86 TA tpi 305 automatic. Car runs normal temp untill I turn on A/C, then it creeps up and never drops. I have never let it go past 230 or 235 but im sure it would (20-25 minuites of ac = 235). The normal engine temp with out a/c on is 180 to 205 max. This ONLY happens with the A/C on. I have just now tried to use A/C. The single electric fan runs and cools it fine and runs the entire time while the a/c is on and the car overheats the same in stop and go OR highway driving. Also, the A/C does not get very cold till the engine heats up to about 170. The A/C clutch turns on and off till the engine gets warm to 170+ then it stays on and spins the whole time afterwards. Whats wrong?


COOLING DETAILS ARE:
I have a 180 thermostat, adjustable fan switch thats set to turn on at 185 with a radiator probe (the original fan wires are disconected and taped off.) My waterpump is new, heater core is new, radiator is new (ordered for IROC 350), approx 50/50 antifreeze mix. I have my air dam pieces intact and raidaitor hoses seem fine.

A/C DETAILS ARE: Probably original A/C system except for compressor. Removed old compressor because it would not spin freely somtimes, it jerked slowly then spun ok for a while, then jerked again like it was trying to spin (it had freon but did not cool very good) . I removed it and saw the a/c port and line that gets hot (high side?) was black and the port that stays cool (low side?) was clean. I used a small vaccum pump (less suction than a shop vac) to clean out system, replaced orifice tube filter and put a USED compressor on. The used compressor (84 camaro) was clean on both ports (no black) and I drained / vacumed out old 134A. I had to swap the electrical compressor conectors because they were not the same. The replacment compressor had a single wire type round connection that I had to switch with the 2 wire pin type connector that was on the old 86 TA compressor. Put 2oz of oil charge in and 2 12oz cans of 134a. Checked readings (ENGINE HOT 170+) at outside temp of 85 and the blue low side was at 44psi and red high side did not give a reading (bad connection?) Tried a reading when ENGINE WAS COLD and low side would max out quickly and then the compressor clutch turns on and spins, this lowers the reading to approx 50 psi and then the clutch would turn off and the psi would go up again to max and the cycle repeated itself again (till engine warms up). With the engine cold I got a high side reading of a steady 50psi. Since then I have not been able to get another high side reading cold or hot (bad connection?). A/C is cool, but not cold, I think it needs a little more 134a but dont see how this would cause it to overheat.

ALSO: ath the compressor the low side line gets moist + cool and high side will burn if you keep your finger on it. The high side near the service port is almost as hot and the evaperator gets wet all over and is cool.

 

Quick question here, I notice that you mention R134A. Did you do the R134A conversion on the system or did you just put the R134A refrigerant in it. Another question is how good is the air dam under the front spoiler?

 

The air dam is intact but is a little old and bent / wavy. It is bolten in place good and I also have the two upper side flaps that are supposed to keep you from losing airflow. The car ran approx 190 to 200max at constant highway speeds with a/c off. The car will get hot even parked when the a/c is on (and the fan seems to be running strong (it will knock a stick out of your hand and not slow down). I will have to take a long highway trip with the a/c off to test the cooling air dam results again.

also the car had 134a in it when I got it. But I doubt it was a profesional retrofit since the old a/c did not work good at all. I saw no conversion label but there was a 1/2 empty can of 134a quick charge in the hatch area. It also had a 134a fitting on the reciever drier.

 

The air dam pieces still work great. I took a 45 min highway test run at constant speeds of 65 to 75 and it ran between 180 and 190. I turned a/c on and it went to 220 in 5 minuites! A/C blew cool but not real cold. I turned a/c off and temp went down to 190 in 10 minuites and stayed at 190 for the last 20 minuites home.

Idea: is my car doing this because I do not have the original fan wires connected and the ac is trying to turn the fan on or something?


BTW: summer night with t-tops off = nice joyride

 

Let me check a couple of things and get back to you on it.

 

Thanks, you da man!


I found 5 old posts so far with the exact same problem and no resolution listed, I think all of them had electric fans and 4 mentioned that they had altered the wiring to make the fan run all the time or did so to rig up dual fans or some aftermarket cooling.

I think I will try and re-hook up the original fan wires when I get a chance this wednesday. This way I can do a quick test it with the original setup. It would at least eliminate that posibility.

 

I am anxiously awaiting an answer on this too. My 87 5.7 is doing almost the same thing, and I have not got an answer on my problem yet either. I have gotten some good ideas, but not hit the spot yet. The only thing that I haven't checked is the switch that is located on the head (I wished someone would give me some more details on this)
My problem is that the fan on the passenger side (which is the A/C fan) is not coming on, the fan on the driver side is cycling on and off correctly. When the car is moving and the temp is around 160-180 the A/C air blows somewhat cool, but when I get in traffic and the temp goes up the A/C air gets warmer. And as an added bonus, when the hood is up and I am watching the compressor kick on and off, right before the compressor kicks off the belt gets to jumping around like it is going to come off the pulley, I guess the pressure is building up. I have tried a new relay and that did not work. I can jump across the plug and make the fan come on, but it will not work on its own.
Please help us........its HOT!!!!

 

Barry bum, does your car run fine and keep the engine cool when the a/c is off? Does it only heat up when you turn on the a/c? will the engine start to cool off when you turn the a/c off?

I would check the fans to see if they are working ok. You could try my method of poking a stick at it to see if is stops or slows the fan down (if a small stick stops it or slows it down its almost dead). If one fan does not turn on try to unplug it and use 2 jumper wires to hook it directly up to the battery (test to see if it works) OR if the wiring is the same for the two fans try and use the wires to the good fan to the one that does not turn on to check it. If it does not work, replace it. If it works with the jumper wires but will not turn on you may have a problem with the wiring or relay or fuse or something else that is harder to find.
Ill let everyone know my results of re-hooking up the original fan setup.

 

Where in Kansas are you?? With the a/c running (clutch engaged) you should see low side pressures between 25-45 psi and high side pressures around 220-250 psi. If you aren't getting a reading on the high side, odds are that the wrong retrofit adapter was installed and the pin on the hose is not engaging the valve properly (buy a set of retrofit fittings at a part store (they sell them separately) to resolve this). Double check your ignition timing and make sure you aren't over-taxing the cooling system with the engine (making it too much with the a/c on).

Oh and one more thing: if the person who retrofitted the system originally didn't touch the clutch cycling switch, you won't get as good performance out of the a/c system as you deserve. If you have the low side pressure gauge hooked up, adjust the switch (the one on the back of the accumulator) to where the clutch will cycle off at around 20 psi (stock setting with R12 is around 25-26 psi). However, this might be a step after you've resolved the overheating problem, as it won't have much effect on that.

Ok, one more thing.. I'd like to steer everyone away from what I call the "ghetrofits". These magical retrofit kits that they sell at the parts stores for $30 are terrible. Do it the right way and be done with it. You can buy the port compressor o-rings, a general o-ring assortment, and a new accumulator and orifice tube (use the ford blue orifice tube for increased a/c performance) for less than it will cost to maintain a ghetrofitted, leaky, poor-performing system. Also, don't work on a/c without at least a low-pressure side gauge. I think I'm done now.

 

GOT IT!!!!!!!!!! This may or may not fix other peoples problems too.

I hooked up the original fan wires to the fan.... it didnt work at first.... so I checked fuses and I was MISSING the 20amp C/H FAN fuse (I didnt need this fuse before because I had my adjustable fan relay hooked up to an alternative key on power source). I put the fuse in and the fan worked like it should original. It kept the car around 205 to 225max with the a/c on max. I also noticed that my battery meter ran higher with everything running almost at 13. Before it would be at like 11. My GUESS is that the car needs the fuse AND the fan wires hooked up to complete a circut that helps the engine run cooler? Also I would guess that the incomplete circut caused the drain on the battery that gave me the reading of 11..... therefore there was not enough power to run the fan as good?

ANYWAY. I plan on keeping the original wiring hooked up to a fan AND use my adjustable fan relay setup to hook up a SECOND fan. I hope this will make it run cooler (and I can make the second fan come on earlier than the original)
I will have to remove the original fan because it is too big and hook up a smaller one to be able to squeeze 2 fans in.

QUESTIONS: what size fans would be best? 2 of the same size? OR should one be bigger than the other (which one?) AND should I make a plastic shroud to cover the rest of the exposed areas of the radiator, (does this help?)

 

I am in Lenexa, about 30 to 45 min away from Lawrence I think. PM me if you would be willing to help me sometime to make my a/c cooler. I also have extra parts I would be willing to trade or sell or give away if I dont need them.

Ok, the a/c is cool but not cold. I have no idea what the clutch cycling switch is or how to adjust? it? Please let me know.

Oh, and my ignition timing should be as close to perfect as you can get on a 130k original motor... stock 6btdc with an advanced timing analyzer so that should be ok.

And I agree that the quick ghettoFit 134a conversions are not the correct way to do it. I am just trying to see if I can get the free parts I have to work ok before buying all new stuff. $20 invested so far and an old compressor I had lying around and it works... kind of good

 

It runs at 190 now with the a/c on full blast. I made a fan shroud and cut a hole for the electric fan. It covered the exposed areas on the radiator. I used a single 14 & 1/2 electric fan. There is 1 & 1/2" space between the fan shroud and the radiator. This is the one change that made the difference. It helps suck the heat out. Oh and i also used pipe insulation to cover up the gap on each side of the radiator / front a/c piece. I think there is a tech article on this here called a/c strips.

In 86 GM was still using electric fans without shrouds. I think electric fans first showed up on a firebird in 84. The early ones I have seen came without a fan shroud. The newer ones and every other new car I have seen have fan shrouds. I think they realized after a few years that the shroud helps a lot.

I hope this helps other people keep it cool.