AC fan problem

[VIRGIN87T]

I noticed after turning my car off yesturday it was really hot and boiling over into the overflow canister. I noticed the dual fans were not on. Well I let it sit and cool down. I came out later and started it on again and turned on the AC to see if that turned the fans on, but it did not, the air didnt even come on! It was blowing, but only hot air, the compressor never came on. I also took off the plug on the AC lines and jumped it to see if the fans would turn on, but still no luck. Doesnt seem to be getting any power. I checked all the fuses and all are intact. Any ideas? Is there a resister/connection that controls both the fans and AC? TIA

 

[SHADOWII]

Might check the .....

coolant fan relays on the driver/s fender. the one closest to the windshield is the fan delay relay, than the low and hi speed relays.
Coolant fan temp. switch, mounted on top of the manifold, in front of the fuel reg. and next to the t/body.
Check fuses and fuseable link "A". for a/c.
" a/c cut out relay, located between esc and fuelpump relay on passengers side fender.
Hope this helps.

 

[VIRGIN87T]

coolant fan relays on the driver/s fender. the one closest to the windshield is the fan delay relay, than the low and hi speed relays.
Coolant fan temp. switch, mounted on top of the manifold, in front of the fuel reg. and next to the t/body.
Check fuses and fuseable link "A". for a/c.
" a/c cut out relay, located between esc and fuelpump relay on passengers side fender.
Hope this helps.

I have extra fan relays that I tried out today and it still did nothing. These relays wouldnt cause the AC compressor not to come on would they? I also disconnected coolant temp switch and jumped it to a ground and nothing happened. I have already checked all the fuses, what other fusable links are there? Would the AC relay on the passenger side also cause the fans not to work?

 

[SHADOWII]

The fuseable links.......

are connected to the pos. post of the starter solenoid. There are four of them, 3 wires, but 4 fuseable links attached. I don't remember what the color of the link wire is, but you would do good to check them all while you are down there. I would also recommend moving them up to the fire wall or bat. post or fender. I think casper's offers a kit. the links have a tendency to clear at the worst times. also, what type of a/c control do you have? the manual or the electronic?

 

[VIRGIN87T]

I will look into that kit from Caspers. I have the manual type a/c control.

 

[SHADOWII]

This may be difficult.......

to follow, but here goes. Now these are parallel circuits. the first circuit is from the fuse block-ecm-sol 10 amp fuse, pink and blk wire, to pin "B" brake switch. continues down to pin"A"at A/C cut out relay. goes out pin "C" to ecm on a grn/yel wire. these pins, A&C are for the coil in the a/c cut out relay.
Now the 2nd circuit,from the a/c 25amp fuse, on a brown wire, to pin E on the a/c function switch. Exits on 2 pins, B, a brn/wht wire. and C lt grn wire. the latter wire, goes to pin B on the pressure cycling switch and exits on pin A as a lt blu wire to pin D on the a/c cut out relay and also to the ecm. it exits from the cut-out relay at pin b as a drk grn wire,to the a/c compressor clutch pin A. exits at pin B as a blk wire. note:there is a diode between the pins A/B. he blk wire goes to the hi press. c/out switch at pin A. exits on pin B to a splice, one to grd and the other to the coolant fan. Does this help?

 

[VIRGIN87T]

I ordered new fusable links from caspers yesterday, as well as a new A/C cut-out relay and A/C plug with diode just in case.

Wow, that is a lot of wiring but does make sense. I will have to get out the good ol' test light and see if there is power to the fuses you have mentioned, to the relay on pin A and D and also try to check if there is any output on pin B and C. Thank you so much for the very informative information. I got some wires to track now.

 

[SHADOWII]

Ok!

I ordered new fusable links from caspers yesterday, as well as a new A/C cut-out relay and A/C plug with diode just in case.

Wow, that is a lot of wiring but does make sense. I will have to get out the good ol' test light and see if there is power to the fuses you have mentioned, to the relay on pin A and D and also try to check if there is any output on pin B and C. Thank you so much for the very informative information. I got some wires to track now.

If you get stuck, holler back.:smile:

 

[VIRGIN87T]

Well I checked the ecm-sol and AC fuses and both are getting power. I skipped the AC controls for now and went straight to the AC relay. I found that pins A C and D were all getting power?? Arent only pins A and D supposed to be getting power to the relay? And outputted on pins B and C? I replaced the relay also. The fan pressure switch on the AC lines is also getting power on the middle pin (green w/black wire). I thought I ordered the compressor plug with the diode attacted but did not. Being that they are all in parellel, if one component went down, all components after it would not work, correct?

 

[SHADOWII]

Sorry it's...

taking so long to reply, been busy. YOu have bat. voltage to the pins AC&D because you are effectively a straight wire from the B+ to those pins. pin c receives a ground signal from the ecm, which energizes the coil & closes the contact, sending B+ to the a/c compressor clutch at pin A and Pin Bgoes to pin A of the hi press. c/o switch. from pin B of the c/o press. switch to grd. and coolant fan.
It would appear that the ecm is not closing the c/o relay, if you are not getting power to the a/c clutch.:frown:
NOTE: Do not measure resistance on the ecm, can burn out the chip.

 

[VIRGIN87T]

Don't worry about it, I really appreciate all of your help and knowledge. My work place is only 1 mile from home, so my car is still usable in its condition.

I forgot to mention that I did try another ECM and chip configuration with no luck, it still reacted the same way. When the A/C is turned on from the off position the RPMs do increase to compensate for the compressor that is supposed to come on. I have yet to check if there is power to the actual compressor, and I am going to be ordering the new plug with diode ASAP just in case. A few questions if you dont mind:

1. How many connections are there on the compressor?

2. I have also yet to check the fusable links, but being that things are getting power, this probably isnt the issue, correct?

3. Also, with my horrible luck it can be very possible that the extra fan relays I tried could have been bad (wouldnt surprise me), would bad fan relays break the parallel link and cause the compressor to not turn on?


Thanks again for all your help and knowledge, it is much appreciated.

 

[SHADOWII]

I will try to.......

answer your questions a little later in the day. I have to go and repair my daughters vehicle right now. but the computer(ecm) supplies the grd so the compressor can turn on, based on other inputs, so you should be able to chase down the problem as we are eliminating what is not at fault and get an idea of the overall condition of your system.

 

[SHADOWII]

On the ...

compressor, there is only the clutch connector. on the gas line behind the compressor is the hi press. cut out sw. and the cycling switch on the accumulater. So, answer to #1 is 1.
#2-correct
#3-It would have to be a dead short. but they both ground out at the back of the passenger side cyl. head. that grd. has to be good.
try to verify power reaching the clutch connector on pin A,

 

[VIRGIN87T]

I was finally able to check on the car today. Got out the test light and there is power reaching the green wire to the compressor. I tried looking for the ground but was looking on the drivers side. It got too hot outside so I retired for the day. I will get back out there to check the ground on the passenger head. Is this ground on the head just for that circuit? Is it a couple wires with eyelets? Or is it like a grounding strap? Thanks for all your help.

 

[SHADOWII]

If I remember...

correctly, it's 3 wires w/eyelets.

 

[VIRGIN87T]

Well last weekend I tried to get to those elusive wires on my driveway but just couldnt do it. Took it to an old workplace of mine and put it on the lift. The wires were still connected but really dirty and the two thinner guaged wires were exposed. I just clipped them off, ran them back up under the hood and grounded them to the firewall. IT WORKS!! :biggrin: What a relief. I know grounds are touchy and very valuable connections but something like this just makes you realize again that they need to be perfect to work correctly. Thank you for all your help and knowledge SHADOWII, it is much appreciated.

 

[SHADOWII]

Good news!

and your wecome!:smile: