87 Grand Wagoneer.. No A/C

[Rex]

87 Grand Wagoneer has no A/C. When selector is turn to A/C, the fan does not run. The compressor clutch doesn't engage. Jumped the low pressure switch and didn't change anything. All other heating functions work fine. Is my problem in the heat-a/c control?
Thanks,

[64Trvlr]

It could be the clutch or switch. Did you run power to the clutch and see if that works? When you put power to the clutch w/motor off the clutch will click, if so it's good. If so you have a bad fuse, bad switch, bad wire. If that doesn't work the clutch is probably bad. http://www.ifsja.org/ubb/cool.gif

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http://www.mindspring.com/~tubefish/images/Traveler1sig.jpg


64 Traveler, 350/sm 465/
np 205/ d 44 ft and rear
w/4:88's,33.950's,Line-x interior

60 Willy Wag, Superhuricane6,T90,D18,
D 27 and 44, 4:88's

66 Wag,327,400,20,D27,D44
4:27's

[87grand]

AC IN MI??? Just kidin sounds electeral. I would take one problem at a time check each componet seperatly and see if is doin its job. If all eles fails turn it in to Onboard air and be realy "Cool"



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87 Grand Wag (stock)
3" Body lift, "trimed" fenders, 30x9.5 knock off tires.
Dueteronomy 6:6-7

[Rex]

It was 89 plus 90% humidity yesterday! Doesn't happen very often, but us Michiganders aren't used to it. Clutch works when shorted. ALL functions of switch work execpt a/c. Checked all fuses in fuse panel under drivers dash. Looked for loose wires to a point... Short of tracking the complete wiring down. Do the switches go bad on these?
BTW... This is the "integrated" a/c-heat switch, as oposed to the under dash unit of the earlier years.

[BobBarry]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Rex:
87 Grand Wagoneer has no A/C. When selector is turn to A/C, the fan does not run. The compressor clutch doesn't engage. Jumped the low pressure switch and didn't change anything. All other heating functions work fine. Is my problem in the heat-a/c control?
Thanks,<HR></BLOCKQUOTE>

It could be; despite the appearance of integrated controls, the A/C system is entirely separate from the heat/defrost system (they even have separate fans, and separate fan switches, even though they're controlled by the same dial), so it can fail individually.

I would first check the fuses. Then I would check if the dash switch is actually sending current to the A/C clutch.

If it's not a fuse or a switch, then you're going to start testing continuity of the wiring; a wiring diagram would be really helpful for that.

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Bob Barry<UL TYPE=SQUARE>* '78 Cherokee 4-door
* '88 Grand Wagoneer[/list]http://studentweb.providence.edu/~rbarry/wheels/

[64Trvlr]

Rex
If everything works but the switch, guess what. Looks like time for a new switch or you can just wire in an additional switch so all looks stock in the dash. Just run a wire from power to a fuse to the switch then to the a/c clutch and you're done. http://www.ifsja.org/ubb/cool.gif

------------------
http://www.mindspring.com/~tubefish/images/Traveler1sig.jpg


64 Traveler, 350/sm 465/
np 205/ d 44 ft and rear
w/4:88's,33.950's,Line-x interior

60 Willy Wag, Superhuricane6,T90,D18,
D 27 and 44, 4:88's

66 Wag,327,400,20,D27,D44
4:27's

[Rex]

Any hidden fuses, relays or circuit breakers?
I don't have a wiring diagram, so I'm a little in the dark past checking the simple stuff. My guess is that the switch is big $$$ so I don't want to buy it until the simple stuff is done first.

[64Trvlr]

Why don't you put a jumper wire to the clutch and see if the a/c gets cold? Then you can just run a new wire and switch and be done. http://www.ifsja.org/ubb/cool.gif

------------------
http://www.mindspring.com/~tubefish/images/Traveler1sig.jpg


64 Traveler, 350/sm 465/
np 205/ d 44 ft and rear
w/4:88's,33.950's,Line-x interior

60 Willy Wag, Superhuricane6,T90,D18,
D 27 and 44, 4:88's

66 Wag,327,400,20,D27,D44
4:27's

[Rex]

OK.
Problem is solved! Turned out to be three things. First was the blower resisitor. There is one for the a/c as well as the heater. Second was the a/c controler. It is a small black plastic box located under the dash next to the relay. It had a break in the printed circuit. And last was the thermistor.. I just jumped it as I didn't have time to get another one yet.
Can anybody tell me what this themistor really does? It looks like it just shuts down the compressor if the evaporator gets too cold. Is it really needed?
Thanks,
Rex