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.