Squeal when accelerating with heater on

Had Toyota instal a used auto tranny in my 05. After instal I noticed a quiet squeal when taking off from a stop BUT ONLY with the heater on. Any thoughts on why?

 

Was the heater on a defrost setting?

 

Do you drive a manual? If so 5spd or 6spd?

 

He said it is a “used auto”. He had it replaced.

 

On my 2013, say you switch to defrost. A/C automatically kicks in (orange LED). But then, if you switch to a position that doesn't push air through the windshield vents, the A/C stays enabled, and you have to hit the A/C button to disable it. If this is standard behavior and not a fault on my particular vehicle, then I'll wager millions of drivers are running their Toyotas with the A/C comp engaged and they don't even realize it.

 

On most vehicles, the defroster automatically kicks on the AC, but does not give you an indicator. However, it automatically switches off when you change from that setting. But, it should also be noted that your AC compressor will not engage below certain temperatures as a safety measure.

But you're right about Toyota and leaving the AC on sometimes for whatever reason. I have an automatically controlled climate so it may be different for me, but it seems about 50/50 as to whether or not the AC stays engaged.

 

As others have said, if your AC is on (or defroster) then it could be from the AC engaging. See if it happens when it is on normal vent and the AC is off. The AC engages to dry out the air better. Other than that, there's nothing that doesn't turn from the serpentine belt that wouldn't be already turning without the heat on.

 

Ok thanks! It’s on defrost I’ll try taking off with it on vent. I know what you guys are saying about the ac mine doesn’t show the ac is on but doesn’t mean it’s not. I’ll try to have some one watch the clutch when I turn the heat on.

 

Yeah, I did some experimenting with mine and noted that I could turn off the AC when the defroster is running, unlike every other vehicle I've owned. Again, not counting when it is too cold for the AC compressor to work.

 

I used to have an Accord that had a pushbutton A/C clutch enable switch, and nothing could override it, no matter what you set everything else to. IMO that's the way to do it. I wish to hell these manufacturers would stop overcomplicating things and forcing me to search for workarounds so I can run the equipment the way *I* want to run it.

The other thing I wanted to say, re. the belt (or whatever) squeal post-tranny work: I wonder if they spilled ATF on the belt and so now it's slippery, but it needs the A/C compressor load to show the symptom. Eh... just thinking out loud...

 

Spray a little WD-40 on the belt then take it for a drive and see if it still does it. Yes, the belt will slip a little when you first put the WD on there, but it will wear in in short time and temporarily quiet the squeak. That may give you an indication that that's the problem.
I got antifreeze on the belt on my wife's minivan once and could not get rid of that damned squeak until I changed the belt. I tried everything on it. I even duct taped a rag to the end of a stick, put paint thinner on it and held it on all sides of the belt while the van was running. It would fix it for a day or two....
Maybe they got something on the belt when they were changing the transmission.

 

I think I have it figured out. When accelerating the blower motor shifts just slightly and squeals. I can get it to do it by pushing on the blower motor.