HELP WITH MY WOT A/C RELAY

[timewarped1972]

when i bought my car, the guy i bought it from said sometimes he had to replace this relay, on the fenderwell below where the maf bracket bolts up. my a/c recently stopped working, the compressor is not coming on, and prior to this it blew quite cold.....i found the relay he refered too, along with a paper he gave me, a diagram rather, of this relay and it says it's the wot cut out relay........could this indeed be the problem and has anyone else ever had problems with this thing? called auto zone and they dont have it so may be dealer or is there anywhere else that may carry this if thats what it is? any advice appreciated...

 

[HISSIN50]

there is wiring for the a/c clutch that goes through the relay. it first goes through the LPS (pass firewall corner - easy to spot). make sure there is continuity through the switch. then the juice goes through to the WOT relay. you can check for input and output and see what you are missing. if the LPS is bad or your charge is low (or bad wiring), the clutch wont energize.
some info for schematics can be found here, courtesty of Tom and S&2B's:
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

good luck.

 

[timewarped1972]

thanks...........well i checked the plug that goes to the ac clutch itself with ac switch on, nothing. i checked the wires that plug into the wot relay and they have juice. i removed the wot relay and checked all the connectors in it with an ohm meter and got no conductivity although im not sure if that switch is open or closed with no power to it.
there's 4 wires that go to that wot relay, a red, yellow, yellow with blue stripe, and a heavier dk blue with yellow stripe, i'm sure theres probably a way to jump it across to make sure its the relay but id rather not fry anything trying so i guess for now i'll hunt for a relay...........the guy said they were cheap and that he'd replaced a few of them since he owned the car so hopefully thats it, ....we'll see i guess...........

 

[HISSIN50]

ok, i would test the LPS. make sure that with the a/c on, there is 12 volts in and out of it. the juice goes from there to the WOT relay.

also, if you have a low side gauge (or manifold gauges), check your a/c pressure - this will help tell you if the LPS is bad or if you are indeed low on charge.

good luck.

 

[Pod]

If you find a source for the WOT relay, please let me know. The wires going into the relay have fallen apart on mine.
Can you take the black box apart? I could cut the wires and reattach them further up if that's possible.

 

[jrichker]

If you find a source for the WOT relay, please let me know. The wires going into the relay have fallen apart on mine.
Can you take the black box apart? I could cut the wires and reattach them further up if that's possible.

Time to make a Junkyard safari...

Here's some more wiring help...http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp

 

[Pod]

Time to make a Junkyard safari...

Here's some more wiring help...http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp

Unfortunately there aren't any junkyards over here in England that have Mustangs.

The wiring diagram looks promising - thanks very much for that!
If I understand it right (I'm not an electrical expert!), the red and orange/light blue wires are the one the computer uses to switch the relay.
Pink/light blue is the input from the low pressure switch
Black/yellow is the output to the compressor.
So, if I just connected the pink/light blue and black/yellow wires together, that would make it stay on, even at WOT, correct?

 

[jrichker]

Unfortunately there aren't any junkyards over here in England that have Mustangs.

The wiring diagram looks promising - thanks very much for that!
If I understand it right (I'm not an electrical expert!), the red and orange/light blue wires are the one the computer uses to switch the relay.
Pink/light blue is the input from the low pressure switch
Black/yellow is the output to the compressor.
So, if I just connected the pink/light blue and black/yellow wires together, that would make it stay on, even at WOT, correct?

No, under no circumstances modify the wiring by tying it all together. You will make smoke and kill the computer.

Best case, if you are in the military, make some friends at the motor pool & get them to help replace the relay & rewire the socket. A suitable bribe of whatever is their favorite food or drink will go a long way.

Other than that, see http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=275-226 for a relay -$6.29 US dollars.

The power wiring for the relay is 16 gauge, so you'l need some slip on solderless wiring connectors to connect it to the existing wiring.
The replacement solderless connectors for the wiring are http://www.radioshack.com/product.a...11_003_004_000&product_id=64-3133&site=search at $1.69 USD a package, 14-16 gauge wire, 5 male (you won't need them) and 5 female (these slide on the prongs of the relay).


The wire going to the computer is 18 gauge, so you'll need a slightly smaller crimp connector for it.
The replacement solderless connectors for the wiring are http://www.radioshack.com/product.a...11_003_004_000&product_id=64-3131&site=search at $1.69 USD a package, 18-22 gauge wire, 5 male (you won't need them) and 5 female (these slide on the prongs of the relay).

A crimp tool will be needed to crimp the commectors onto the wire - http://www.radioshack.com/product.a...1_009_010_002&product_id=64-2984&site=search- $6.99 USD

See http://www.radioshack.com/search.asp?find=crimp+tool&site=search&SRC=1&image1.x=45&image1.y=34 for all kinds of crimp on connectors & tools.

The local auto parts store may have all of the above items with different names, prices & part numbers.

Hint - buy more crimp on connectors than you need - they are cheap and if you mess one up or lose it, spares ones are always handy.