98 Taurus AC Compressor

[annie5379]

My 1998 Taurus AC suddenly died. The compressor is not working at all... Where is the fuse located?

Thanks!!!!!!

[shorod]

There are a lot of things that could cause the A/C to stop working, but starting by checking the fuse is reasonable. However, if you find the fuse is blown, don't think that just replacing the fuse will fix the problem. If the fuse blew, it blew for a reason. Chances are better that you have an issue with the R-134a refrigerant charge than an electrical issue.

That being said, the fuse for the compressor clutch is fuse 27 (10-amp) in the engine compartment fuse/relay panel. It provides fuse to the field coil through the A/C clutch relay also located in the same panel. If the fuse if bad, you should check the diode in the same panel prior to installing a new 10-amp fuse.

-Rod

[tripletdaddy]

I think Rod also meant for you to also check the AC relay which is with the fuse and diode. Rod, when a diode goes, is it visually obvious? I've not seen a relay with any external indication it went bad. Have you?

[shorod]

If the fuse is blown, the diode would be one quick item to check as to what may have caused the fuse to blow. I doubt the relay would cause a fuse to blow. I was focusing on what could cause the fuse to go. If the fuse is not blown, then Annie needs to post back for further support, or find your post from a week or so ago that details what the pressures need to be, etc. to allow the A/C system to engage the clutch and work properly.

And you're right, typically relays will not have external indications that they are not functioning. Often the contacts will burn up or get so much carbon from arcing that they won't allow sufficient current to flow.

-Rod

[tripletdaddy]

And a bad diode that may blow a fuse would look like?

[shorod]

Originally Posted by tripletdaddy

And a bad diode that may blow a fuse would look like?

Electrically or physically? Electrically it could look like either an open or a short. If shorted, it could cause the fuse to blow as it would be a direct short to ground. If open, it could cause the fuse to blow since the collapsing A/C clutch could send a spike back into the charging system. However, this spike would be quite short in duration so it probably wouldn't actually blow a fuse.

Physically, I'm not sure you'd see that it's blown. Often these are encapsulated in a plastic housing.

I'm not saying this is a likely culprit, just something to check that would often be overlooked.

-Rod

[tripletdaddy]

So, typically, a failed diode won't look melted, burnt, etc., but it could, just not likely? It would just fail without any exterior evidence? Not like a short or other overload, heat generating failure that is visible by a discoloration and possibly melting?

[shorod]

Right. It often will be the fuse that powers the clutch circuit that will be burned. But even with the fuses, they don't necessarily look bad until you remove them from the fuse block. The diode in late model cars is typically in the fuse panel too, but rather than just looking at it, you'll often need to check them with the diode test feature of most multimeters.

-Rod