A/C Light comes on for 1 second then blows fuse...

1999 tacoma 2.4

I am troubleshooting the AC and replaced the 10amp fuse - which was blown and put in a new button assembly. Now everytime i start the engine and turn on the AC the light goes on for a second and then off again. I check the fuse and its blown. Is this the heater relay that needs to be replaced? Also which one - there is a large black relay box at the bottom of the fuse box and a 40 amp fuse at the top that is heater related? Any opinions? Thanks

also the green 40amp fuse box - i took the top off and its just a metal band going from one side to the other - it is NOT broken - i am assuming that it is ok but not sure what its supposed look like inside.

 

I am suspecting the compressor clutch is pulling too many amps. Depending on how "mechanical" you are... I disconnected the pigtail on my 96 and ran a fused jumper lead to the pigtail and then to the battery as a test, yep the 10 amp blew but the 15 amp didnt. I replaced the compressor clutch, not that difficult of a job at all. I DO NOT recommend you putting a 15 amp fuse in the trucks fuse holder to do this test.

 

Unplug the A/C compressor and see if the fuse still blows, if it doesn't then you likely have a shorted A/C clutch. If it still blows you either have a short in the wiring or the A/C Amplifier itself is shorted internally.

 

Thanks, all I will take a look and disconnect the compressor and see if the fuse still blows. I can possibly replace the compressor clutch if it’s determined that that’s the problem - i’m best at mechanical type stuff like that. When it comes to electrical and schematics and such, I’m as useless as tits on a bull.