Coreadrin

Newb here. My mechanic and I are scratching our heads on this one and I thought to see if anyone has come across this before.

The issue is with the A/C. It hasn't worked at all for a couple of years but I haven't driven it much and decided not to bother with it until this summer (heat waves!) when I am driving it more.

The compressor was done, so my mechanic swapped in a new compressor without issue and charged it, as well as my alternator at the same time, because it was pushing a little bit too high of voltage and wearing out.

Once this swap was completed, if you hit the AC button, the fan power on on for less than half a second, then cuts out (AC light turns off as well). The entire system including the fan and everything on and off. It then turns on after a second, runs for less than half a second, and cuts off again, and will just keep doing this indefinitely. We tested the relay and it is fine. We were wondering if it is the speed sensor on the compressor causing issue, but it is getting power for like a tenth of a second (basically the voltage light on meter blinks and then off when the system turns on and off inside), so I don't think the speed sensor would even have time to start sending any kind of a reading out at all.

Anybody have this weird happening that could fire over a suggestion?

This is a 92 SC400 1UZFE with automatic transmission. Basically stock everything.

RudysSC

Sounds like either there's an issue with the new compressor or that perhaps the system is over or under charged. I'd start with a recharge and see how it goes! Be sure to use a legitimate well maintained AC machine as an incorrect charge can cause all kinds of issues!

Ali SC3

iTrader: (10)

you should change the drier at the same time as installing a new compressor, or it will likely ruin your new compressor.
you could also be either too low on pressure, or too high on pressure, there is a safety switch in the system.

Coreadrin

Sorry, that's a history I forgot to include.

We replaced the heater controls with a new one because the LCD on the old one was half burned out and we couldn't make out the codes, and at the same time we replaced the compressor with a certified reman. It was doing that and we thought it might be the compressor, so it was replaced under warranty with another. The only code coming up is the code 21 solar sensor circuit. My understanding is this just affects the temperature range of the auto setting and shouldn't be nuking the entire AC system.

Coreadrin

I'll get him to double check the pressure and the safety switch for it, thanks. And thanks for the tip about the drier, I will pass it on.