm day. Right?

1. Does the Alternator have some sort of intelligent automatic
different speeds or something? to adjust for the different electrical loads the battery is requiring to keep it charged during
completely different driving conditions ?

1a... Or does the Alternator just simply work (dumbly) by ALWAYS trying to keep a steady 12-14 volts output into the battery???

PLEASE help explain how this all works so I can understand it
better.


2. . Is there a way or where around the Alternator can I check the
voltage outputs wires with car running with my voltmeter ?

2a.. Is this dangerous & possible to get a bad shock by checking the running alternator ??


THANKS

 

The battery's main purpose in life is to start the car. Yes, it also powers the interior light(s) so you can see when you get into the car after dark, and runs the stereo when you're parked at Lover's Leap, but mainly it's there to start the engine.

After the engine is started, the power to operate the electrical devices is the job of the alternator. It also recharges whatever was used out of the battery to start the engine. It has an internal "regulator" that keeps the voltage output fairly constant regardless of engine speed. At idle, it is possible for the voltage to drop below that if the load on the system is high (headlight, AC, brake lights, stereo, etc.), but it should still be at or above the basic battery voltage if the alternator is healthy.

The alternator needs to be tested under load. The best way to do that is with a tester designed to do that. There are places like Sears that will disconnect the battery cable and hook it to their tester to perform that test, or most parts stores have a machine that will test the alternator by itself. Take the car to Sears, they'll test the battery and alternator for free.

 

Thanks, Five7kid... Guess I was screwed up pretty bad about how the battery and alternator work.
I guess the Alternator is alot smarter and sophisticated than I thought.

Yesterday, took my TA to local TA mechanic (he owns 3 himself and done work on mine before - he does pretty good work and have lots confidence in him).... Plus I let him "use" my TA car 2-3 times to check/repair his electrical wiring on his '87 TA (no charge by me) and he got his car back up & running - thanks to me...

He said pretty quick from the
whining/whirring sound(noise) and after we turned everything on
(heat, lites, fans, radio, etc) and saw the Volts dropping below
13 mark while idling.... that I needed an ALTERNATOR. He put on a battery tester gun/gauge to see volts from battery under load.
He says my serpentine belt looks ok - no cracks.

SO he says... "$250 - I do it for you tomorrow, ok"
That is $185 for alternator and $65 = his time/labor.

I called 2 GM dealers and a NAPA parts store:
- both GM dealers NOT have Alternator in stock & must order
& would take maybe 2 days or a week to get (w/Xmas here).
Both dealers said about $100 for the part.

The NAPA store had an '89 350 engine 105 amp Alternator
in stock for $100 - with 1 yr guarantee and if return old one get $4 off.

QUESTION:
1. Do you think (anybody) that $250 is kinda too high to replace an alternator ($185 parts + $65 labor) ????
Am I getting ripped like a sucker?

2. If I bought alternator from NAPA myself $100 - how hard/difficult is it to remove and replace alternator MYSELF ?
I am novice DIY guy & would need to buy/rent some tools from autozone ???

3. Main question - how do you first start to get the tension off the serpentine belt and get the belt out of there to start removing the bolts for the alternator ?
3a. DO you need a special toool to do this ?
3aaa. Oh yeh... HOw much muscle power/ strength does it take?
(I don't got much)

3b. How many bolts do you actually need to remove first before getting the alternator off the car?

THANKS!

 

1. I think that is high for replacing an Alternator, you found alts. at stores for less than he is saying. $65 for labor! What is his hourly rate? $250? For a professional Mechanic I'd say 15 minutes of work.

2. It is not hard to replace, you can do it! If you have no tools at all just get a basic set of 3/8" drive sockets (6 point) and a ratchet, and a shop manual.

3. First disconnect the battery negative terminal. The positive terminal goes straight to the alternator and if you touch anything with the cable with the battery still hooked up it will arc real bad. Could ruin the cable. To get the belt off there is a tensioner that you need to hold out of the way to get the belt off. Then disconnect the positive cable and the engine harness. Then take the bolts out of the alternator.

I highly encourage everyone to do as much work on their cars as they are comfortable doing. Especially the easy stuff. I do all my own repairs on my cars, except tires and alignment, I don't have the equipment for those.

Hope this helps.

Bruce

 

That kind of operation is explained perfectly in a shop manual like Haynes or Chiltons (have they been combined yet?). Spend $15 on one of those first, then go get the rebuilt alternator from NAPA and replace it.

 

and autozone pricing:

ALTERNATOR for a
1989 PONTIAC TRANS AM
DURALAST
105 AMP DL1367-6-11 LLT $20.00c $84.99
PREMIUM QUALITY REMAN, SOME NEW COMPONENTS

VALUCRAFT
105 AMP 1367-6-11 1 YR $30.00c $74.99
PREMIUM QUALITY REMAN, SOME NEW COMPONENTS

GOLD-DURALAST
105 AMP DLG1367-6-11 LLT $30.00c $119.99
DESIGNED FOR MAXIMUM DURABILITY 100 % NEW


so you are looking at $100 total with book and part.

 

Saturday- went back to my "man" & he got a "Worldwinner" alternator at the local parts supplier and took out & replaced my
alternator in about 30 minutes (no troubles at all).

I got a cut-rate of $187 ($50 labor + rest parts & 5% tax).
(Instead of the $250 he originally wanted to charge me)
Ohh yehh... I bought the 2 mechanics XLrg DunkinDonuts coffee
to get them started... Real bargain huh... I just did not have time or tools to do myself and was trusting my "man" to do it right.

Soooo I thought I was pretty happpy until I got home about 1 hour later and TA was warmed up 100%.

((I tested the Volts dashboard guage after mechanic installed it and car started up super-quick on first try, and volt guage went to 3 marks past 13 as I've always seen as normal and good for "my" car).... I also put it under some load with lites, heater, radio, & backwindow defroster ... but car was still cool and high RPM & oh yeh in Park not Drive.... It looked goood (I thought)

After getting home and warmed up and while driving & I tested it 3-5 times by loading every single electrical thing:
- High beam lites + radio blasting + heater with full fans blowing + rearwindow defrost (this is the HUGEST electrical load on car!)
+ I ran both power windows up & down to use up more electricity... plus with foot on & off Brakes like crawling in snarled traffic jam.
Big difference is when car is in gear in Drive versus in Park when RPM are alittle higher. Volts drop at daashboard guauge especially when in Drive with foot on brakes.
(Brake lights and brakes pull a big load of electricity I found)

The volts guage just kept dropping below 13 then to almost the start of red line area to like 9.5 -10 or so...

This re-manuf or rebuilt "Worldwinner" alternator was almost worse than mine that was taken out.

Sooo I tested my battery at home with my handheld voltmeter and the needle pegged on 14.5 for the battery (w/ engine off and about 13.5 with engine on and fully loaded down).

BUT.... as I tested my battery at the NEG & POS posts with my voltmeter ... the car's dash guage volt needle was showing way way under 13 volts.... like before around 9-10. It slowly ket dropping from 13-14 to almost around 9-10.

Soooo... THIS means that the dash guage volts is not measuring the battery like I was doing by hand at the posts.


Questions:
1. WHat or How or Where does the dash board guage get its volts Input from cause it's obviously not directly from the battery ????
( I proved this to myself by using my own voltmeter)


2.. Could I have maybe just gotten a "bad" alternator or a lemon ?

3. Does the '89 350 TA have a voltage regulator somewhere
that controls the voltage output of the alternator ?
Or is this some little component built into the guts of the altternator ???

4. Can I get the voltage regulator replaced or repaired if there is one ??? Seems like after all this that the alternator is not really the problem.

5. Anybody hear of "Worldwinner" alternators ??
I saw the box and single paper it came in from the part supplier to the gas station.
OH yehhh mechanic says it comes with ONE year warranty.
-------

I did check with 2 GM dealers and both said they would have had to order the ALternator and be about a week.
The service dept quoted me (get this ---) $300 -$350 to replace my alternator !!!!!

I phoned my local Autozone and they seemed to have best price like someone said here: $86 for a rebuilt Alternator (if I returned the old one - $20 core charge) and it had a Lifetime warranty.

Napa had one for $99 with a 1 year warranty.

And I checked with local Sears and they can test charging system
BUT it ain't FREE (like someone said before).
Cost is $13.99 for them to test & check. (That's not bad & may do that).

As soon as this PIA snowstorm subsides I'm going back to my mechanic and complain and get him:
A. Get me another ALternator (maybe this is a lemon) or
B. Get back my original one and have him put it back in and get my $187 back and try go do it myself or something.

ANYBODY got some ideas or suggestions PLEASE!
What could be causing the voltage dropping at the dashboard guage Volts but (sa I said above) the Voltage at battery posts are holding VERY steady and good at 12.5 -13.5 always.

THANKS

 

Autozone and Advance Auto will test for free.

 

Where exactly in MA are you?

 

I'm running a rather sophisticated stereo system in my car and I noticed (once again) that my alternator is whining. The last time I replaced it, I had the option of spending a little more money and get a higher amperage alternator that would have been able to support the stereo, but I opted for a regular rebuilt one and now once again, I'm in need of a replacement.

The small problem I have is that I keep hearing about all these higher amped alternators not performing at their peak and was wondering what kind I should be getting. I figured I'd get the most powerfull one I've seen, which I think is 160amps. Does it make a difference? Is it possible for anything to be damaged running at an extremely higher amperage?

 

Did you ever figure out why the dash voltage guage wasn't reading the same voltage that was at the battery? I'm having a similar problem.

 

No, but I think I'll go ask someone at the parts store to see. Right now it's either the alternator or a dying battery. If anyone can tell me it's not one or the other, then I have my answer.

 

You were having problems with your dash voltmeter, too? My question was for blueta89.
The only consideration for a higher amp alternator is whether or not the stock wiring is big enough - otherwise you could burn up the wire, which is never a good thing The alternator should specify what is needed.
Typically if the alternator is bad, you can hear it whine pretty loud when you accelerate.