94 a/c controller problem

[copper_94]

has anyone seen this problem?

the power to the a/c head seems to go off/on at random intervals. the
backlighting doesn't go out, just the temp digits int he lcd and the green
light over the button selected. when it comes back, it goes through the
normal power on sequence (showing the internal setting, then the outside
temp).

it does it randomly, the time off is random, when sitting at a light, and
also, oddly enough, will occur sitting in my garage with the engine off but
the ignition on.

i've swapped out the controller head with the one from my wife's 96, but the
problem did not follow the controller. i've checked the fuse for this
circuit and there is no corrosion in the fuse socket, and replaced the fuse.
i drove around with the head sticking out and moved all the wires that go
into the head without being able to cause the problem.

i don't have a manual for this car, so can't find out where the ground
points or power is provided. is there a relay that provides power, or
something else like another controller (besides the esm) in the circuit that
could cause such an intermittent problem? the bundle of wires dives behind
the dash down into somewhere near the driver right foot, but i can't seem to
figure out how to get the side panel off, or know what else it's connected
to there.

thanks,
charlie

 

[rlg]

there is an A/C programmer mounted on the drivers side under the dash, but I don't know how the wiring would be on a 94, mine went bad on the 90.

 

[copper_94]

there is an A/C programmer mounted on the drivers side under the dash, but I don't know how the wiring would be on a 94, mine went bad on the 90.

programmer? what does that do? where under the dash, and what did you have to remove to get at it? i've looked around and can't find how the panel under the steering wheel or to the right of the driver knee come out.

 

[rlg]

the programmer regulates airflow, works in conjunction with the head unit and the ECM.

It is located to the rightof the steering wheel. you will have to lay on the floor and look up , you will see a box with a vacumn cluster and a blue plug for the electronic connection. It's a little tricket to get out , it took me about an hour to do

 

[rlg]

if you have a fax # I can send you the pages I used from my 90 FSM. I got a lot of help on this forum. Toptec and Twisterup among others know alot on this subject

 

[TWISTERUP]

Ground point for the head and programmer are bolted behind the left kick panel W/panel removed you should see a couple of black wires bolted there...be sure they're clean and tight. Normally if the system "sees " a fault the LED above the "mode" button will flash...but I'd check anyway...after the problem has occured and you have lights again on the "head"---push and hold both the up and down fan arrows at the same time for 5-10 seconds..the display should then show "00"...then push the auto fan button....if there is a fault code ...a number (fault code) will be displayed---this must be done when the problem occurs without turning the ignition off... because the system has no memory other then faults it sees with each key cycle..the only fault it "stores" in memory is low freon which is not related to your problem.

If you have no codes i'd agree with "rig" It's likely a bad programmer...I'd check the connectors to the programmer to be sure they're locked in tight (it has electrical and vacuum connections) but i'm speaking of electrical in your case. The vacuum nipples are fragile so take care if you do remove the programmer. Well i hope i've given you a starting point anyway. I'll assume you've already checked the fuses for clean/tight connections---anyway post back with what you find--one of the members will try to help

 

[TWISTERUP]

Any luck yet ?

 

[copper_94]

Any luck yet ?

i've managed to crawl under there and look around. not very much room is there? i don't work well hanging upside down, and i'm reluctant to remove the seat to more easily get to it. i haven't actually seen the programmer that was referenced, and i can't figure out where the connection points are to remove either the plastic shield/carpeted panel under the steering column or the side panel on the tunnel.

i've just ordered the fsm for this car, and it hasn't arrived yet. i'm hoping that it will have pictures of how to get off those panels, and exactly where this part resides.

 

[copper_94]

Ground point for the head and programmer are bolted behind the left kick panel W/panel removed you should see a couple of black wires bolted there...be sure they're clean and tight. Normally if the system "sees " a fault the LED above the "mode" button will flash...but I'd check anyway...after the problem has occured and you have lights again on the "head"---push and hold both the up and down fan arrows at the same time for 5-10 seconds..the display should then show "00"...then push the auto fan button....if there is a fault code ...a number (fault code) will be displayed---this must be done when the problem occurs without turning the ignition off... because the system has no memory other then faults it sees with each key cycle..the only fault it "stores" in memory is low freon which is not related to your problem.

If you have no codes i'd agree with "rig" It's likely a bad programmer...I'd check the connectors to the programmer to be sure they're locked in tight (it has electrical and vacuum connections) but i'm speaking of electrical in your case. The vacuum nipples are fragile so take care if you do remove the programmer. Well i hope i've given you a starting point anyway. I'll assume you've already checked the fuses for clean/tight connections---anyway post back with what you find--one of the members will try to help

i actually tried this before originally posting. the problem is when the power is lost to it, it seems to me it would lose it's fault code. when it was working, i did try to get one, but it only gave a 00 code as it would appear to the controller head that it was just powered on, so not have any states stored.

 

[rlg]

While you are on your head looking up ,look to the rear of the car to your left of the Steering wheel , you will see the blue plug and the vacuum collector. 7mm nut, the press nut that holds the vacuum connector has to be pryed off with a small scewdriver. Do this before removing the 7mm nut. the electrical plug is long but the vacuum lines are to short and have to be removed first.

to remove bolster, there are several interior screws and one nut at the back , on the side mine had two hex head interior screws. Its a little trickey on the right side if I remember right.

after that you will see how to remove the metal piece.

the box is about 6x4.5 inches and about 2 inches thick.

Good luck

 

[copper_94]

While you are on your head looking up ,look to the rear of the car to your left of the Steering wheel , you will see the blue plug and the vacuum collector. 7mm nut, the press nut that holds the vacuum connector has to be pryed off with a small scewdriver. Do this before removing the 7mm nut. the electrical plug is long but the vacuum lines are to short and have to be removed first.

to remove bolster, there are several interior screws and one nut at the back , on the side mine had two hex head interior screws. Its a little trickey on the right side if I remember right.

after that you will see how to remove the metal piece.

the box is about 6x4.5 inches and about 2 inches thick.

Good luck

well, i spent about 2 hours trying to get the programmer out. i simply can't get the vacuum collector plug out. i pried for all i could and it wasn't budging. does it have a catch or something holding it in? you can't actually get to see much of it so i can't tell.

i wiggled the connectors around, and checked the ground point under the left kickpanel, and couldn't get it to power off when doing that. however, just sitting there in the driveway with the key on (engine off), it did flicker a couple times so it isn't something caused by vibration or a loose connection.

 

[rlg]

there is a metal push clip that holds it in,. take a long small blade screwdriver and pry it off.

 

[copper_94]

Followup: it turns out to be a defective controller. i spent hours trying to get the push clip off, and finally took it to the shop when i had my oil changed for them to work on it. it took them 30 minutes to get it off, so i don't feel so bad.

thanks for the tips.