Hi every body,
I have problem with my 2wd 2000 gmc jimmy when I switch ac on,the rpm not increase still same like if ac off nothing change and some time rpm needle go crazy up and down some time it stay on zero.

thank you

 

Could you provide more details to your description? It is not quite clear what the symptoms are. E.g. Is it engine speed? Is the tachometer needle moving erratically even though the engine speed is constant or only smoothly changing?

 

The car always run in low rpm even when I start it on. Also the rpm should increase when switching on the AC but it doesn't. Switching on or/off the AC have no efffect on the rpm speed.

thank you

 

Does the idle speed always increase when the AC is turned on in our Blazers? I know it does on my 1.8l in my Honda but that is a small motor.