A/C Fan Wiring

Hi all,

Further to the title and a similar post I listed about a week or so ago, I've managed to locate the leak in my '93 XJ - (which ended up being a loose grommet located under the passenger side kick panel - it looked like the person that replaced the antenna didn't put the grommet back in place, so whenever water ran off the bonnet/guards/front window etc... and ran down the drain channels, part of the runoff would spill into the hole and onto the passenger side footwell).... so I just pulled the grommet through again and applied some window sealant around the edges.

The problem I have now, is that the fan that works my A/C has started to work intermittently, and I don't know what wires to check to see if there is any moisture in the terminals.... FWIW, with the A/C slider set to either MAX/NORM etc.... the compressor kicks on, and prior to the water leak, the a/c was so cold I could lose my voice.

Also, with the slider set to NORM and driving at highway speeds, the air that does come out of the front vents is cold.

Any help you all can provide on what could be the problem would be great....

Thx in advance,

B Rgds,

Quarterwave

Thx fr the reply Bronco, but the thing is, the fan isn't working at all, at any speed. The only time any air comes out of the vents is when the fresh air vents are open - so, as I understand it, the outside air is being "pushed" through the ventilation system determined by how fast the car is travelling....

FWIW, the fan worked great the other day, then dropped out yesterday, then came back for about an hour today then, after I turned off the ignition, it went back on strike when I went out tonight.... hence, me thinking it's an electrical gremlin....

Any ideas guys ?

Thx again,

Q'Wave

I would check the vacuum lines first before I would start hunting down an electrical problem. Check the lines going to the vacuum canister on the inside of the bumper (passenger side).

Hi XJade,

Thx fr the post. I just went out to the Jeep and had a look for the bottle as mentioned in yr reply. After having located it, it seemed to have just one rubber hose connected to it (sort of like a right angle), which seemed to be in good condition. There was an electrical connector of some sort that was hanging with a bunch of other wires near the passenger side front light, but it as far as I could see, there was no place for it to be attached to on the black bottle.

FWIW, the bottle seemed to be in good condition, although where is it mean't to be attached on the body ? B/c mine is just sort of wedged between the front bumper and a type of subframe....

Additionally, I had the A/C on while I was looking at it (naturally the fan in the dash wasn't working), and listened for a leak all over the engine bay, the dash and the bottle itself, but I couldn't hear one.... Is it time to just take it to a shop and prepare to fork out $$ ?

Thx guys, any ideas for me to try would be great.

B Rgds,
Quarterwave

No electrical connectors go to the vacuum bottle. But to my knowledge there should be more than one vacuum line going to that bottle. On the passenger side firewall there is a grommet next to where the heater hoses connect to the heater core. There should be two thin vacuum lines (mine are plastic PVC tubing) coming out of that grommet. One tube goes to the heater control valve and the other runs down along the fender down to where that vacuum bottle is in the bumper. That line has affected my ventilation and AC problems in the past. Not sure if that is your culprit.

Check around the battery area and see if you can see any rotted out PVC tubing or vacuum hose. They should all connect to that bottle. When I bought my XJ all those lines were brittle and the previous owner had jerry-rigged everything in place.

That bottle should be bolted to the inside of the bumper. Make sure yours is bolted down or it will bounce around and vacuum lines will become disconnected. I have relocated my bottle to the engine compartment. That way I can keep an eye on it. :looney:

Hi XJade,

I located and checked all the hoses as mentioned in yr msg, and they are all in good condition, with no visible signs of crumbling or spongy-ness....

Any other ideas as to what it might be ? If not, thx a bunch for yr suggestions.... I have a suspicion that it's maybe just a bad fan switch, but it's just a hunch. If anyone else out there has heard or dealt with a similar problem, pls let me know what the solution was so that I don't get ripped off if I end up taking it to an A/C specialist....

Thx,
Quarterwave

Quarterwave, FWIW, I had my 89 XJ in the shop yesterday to find a leak in the A/C. They told me they couldn't find one in the engine bay, but it might be under the dash. I told them I would take the dash out and bring it back. I went to turn on the A/C, but the fan wouldn't blow. If I turned the fan to HI, it would work, but not in any of the other positions. I poked around and found that there was a four wire plug unhooked on the right passenger side above the vacuum actuated valve. I opened the panel and it revealed two little wire coils and some resistors. I'm guessing it's either the blower motor resistors or the A/C thermostat. I plugged it in and my fan selector works at all speeds now.
I also had the vacuum problem, but it was totally different symptoms, as the fan worked, but air would only come out of the defrost.

Shawn

Hi Shawn,

Thx fr the post - just a quick question, where can I locate the vacuum actuator valve, and how can I access it, so that I can check it out. Also, are the wires any specific colours ?

Thx fr the help,

B Rgds,
Quarterwave

Actually, I'm not sure if that's the correct term. My FSM calls it a vacuum motor. It is the flying saucer shaped thing with an actuator arm coming out of it under the lower dash panel on the passengers side, right above where a passengers shins would be. There are no wires to it, only a vacuum hose. When you input where you want the air to come out on the dash panel, it sends a vacuum signal to this thing, which moves a remote door on the heater box. The 4 wires mentioned in my previous post were not adequately described in the FSM, so I'm not sure exactly what they are. The wires on mine ('89) are: brown w/ black stripe, orange w/ black stripe, white, blue. Hope this helps.

BTW, I tried disconecting it again, just to verify that this was the problem, and it definitely was. Same symptoms as my previous post.
Shawn

Hi Shawn,

I just had a look @ the parts mentioned in yr msg, and even after plugging it all back together again, still no avail. I unplugged the vacuum hose, heard the pressure escape, then plugged it back in, and fired up the engine. The arm that operates the vent selector started to move when selected on the control panel, and it seems that it's opening the vents as it should.

However, the problem of having no fan unfortunately still exists. Further to the four-prong connector, did you unbolt the housing to the big black box that it's connector is attached to ? B/c I just unplugged the connector, checked for any debris etc.... then securely plugged it back in again....

I'm still starting to think that maybe my fan switch is bad ? Anymore ideas ?

Thx again,

Quarterwave

Any chance you can swap out that switch with a friend's just to make sure? I think they're kinda pricey.

Unfortunately no. Looks like I'm going to head down to a local A/C place and get them to do a check/diagnosis on it, then I'll try and do the work myself - if it's not too difficult, b/c my mechanical expertise is marginal at best !

Thx for the suggstions,

Quarterwave

Hi All,

OK here's the latest.... I went down to a local A/C guy who told me that the problem was with the switch control in the unit that is housed in the centre of the dash. So, with the kind assistance of another member of this forum who was parting out an XJ, I purchased the replacement unit off him and just installed it all a few minutes ago.

Unfortunately, it's still not working. While I was at it, I checked the resistor located just under the passenger side footwell, and, it looked a little bit oxidized but there were no broken coils or leads.... so I think that that's ok.

I'm starting to think that it's the blower motor, although I'm not sure on how to take that out. Any ideas ?

Thx again,

Quarterwave

In my old Blazer I had this problem... sometimes the fan would start other times it didn't, so getting A/C on a hot day was a gamble. The motor always sounded like it wanted to go but didn't actually ever start. This is how I handled it.

take out the blower motor but leave it hooked up

start car in nuetral, you hold on to blower motor by the back(keep your fingers out of the way)

have a friend start the a/c, watch the motor, it might seem like it's trying to go but can't

now give the squirrel cage a good spin, it should start to go full blast on it's own now.

it is somehow not able to get itself started by itself. Bad motor
--------------------------------------------------------------
Long story short I had all the problems you are describing and I replaced the motor and the world was right again.

Good Luck

Thx Blaze - I just phoned my local discount auto store and they've got one in stock for cheap - any ideas as to how to remove it ? B/c my Haynes manual says that it's located in the engine-bay side of the firewall, but the water washer bottle is in the location that the book says it should be, and it looks like it's up under the dash on the passenger side....

Thx again,

Quarterwave

well you know it's going to be on the firewall most likely on the left(looking into the engine bay) I can't remember off the top of my head. As for removal, it's pretty simple, just a few screws to take out. I'm not sure about the jeep but you might have to take something else off to get it out( the blaze's engine bay was soooo big you didn't ever have to take something off to take whatever it was you were trying to replace off).

It's kinda flat looking, black, and the motor housing sticks out.

Lemme check the jeep to make sure it's on the outside, it most likely is

This is probably a 30 minute job.

Hi Blaze, thx fr the tip. Yep, it ended up being the A/C blower motor. I just pulled out the washer bottle, unplugged the blower wires and then unbolted the whole assembly from the engine-bay side of the firewall.

Then, using some pliers, undid the little clamp on the fan shaft and the fan came right off. Only took about a half hour and saved myself about $150 !

Thx again for all the help guys.

B Rgds,
Quarterwave