240 A/C issue with 1991 245

My 1991 245 is stock with R12 still in the system. I have several problems that I think all track to one source. This car is my daily driver work vehicle. I'm in it from 7:00 to 3:30 every day. I work in town most days, and in Columbia it gets plenty hot. Working a/c is a must, so I need to fix this.

1: The a/c does not blow cold air when sitting still at traffic lights.

2: When sitting still or driving in heavy stop and go traffic with the A/C on, the car gets hot. I have not let the temp gauge get into the red. It gets hot and almost to the red. If I turn off the a/c it will stabilize at one temp. If I get moving so more air flows through the radiator it stabilizes and cools off. It does not overheat or get above the middle of the range at any time with the a/c off. It does not get out of the middle of the range with the a/c on when it is moving. Only in heavy traffic or sitting still.

3: When the car is moving the a/c works very good and blows nice cold air. I can't complain as long as the car is moving. Sitting still it's hot and sweaty junk.

4: When the car gets hot, it cools down very quickly when I get moving and more air moves through the radiator.

Here's what I've done to address the issues:

1: Bypassed the temp compensator board to eliminate that possible problem.

2: Flushed the radiator core EXTERNALLY with water to dislodge any debris.

3: Tested that the electric fan does in fact work by jumping the two red wires at the fan relay. The fan spins up nicely.

4: Jumped the two wires on the switch on the lower line by the radiator on the a/c system, which DID NOT activate the fan. I may not understand how this switch works though.

5: Checked that the mechanical fan clutch is not siezed. (again the car never runs warm with the a/c off no matter the driving conditions)

Here's my questions:

1: How do I rewire the electric fan circuit so the fan comes on at all times when the a/c is on?

2: The four wires at the relay are two red and two light brown / tan. How do I determine which is the signal wire to activate the relay?

3: The relay in my car appears to be non-original as the pigtail has been spliced in and the four wires on the pigtail are white. Will a standard 4 pin bosch cube relay work to replace the $80 original style relay?

Any help is greatly appreciated. Hopefully I gave enough info to help diagnose.

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Wait, are you removing the belt driven fan and installing a factory puller fan and relay? From 1992+?

Or what are you working with here. I got a little ahead of myself.

Staying all stock. Mechanical fan in the stock shroud and stock aux pusher fan in front of the radiator.

I would just run a relay and trigger it using the wire coming off the negative side of the snowflake switch.

If it is all stock now, you simply bypass the high pressure switch, the fan relay will follow the snowflake switch via the delay relay.

I think you may be dealing with two separate issues.

Tell us about your:

Refrigerant levels. Have you put a set of gauges on the a/c system?

Type of coolant and mixture

Age of radiator

What do you mean by saying the mechanical fan clutch isn't seized? Actually, if it were seized, it would pull more air. Over heating at a stand still is usually either a bad radiator (which I somehow doubt as it is OK when moving), a bad (slipping too much) fan clutch, or a water pump with worn out or rusted away impeller fingers. How's your water pump?

Wren said:

I think you may be dealing with two separate issues.

Tell us about your:

Refrigerant levels. Have you put a set of gauges on the a/c system?

Type of coolant and mixture

Age of radiator

What do you mean by saying the mechanical fan clutch isn't seized? Actually, if it were seized, it would pull more air. Over heating at a stand still is usually either a bad radiator (which I somehow doubt as it is OK when moving), a bad (slipping too much) fan clutch, or a water pump with worn out or rusted away impeller fingers. How's your water pump?

Click to expand...

I have not put any gauges on the a/c system. It cools fine when moving, but not when stopped.

The coolant mix is clear of debris and sediment. Using my old fashioned floating ball tester is reads good to zero degrees. It looks recent.

The water pump was replaced by the previous owner about 10K miles ago when the timing belt was replaced.

I believe the radiator to be original. I do not have any records of it being replaced in the stack that was given to me.

I tested the fan clutch by simply spinning it when off. It could be slipping, but I don't have a way to test that.

cleanflametrap said:

If it is all stock now, you simply bypass the high pressure switch, the fan relay will follow the snowflake switch via the delay relay.

Click to expand...

I tried jumping those two wires together and the fan did not come on with the a/c. Do they not need to be connected? Could that be the red flag that the fan relay has failed?

I know I'm obtuse, but I'm still not clear on how to rewire this circuit to force the relay on when the a/c is on. Is the best way to add a second relay for the two brown wires?

i had same issue in an old ford i had back in the day....

the thermostat was stuck open, and at idle it made everything warm, instead of coolant sitting in the radiator cooling off, then entering the engine when the tstat opens, it just made the whole system warm and perpetually circulating. Only when a load was on the engine and not moving,,,,ie compressor...hope this helps.

57plymouth said:

I have not put any gauges on the a/c system. It cools fine when moving, but not when stopped.

The coolant mix is clear of debris and sediment. Using my old fashioned floating ball tester is reads good to zero degrees. It looks recent.

The water pump was replaced by the previous owner about 10K miles ago when the timing belt was replaced.

I believe the radiator to be original. I do not have any records of it being replaced in the stack that was given to me.

I tested the fan clutch by simply spinning it when off. It could be slipping, but I don't have a way to test that.

Click to expand...

While it's impossible to diagnose over the internet, I would put another fan/clutch in it and see if that makes a difference.

If your a/c isn't working AND it's getting hot while stopped, that's a pretty good indication that you aren't getting enough air through the stack. Also, if the pusher fan isn't coming on, it may be that your pressures are slightly low due to a low charge of refrigerant. The fan is triggered by high pressures building up in the system. I believe that there is an auxiliary fan wiring diagram at www.volvowiringdiagrams.com

Sitting in traffic today it was hot, the a/c was on and the pusher fan was off. I think the relay is bad, but I'm not sure because of that stupid switch. If I splice the wires on the switch it should eliminate it, and that leaves only the relay, right? I think I need that switch on the pressure line out of the equation. Can I splice those two wires together to eliminate the switch? I want the fan on when the a/c is on at all times.

Is the compressor clicking on when its hot?

I didn't check that. I usually have the a/c on and it blows cold. Then I come to a long red light or get bogged in traffic and the air of the vents goes back to ambient air. When I get going and push air through the front end it puts cold air back through. I'm about to leave for church now, and I can check if the compressor is spinning at a red light if (HA HA HA) when it gets hot.

You already said temp stabilizes when you turn the ac off and creeps up when it's on, at a light. Then blows cold when you start moving. This information indicates the compressor is running. No part of the system will shut down the compressor at a light. There is no feedback from the transmission or speedometer.
Trying to solve an ac issue without knowing if you have a proper charge is like trying to solve a no start issue and you don't know if you have gas in the tank.

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OP where are you located, Columbia, MD, SC, MI, or ????

It's been a while, but you should be able to jumper the switch connector inside the right-had fender rail inline with the high side and get the fan to come on if the fan is good and you have a good relay with power going to it.

Look at this: http://volvowiringdiagrams.com/volvo/240 Wiring Diagrams/Volvo 240 1993.pdf

So the relay for the cooling fan was not wired correctly. I fixed that and the fan started working. I pulled the radiator out and it was clogged externally. I put in a new radiator and it never overheats.

Now the clutch on the a/c compressor has failed. So, I'm switching it out and converting to 134.