Jk_Under

I have had problems with my a/c since I got my car. It blows nice cold air, and the heater works great, problem with the heater is that it starts blowing normal temp air out after a while.

When i run the cold a/c, my cars temp starts to raise after driving around with the a/c on for aprox 25 mins? I will just take a quick look at my gauges and see my cars heat is in the red, it returns to in the normal after i shut the a/c off and drive more.

When i switch my a/c or heater fan speed from off, to anything such as defrost or max, the cars RPM will drop, then return to normal at random times, frequently.

Can anyone suggest what to do to fix this? or tell me whats causing this, much appreciated!

one92rs

iTrader: (5)

the rpm,s will drop a little. the ecm is suppose to bump the idle approx 25 to 30 rpm's when the a/c is turned on. maybe something is drawing amps. check between the radiator and the condensor to see if there is build up of trash in there. the other thing to check is the evaporator to see if it is clogged as well.

Jk_Under

Where is the condensor and evaporator located? im really not familiar with those parts, and my cars engine has been messed around with, some things are out of place, from the previous owner when i bought the car. i'm getting around to restoring the car to a better condition.

Jk_Under

another thing, my rpm doesnt raise 35-40, it drops near a hundred rpm(guess, rpm gauge is not working)

one92rs

iTrader: (5)

the condensor is in front of the radiator. the evaporator is under the top cover where the a/c box is on the firewall. if you look down a few posts there is a thread where they explain exactly how to remove the evaporator.

rsmith085

iTrader: (1)

RPMs will drop on mine to. The compressor cycles on and off on these cars as a form of capacity control. In lay mans terms it keeps things from freezing up. As for the overheating stock fan sucks get a aftermarket one or go with the Ford Taurus fan. My car would run 230 with the AC on till I upgraded the fan

rsmith085

iTrader: (1)

Oh yeah goto home depot and get a can of AC coil cleaner and clean the condenser with it. It'll help a bunch......

Jk_Under

it only overheats when i turn my ac on, and what year model ford taurus?

rsmith085

iTrader: (1)

Yep that's the only time mine would overheat as well. It could be a 100 degree day and the car would cool good enough but as soon as I turned on the ac it would climb to 230 and just stay there unless I was going 70mph down the interstate. The reason it does this is ac works by removing heat from inside the car and then transfers that heat to the condenser. You'll also add heat from the compressor compressing the refrigerant and all this heat gets removed via the condenser coil that sits in front of the radiator. Anyways the Ford fan came on the mid 90's Taurus look for one from a 3.8 V6. The one I'm using came from a '95 Cougar and has a monster 18" fan blade that moves a serious amount of air. If I remember right the Taurus fan has a 17" blade and the shroud fits our radiators better than the Cougar fan. I had to modify the Cougar fan as it was to thick and hit the water pump pulley. I posted a schematic on how to use both speeds using 3 relays, now I'm running it off the PCM with some custom code. You can use the stock wires and relay to run low speed just fine and low speed on this fan is quite an improvement over stock. For the high speed you need a high amperage relay and if you put the relay close to the battery so the wire run will be short 10ga wire works just fine, I've seen people use 8ga but as short as a run as I have 10ga is fine. Anyways here's the link https://www.thirdgen.org/forums/cool...d-2-speed.html and google Ford 2 speed fan and you'll find tons of info where they've been put on everything from Z cars to peoples tow rigs.