voltage probs at startup..alt belt maybe?

[Hook]

Now I know I've been having intermittent starting probs lately and it's prolly linked to the fact that I need new valve stem seals, but just now I was bringing it in from out in the rain and had the same start up prob (took a couple cranks and a little gas to start it). THIS time, I noticed that the idle was a bit rough and all the lights (dome and park lights) were dim until I revved it a bit.

Now this only happened for about 3 seconds after it started. Could this be a sign of the alternator belt being either too loose or maybe too tight?

[TRDragoon]

damn! i forgot which Corolla you have.....but if it was the one from 98~02, you might wanna replace the Serpantine belt... they get stretch really badly. My guess would be either the belt is loose or your alternator is about to go.

[OEMonkey]

during cranking, the batt. supplies all the electrical power, not the alternator. the batt. provides voltage and is a source of current for starting, lighting and ignition and acts as a stabilizer for the cars electrical system. once the engine is running, the charging system takes over and supplies all the electrical load demands while also recharging the batt. its easy to check your batt., starting, and charging system with a voltmeter. and I agree with a loose belt causing charging probs. but not necessarilly a prob. with the alternator.

[Hook]

TRDragoon: it's an '86 EE80 rolla

yeh OEMonkey, I totally understand what u're saying but the lights dimming only happened for the first 3-4 seconds after the car started. You think maybe it could be the battery causing the initial instability? It's only about 4 months old tho.

When I revved slightly it remedied the prob, that's y I'm thinking it's the belt. *shrugs* Maybe there's some slippage and revving a bit caused it to contact the pulley properly.

The belt's pretty fairly tight right now...can overtightening cause this prob? If so, exactly how tight is the belt supposed to be?

There's a very very slight squeal sometimes on startup when it's really cold out so methinks that's due to to condensation on the belt. PLUS last night when I noticed, it was pretty cold out AND it was raining.

Even if I change the belt, is there something I can do to prevent condensation/slippage like this from happening again?

[OEMonkey]

QUOTE]There's a very very slight squeal sometimes on startup when it's really cold out so methinks that's due to to condensation on the belt. PLUS last night when I noticed, it was pretty cold out AND it was raining.[/QUOTE]

about a month ago, I started my car early in the morning and it was cold and raining and my alt belt was squealing like a little girl for a couple o secs. at the same time I glanced at my voltmeter gauge and it was reading open circuit voltage(12.5v or so) and rose back to a normal 14.5v reading after the belts squealing ran its course. so, if it only happened once, I wouldnt worry about it. like I said before, you can diagnose these things fairly easily with a voltmeter or any kinda dmm. as for belt tightness, measure the belt deflection at its longest span. then press down right in the middle and it should deflect a quarter to a half inch. also check it for cracks and fraying and check that theyre squarely in the grooves of each pulley. other physical and visual checks you could do- battery connections(corrosion), bolts and mountings since the alt. completes its ground through their mounting. they should be clean and tight unless you want high resistance ground. sorry for the novel, hth.

[Hook]

okay cool...thnx man

a bud of mine told me there's a 'belt dressing' that can be applied to increase the coefficient of friction on the belt so that it never squeals and always contacts the pulley properly.

I'm kinda skeptical about applying anything to the belt surface seeing as how most petroleum-based products can really phack up those things and I don't want a broken alt belt at some unholy hour of the morning in gangsta territory (u know what I mean).

Do u know if this is safe to use?

[OEMonkey]

belt dressing would be a temp. fix. just replace the belt if you suspect it. also, dont overtighten it. it'll wear out the alternators bearing.