1995 Rodeo - 3.2l - 6VD1 motor - 250K miles - well maintained.


No doubt I'll have to dig deepr here and have alternator/harmonic balancer checked.

Looking for personal expeience(s) anyone may have had with what I'm about to describe.

I normally nail problems early in my diagnosis, but this one has kicked by butt.


When I turn on a/c, i get a loud intermittent screeching sound. More noticeable after motor has warmed up. Recent repairs include all new a/c, power steering; alt. belt Good tension on all belts. The screech occurred before the belt change and after as well. New a/c idler pulley and new fan clutch also installed. Neither of those changes have helped either

With cold motor and engine idling, VOM shows - 14.10v - 14.15v. At rest for 8 hrs. - battery OCV is about 12.65.

More likely to occur after motor gets warmer.

Now for the stranger part.

Vehicle has been idling for 30 or more mins. Depress window control button(s) on driver side door handle to raise window that's already up. Did this by accident; that's how I discovered this quirk. Now with the button down, the under-the hood scrrech starts and lasts as long as I hold the window control button down. Again, a/c is on.

Screech does not occur if a/c is off.

Staring at front of a/c pulley/clutch, I see no slippage or pulley drop-off/slow-down when the intermittent screeching is going on. A/C blows 42 degree air out vents at idle in the shade.

Local auto. elect. rebuilder I've done business with told me my alt. was shot. The window down-n-up button is not related in anyway to the a/c, so the bad alt. theory has merit.

Another local tech says he's more suspicious of the harmonic balancer. Odd that this screech only occurs with a/c on. I would think the harmonic balancer would be talking to me even with a/c off. Perhaps not.

Opinions appreciated.

I agree with the tech that suggested the problem was the alternator. I would have it load-tested.

Should have updated this sooner.

Turns out the harmonic balancer was coming apart and not really noticeable while eye-balling things with engine idling. Eventually it DID come apart.

I'm experiencing a similar problem on my "new to me" '92 Trooper S. But I don't have A/C. Had a little bit of a squeal when I bought it, so I just figured belts. Under no electrical load on a warm day, everything is fine, no noise. But start up on a cold day and I get a squeal and 12V or less on the gauge. Under electrical load (lights on, heater fan on high, etc) volts drop and squeal returns. Was going to replace the alt belt as it's fraying a bit on the back side, and had an electrical test done at the "zone". Bad alternator regulator and bad battery. There are 2 Isuzus at a local pick your part I can get pieces from '92 Rodeo and a '95 Trooper, both with the SOHC 3.2L. But I cant find a new part # for the damper your talking about, maybe I'm using the wrong wording in my parts search. If you could, could you tell me where you got it, what part number (OEM or replacement part), and how much I might expect to pay. Thanks in advance. P.S. My Trooper is bare bones, only P/B and P/S, no power anything else.

The harmonic balancer is located at the forward end of the crankshaft. While it does occasionally fail, it wouldn't start there with the diagnosis.

I would start with idler pulley. It is a round device on the path of the main belt. It basically is a pulley with bearings. I am not sure on the 3.2, but it usually is spring loaded and maintains the tension on the belt.

Thanks Jim, that will be on one of the last places on the list for sure. Thursday I'm putting on a new alternator belt and then I'm going to a different parts store (Pep Boys or O'Reilly) and have the Alt and Batt checked again. Luckily I have a pick your part near by with a '92 Rodeo and a '95 Trooper that I can salvage parts from. I like to do as much as I can my self, I have space and what tools I don't have, they loan out at most parts stores. but for me time is a factor. The only reason I go to shops to get (some) work done is that they are just quicker. With the pulleys, there are 2 mounted on the engine, an upper and a lower, the upper seems to be where the noise is coming from as opposed to the alternator or the lower pulley. So my steps are this so far. Replace the alternator belt and ensure tension and alignment and check for the squeal. Squeal or not have the battery and alternator checked at a different parts store. If need be (or not) go to the pick your part near me and pull the alternator, and any other parts I think I might need (and can afford to pull) in the repair / upgrading of the electrical system. I figure if I have to repair or replace, I might as well upgrade some things so I don't have to later. Any helpful hints are greatly appreciated, thanks.

Have you located the idler/adjuster?

Refresh me, does the 3.2 have a serpentine belt? If it does, then it does have an idler/adjuster. If so, then it takes a breaker bar (or a LARGE set of arms). There is a bolt on the forward side of the idler. With a breaker bar and socket, turn the bolt counter clockwise. That will release the pressure of the belt.

Old school V-belts. One for the P/S pump and one for the alternator. Water pump is run off the toothed cam belt.