squealing and tach not working, please help!

[thedart]

I am driving a 1989 jetta turbo diesel. Last June new alternator was put in, as well as alt, a/c, and pw/s belt.  Bought the car april last year, and was told that the timing belt had just been done.
    A few weeks ago my car started acting like it was having alternator problems.  While driving my heater fan and lights would power up and down, and the car felt like it was surging. As well, at random, the Tach would dip below 1Krpm, i'd hear a short squeal, and the tach would pop back up.
  Because the alternator is new, went out and got a new regulator fo it. And the alt and pw/s belts were tightened (but not a/c, too hard to get too).  The lights and fan surging has stopped but the squealing has gotten worse.  From the short squeal and tach drop, the time it would drop got longer and longer.
  Now, this is what it has been doing.  I start my car, let it warm up, tach will be at just above 1k, and my batt light stays on, until i give it a bit of juice, light goes out, and the tach drops below 1k.  I pull out of my drive way, and the squeal will start, go away when i shift, and then come back.  The squealing will follow me for about 2 blocks, or until i can 'hear' my engine rev up to about 3k's.  Sometimes when i turn a corner, the squeal will come back again for another block or two.  When i'm driving around town, the tach will stay down, but on a recent 20 min drive, the tach randomly started working again.  The squeal is there everytime i park, shut off my vehicle, and restart.  While i am driving, the tach is always down, wether there is squealing or not.
  A few weeks ago before i put the new regulator in, we tested the voltage drop across the battery, as it says to in the repair manual, and it the results showed that my alt was charging my battery properly.  But this week i have noticed that my car is needing a little bit more juice for it to start.  As well yesterday i was at school, and accidentaly left my lights on for a couple hours, which in the past hasn't made a difference, but this time i couldn't start my car, so i think that my battery isn't charging properly.
  my questions are: because we didn't tighten the a/c belt along with the others, is that making a difference? Is my alternator faulty, and should i warrantee it? if not these, what else could it be??  thanks

[burn_your_money]

What's happening is the alternator is requiring more torque to turn then the belts are providing. You need to tighten or replace the belts.

As a test, when you are out driving, turn on the high beams, rear defrost and the blower motor on high and you'll probably see your tach drop back down and the belt squealing.

Same thing happens when you make a turn, the power steering pump comes under pressure (it's an open loop system so it always has constant flow) and the belts start slipping again. This shouldn't really effect the alternator and tach though, because they are driven by different pulleys.

I'm not positive but if your waterpump pulley isn't freewheeling it may cause the belt slippage that you are experiencing.

[Vincent Waldon]

Unfortunately the idiot light won't warn you about *low* charging output... just *no* alternator output.  Loose belt = low output = low tach reading = trouble starting eventually.

For once it all makes sense !!



Vince

[jtanguay]

i have to re-tighten my alternator belt after about 500 km's of driving or so... turn on defrost & blower to max and the belt will squeal.  turn it off and it goes away... just high load.  the tensioning system with a/c is kinda crap...

[Possum79]

I also must add my two cents to say that if you drain your battery once it will never again be the same. Sulfated battery supposedly. Plates build up junk on them and they wont charge right until you remove the sulfates from the plates. Ive never used a de-sulfate-r but we had to make one in school and mine never worked. They supposedly work.

if im wrong tell me so i stop talking about crap that doesnt work.

[burn_your_money]

I think the sulfating only happens if it is left in the uncharged state for extended periods of time. Lead-acid batteries need to be kept at full charge for maximum performance.

I'm not a battery expert though

[akrallysport]

Unfortunately the idiot light won't warn you about *low* charging output... just *no* alternator output.

Oddly enough my batt warning light has never come on the three times that the ring terminal has broken off the wire from the alternator. Wondering if I should hook up an ammeter to alert me of future problems.  :roll:

[burnt_servo]

check your ac belt  , it takes all the load of the ac , then on top of that , all the load of the charging system .

to top it off , it is possibly the most poorly designed setup i've ever seen on any car .

you need to stay on top of it , making sure the belts are snug enough to not slip , but not so tight that they wear out the #1 main bearing ( you'd be surpised  how many cars have this bearing wore out ) .

[Vincent Waldon]

Unfortunately the idiot light won't warn you about *low* charging output... just *no* alternator output.

Oddly enough my batt warning light has never come on the three times that the ring terminal has broken off the wire from the alternator. Wondering if I should hook up an ammeter to alert me of future problems.  :roll:

Yup... it's called the idiot light because it's an idiot...  a voltmeter is one of the gauges I always put in my cars.

[jtanguay]

yea i have a voltmeter gauge somewhere... i'm kinda lazy to install it though  :roll:  maybe this summer?  :lol:

the tensioning system makes me want to convert to serpentine, but i wonder if the 1.9 crank issue would then trickle over to the 1.6 engine??? and plus the fact that it would be more money than its worth.

[jimfoo]

I also must add my two cents to say that if you drain your battery once it will never again be the same. Sulfated battery supposedly. Plates build up junk on them and they wont charge right until you remove the sulfates from the plates. Ive never used a de-sulfate-r but we had to make one in school and mine never worked. They supposedly work.

if im wrong tell me so i stop talking about crap that doesnt work.

Maybe it makes a difference because they were older batteries, but I've almost always had poorer performance once a battery totally discharges, even if for a short (no pun intended ) time. The exception was with an Optima battery, although it eventually bit it after a longer discharged period.

[somolovitch3]

I have found that a volt meter is easier to install and read than an amp meter.

13 to 14 volts - system should be charging

Under 12 volts - battery is discharging