AC fuse keeps blowing

Why?

 

Check the compressor clutch and any relays for shorts.

 

Is there a relay for the clutch?

 

Welcome to the forum!!

Indeed there is It is called the Heater relay.

Which feeds the AC fuse.

You have the Ac amplifier several switches wiring many places that could be shorted causing to much current to be drawn on the circuit.

Good luck!

 

Did anything change? New parts/service prior to issue?
Is it the right size fuse?

 

Fuse is correct but don't see a relay that is labeled for the compressor clutch..is there one?

 

Well this is certainly a timely discussion. Got a couple days off, decided to tackle my AC that stopped working "a while back." Welcome aboard @Don walsh maybe the pic below and video will help.

For reference mine is an '03.

I was following this guy's excellent electrical diagnosis and my fuse layout is different, got lost at the point where he suggests swapping the horn and AC relays. Looking at the FSM and a couple other resources, I figured out (I think?) the one labeled HEATER controls the AC, the one labeled J/B is horn (24 and 26 in this diagram.) As it turns out, I don't think they are actual relays, they are high amp fuses, so I'm even more confused now. :-\ My layout:




And as you can see, the casing totally disintegrated swapping them back (still works though.) I can't find ANY resources to replace this bugger, not any of the Toyota sites, O'Reiley's, AutoZone . . . it's about an inch and a half long with two terminals, does anyone know the P/N or have a source for this fuse? (never mind, they're showing up in results now LOL)

If it is a fuse, where the #$%#$% are the horn and AC relays?

Also for reference, here is the '03 FSM page which kind of agrees with my findings so far. In the diagram #1 and 2 are the fuses, indicates they're not even relays. :-\

I think my magnetic clutch is toast but haven't finished the power-on, it turns but does not engage.

 

Same issue with my 96 4X4. I ohmed everything and found no issue. I put a 15 amp fuse in and zero problems after that.

 

An old fuse sometimes just gets weak and blows. May mean the circuit is drawing more current as it gets old, may mean the fuse contacts were oxidized (Ohmic) and adding heat to the fuse, or it may mean the fuse just degraded after over 25 years. If it works well after replacing the fuse, move on to the next project (or problem).

 

Have you figured out your problem yet?

in your picture the black relay is the heater relay to the right of the blue relay.

Simple matter to test the magnetic clutch . Engine off apply 12VDC to the clutch it grounds through the compressor.

It is easy to see if it pulls in. Then the next step is finding if voltage is applied with the engine running and the AC on and Blower on.

Good luck!

 

Thanks, and yes, per the video link That's next, just procrastinating, putting off getting on the floor again. In the video he shows to switch the heater/AC relay with the horn relay, guess we can't do that on an '03. Since the one fuse crumbled maybe I'll just get a new one when I pick those up.

 

I can`t recall ever being on the floor doing AC work.

Unless you mean the floor of the cab i was thinking floor as being under the truck.

 

HAHA SORRY. The only way I know of to test the clutch is to take off the skid plate, remove the wires to the clutch from underneath and put a 12v power source to it to test the clutch. You know getting old sucks when you have to think long and hard about getting on your back on the creeper one. more. time.

 

I have never ever done one that way never gave it a thought .

I always reached down from the top.

In my case the getting down is easy the getting up is the challenge!!

 

Right? Some people like to lay in their yard staring at the night sky. A lot of times I lay under the truck staring at an undercarriage and ponder the universe. LOL

 

Well, that turned out to be such a bad can of worms I still haven't applied power to the clutch. :-\