Bad A/C relay?

[redheddude222]

I replaced my A/C compressor in hopes of getting the system in my mx3 working again. It blows ice cold at idle, but kicks the compressor off as soon as I start moving. Here is what I've checked so far:

High pressure switch is not the issue. Bypassed it and nothing changed.

Clutch is working fine. Jumped the compressor wire straight to the battery and drove it around, blew ice cold the whole time.

Condenser fan works properly when the A/C switch is on, no issues there.

That's all I've got so far. Is there a way to test the relay(s) to make sure it's working? I'm also thinking about just hard wiring it so that anytime the A/C switch is activated the clutch will be engaged. Then I run the risk of damaging something since it won't be able to cycle properly.

[MazdaNoob]

isnt there a high load cut-out for the ac in the mx3?

[redheddude222]

No idea. And the Chilton manual I have says that it doesn't include any part of the A/C system due to EPA hazards. :/

[MazdaNoob]

the mx3 stock ?

[redheddude222]

Stock with a BPT swap. A/C worked fine when I got the car, then started having this issue out of the blue.

[MazdaNoob]

there is an ac relay but what you are describing is too consistent to be just a short or failing relay i would think . mess with the tps ? . every time you come off idle it shuts off the compressor . just brainstorming here

check for power at 1J on the ecu ( assuming bp26) and see what it does while you blip the throttle. then swap in a stock bp ecu and see if it does the same ( pinout for ac is the same )

[me109]

I had a consistent inertial AC failure recently. Maybe your issue is similar. My AC clutch connector had about .5" of exposed wire trailing it, so every time I would slow down it would swing forward and short itself on the rad support. It blew a bunch of AD FAN fuses before I found it, and it was very consistent. I wrapped it in electrical tape and it's been fine since.