Compressor cuts off on high blower

[abunaione]

1999 Frontier. 4cly.
The compressor cuts off when the blower is on high speed.
Blower works fine
A/C works fine in the other three speeds.
I did have to change the blower resistor last year.
No low blower speeds.
Looked at the wire diagram, and only thing I can see that might be a problem is the amplifier.
But I'm not seeing how switching to high blower would make a difference.
Don't use high much, just to cool when first getting in.
Any ideas?????

[Cornbinder89]

I'd have to see the wiring diagram, as it is impossible to know the wiring of all vehicles. Coupla of thoughts. 1st and foremost, the problems seams to be an electrical one and not anything in the refrigeration cycle.
Did you have to change the fan switch? Does it have a separate A/C switch to turn on? Most systems have to have both the fan in one of the "on" selections AND the A/C button depressed. Your fan switch may be dropping the feed to the A/C button on the high setting. This assumes a mechanical control where the fan switch controls the fan directly, and not though a controlling logic controller.
I'd have to have the diagrams to advise further.
If you are a gambling man and want to try "throwing parts" at it, I would try a fan switch. It is not my way to throw parts at problems, as you don't often get lucky the 1st time around, but that would be my 1st guess.

[Cusser]

I have 1998 and 2004 Frontiers with same engine as you. Neither has had this issue, but I'm somewhat familiar with it. See my saved information below:
AC Thermal Control Amp R&R (AC de-icer switch, temperature control switch, thermostat, Thermo Control Amp)
http://www.clubfrontier.org/forums/f46/diy-guide-how-change-thermal-control-amp-1st-gen-frontier-72291/
#27675-9Z000 http://www.courtesyparts.com/27675x-amplifier-thermo-frontier-d22u-1998-2004-p-64469.html

http://www.clubfrontier.org/forums/f46/diy-guide-how-change-thermal-control-amp-1st-gen-frontier-72291/

Part #27675-D22U002 http://www.courtesyparts.com/27675x-...4-p-64469.html

"fixed the A/C issue last week! ordered both the resistor and thermistor just the other didn't work. I would send the unneeded part back
Well the resistor came in first. Easy swap, just two screws. That fixed the fan speed issue and the A/C was working. While my wife drove into work in her truck, she called to tell me the A/c stopped working again, but the fan speed worked fine.
Waited a few more days and the thermistor came in. It was an easy swap since I've replaced this part years ago. Simply removed the glove box.
The A/C has been working perfectly ever since! I guess the used resistor that my uncle gave me years ago as a spare was bad as well. Thankfully it was an easy and fairly inexpensive fix considering it's the A/C! I should have ordered these parts to begin with but it's been so long since I've swapped them out, I forgot all about the thermistor. and figured the resistor would be functional.
Lesson learned. Most of our A/C issues should begin with swapping out these two parts first!"

[Cornbinder89]

So much better when you have advice from someone with experience on the model in question. Thanks!

[abunaione]

Might just be the problem.
But I'm wondering why the A?C would work fine in low speeds and not on high????
Part is not discontinued, but I did find it on evilbay.
I'll order it anyway.

[Cusser]

Like I mentioned: neither of my two Frontiers has had this issue, so I have no firsthand experience with that.

I will say that it measured 112F yesterday, and I drove 95 miles in my 1998 Frontier (260K miles) and it was fine. And I will also throw in that I almost always just leave the AC on speed 3, rarely use speed 4. After a couple of minutes of operation, switch to recirculated air position; at start up, the hot outside air is actually cooler than the air inside the truck.

[Nacho]

Replace the blower switch