Why does my car only blow hot air?
 

I've been suffering with no definite answers to this problem. what would cause my climate control system to do nothing but blow hot air, ALL the time? It doesnt' matter what setting you put the control unit on, hot air and only hot air will come out. Needless to say, the AC no longer comes on, either.

I've replaced the control unit twice so far from donor cars, but to no avail. The factory service manuals I've seen online say nothing about heating and A/C.

Please help before I sell the rolling sauna.

Try this link...... http://www.teamfc3s.org/main.shtml


Hope it helps out.

the teamFC3S site
 

I looked at the site under troubleshooting... is it the part about resoldering the logicon control unit? Is that all this is, or do I have some other actuator (mode control?) or gadget? Either way, I guess that control unit is coming out again anyhow

PS.. anyone know where the hell the A/C relay is????

Please define hot air. Hot as coming from the heater or just hot air as in its a hot day in Texas, 105degrees. With the engine off, and the key on, when you touch those buttons on the LOGICON, do you hear the doors on the system opening and closing? Touch a button and you should hear a whirr and then the sound of a little door closing. Air conditionin relay? There's one mounted on the blower motor and one hanging in front of the radiator on the drivers side of centerline. Does the clutch on the compressor pull in when the air cond button is pushed while the blower selector is pushed to the right? If not take that single bullet connector on the air compressor and touch it by hook or crook to the positive post of the battery. Did the compressor clutch pull in? If it did then the compressor is ok. There is a *receiver drier* located next to the overflow tank. Disconnect the two wire connector going to it and put a meter on the two contacts on the receiver drier. Do you read continuity? Like less than an ohm? If you do not you probably have not enough freon in the system to make the circuit to the compressor.

The link basically addresses what plagues these cars the most....electric gremlins, but HAILERS's got it a bit more detailed. Do you know if the Logicon unit has ever had any of the solder joints re-soldered? I would try all. With that heat in Texas, hot air from the air ducts is way too much to handle.

I didn't have any AC issues, but my CD player and some of the dummy lights where acting up. It took a while to get that damn thing out but the soldering job fixed the light issue....CD player is still acting up. Now I have the wiper switch thing going on and well..........more gremlins.

Good luck.

The REXMAN is right. By the way, if you patch one in from the wreck yard and it does not work, do not assume that means that your Logicon is ok and the problem lies somewhere else. I've definetly been down that long dark road. Made the junk yard man rich. Now if you patched one in from a known good car, that is definetly a different kettle of fish. Gotta be something else. Did you have lots of fun hooking up that connector. No children around I hope. Talk about a lousy installation.

great info but more needed
 

alright I got the climate control unit out, and am in the process of taking it apart. The circuitry in the little black box looks ok, but I noticed some of the solder points on the bottom the the main board seem slightly corroded, as well as some one the faceplate board. Are these the ones that are supposed to be resoldered? And how the *@!%$ am I going to resolder these tiny little points? Holy crap! I think I might go looking for another at a junkyard.

Also, isn't the logicon that clock/idiot light module at the top center of the dash? Or is it this climate control job I just ripped out of the car?

Oh! Please go to the site that REXMAN referenced in his post above. It gives clear and definitive instructions on where to reheat the joints. Did you check the compressor out? And the switch at the receiver drier. A good thirty buck digital meter will pay for itself.

Dude.....you are almost there. The link I provided above shows you pics on what to solder, but I would do all. Sometimes, if you look close enough at the solder points, you'll see the cracks that form on them, hence the word 'cold joints'. Take your time and resolder all the points. Is going to take some time but it's worth the effort. If you want to get all professional on this, get some Dry Wick and then use new solder. Don't assume that the junkyard part will be ok. You'll be tearing that SOB out and doing this shit all over again.

The soldering iron can be bought at Radio Shack for less than $20. Get the one with the smallest tip, maybe some thin solder too. A magnifying glass may help if you are as old as me. Keep us informed.

RexMan

My Holy Quest for Air Conditioning
 

Hey gents, thanks a lot for the help. I now understand that I'm supposed to reheat the points.

Also, I have already checked the compressor out, it's working fine. I have NOT looked at the receiver/dryer yet. Gotta get a meter first. The dog days are beginning here, and I'm on this project like stink on a monkey.

The small board looks ok, but the others look like they could use some touch up.

Sweet.

When I went through the CPU, Logicon, Clock, Stereo, & wiper modules, it took about 16 hours & fixed everything. Now that I know what to look for, it could be done in 8.

Okay, I just have one question: since I've never soldered anything before, how long am I supposed to hold the iron to the point? Above I read that the manufacturer doesn't heat the prong of the component, but just melt enough solder to integrate it into the circuit. So should I heat the prong, or just the solder around it?

Your problem might not be a bad Logicon. It could also be a bad air mix motor.

http://www.mazdatrix.com/in-logic.htm

Read.

Don't want to get you going in to many directions at once, but when you jumper the compressor and it engages with the motor running, do you see any bubbles or any activity at all in the sight glass that is mounted on top of that receiver/dryer? If you do see activity like bubbling, try leaving the jumper in place for say five minutes and feel for cool air coming out of the air conditioning vents. Now the real reason I wrote....can you please have the lass in the mirror turn around for a frontal look? (only half kidding).EDit......Yeah the air mix motor is a darn good idea. Gotta have some priorities though. Frontal look, air mix motor, logicon.EDIT......the air mix motor seems like a good idea except from my understanding, the air conditioning compressor will not engage unless he jumpers the wire going to it. What do you think?

RX7 climate control = 2 windows rolled down
 

Alright, I got myself a 15 watt soldering iron today, and I'm ready to attack the boards... except for the amp of course. I'll have to look up my air mix motor, I don't know exactly where it is.. yet.

Also, thanks for the info on checking the glass for bubblies, Hailers! I'll have to go check that.

By the way, the car seems to run just fine with no logicon in it at all!! aaahhh ha ha ha ha haaaaa!!!