1993 volvo 240

Skymaster · Post by **Skymaster** » 20 Aug 2016, 19:13

Is there a way to add some wiring somewhere to be able to make the electric ac cooling fan come on with a switch inside the car, regardless if the ac is on or not?
Im in Florida and when the temperatures is very high, I would like to have an switch inside the car to make the ac fan come on to help the mechanical fan.
I appreciate any information on this.
Thanks
Guido

93Regina · Post by **93Regina** » 21 Aug 2016, 06:28

Skymaster wrote:Is there a way to add some wiring somewhere...

Buy a tropical mechanical fan clutch, and have your radiator cleaned.

Down by lower radiator hose is a AC high pressure switch...unplug...turn ignition switch on...turn AC switch on...wait one minute...place a jumper wire across two terminals on AC high pressure plug...does AC fan run?

Make sure AC fan's mounts are still intact...two of mine were broken.

Yes, there is a way to Jerry-Rig it...but getting a new fan clutch, and cleaning out radiator will assist in your situation. Getting a redblock engine hot will cause a head-gasket to blow, and maybe destroy your engine.

Penny wise, pound foolish

Skymaster · Post by **Skymaster** » 21 Aug 2016, 08:09

I will try that., Some of the posts say that a "Tropical" Clutch will shorten the life of the water pump and put more stress on the engine.
I just want to "Jerry-Rig" the system by adding a switch in the panel that I can turn the electric fan on at will.
That you for your replay.
Skymaster

I just wish working on this car would be as easy as working on a jet engine.

93Regina · Post by **93Regina** » 21 Aug 2016, 23:09

Skymaster wrote:I just want to "Jerry-Rig" the system

Piece of cake...I just explained how...Down by lower radiator hose is a AC high pressure switch, which activates AC cooling fan when AC pressure is too high.

You take out your butcher knife, and splice in a wire that activates the relay side. Don't splice into the hot 12volt wire...its the other side that goes to the AC fan relay.

PS: Relay must be working. My AC does not work, so I put a jumper clip there....I don't use a fan clutch, I have an e-fan on radiator side, and I'm using an older turbo radiator, which has a temp sensors on it. In stop/go city traffic, I flip on the AC switch

Jerry-rig - If your cooling system is inferior, AC cooling fan may or may not work. I paid over $100.00 to have my radiator cleaned, to be sure.

Skymaster · Post by **Skymaster** » 22 Aug 2016, 18:42

Hello
Pardon me., is it possible to send me (to my email: [email protected]) some kind of diagram of what you are talking about?
I really appreciate you taking the time to explain how to do it.
Thanks

93Regina · Post by **93Regina** » 22 Aug 2016, 21:00

Skymaster wrote:diagram

Item "F" is the high pressure AC switch that activates cooling fan, and is located on passenger side engine compartment, below lower radiator hose. "D" is the relay, and "G" is the AC-fan.

On relay pin 86, there is voltage there when your AC-switch is flipped on inside vehicle, and pin 85 is used as a ground to energize relay so fan works.

So, if your AC-switch is flipped on, grounding pin 85 will activate fan. But, if your AC-switch is not turned on, nothing will happen if you ground pin 85.

So, this setup only works if your AC is running...in my case, where AC is not working, I jumpered the high-pressure plug's terminal to complete its circuit; so when I flip the AC-switch inside vehicle, the AC fan will run within a minute...there is a time delay circuit, so when the AC-switch is flipped, nothing will happen until a minute or so has elapsed.

Only way to make AC-Fan run when you want it to run without AC running is to use a Bosch relay and get power via AC relay (terminal 30) or battery. My radiator fan is powered directly from battery, with a circuit breaker fuse on it. Someone suggested AC fan relay is located in LF of engine compartment, but I've never checked this out.

See this thread...lots of ideas.

Do note, this diagram is from late model 1993 240s, early diagram is a bit different in some ways. At the battery, do you have a fuse setup?

: Capture.PNG (168.86 KiB) Viewed 2451 times

93Regina · Post by **93Regina** » 22 Aug 2016, 21:20

So, which way do you want to power up the AC Fan?

1. Via AC Switch Only?

2. Independent control of AC Fan?

Skymaster · Post by **Skymaster** » 23 Aug 2016, 19:17

Thank you for the Schematic.
I want to rig it so I can turn the fan on and off independent of the ac.
So., I think that if connect the #30 and #87 with a fuse (25 amp) and bring the wires inside to a switch, If I close the circuit,
the fan should come on. if I don't throw the switch, the system operate normally.

Thanks a lot, I will let you know what happens!

93Regina · Post by **93Regina** » 23 Aug 2016, 21:27

Skymaster wrote:independent of the ac

Inside vehicle, I would ground one side of an installed switch, and run its other wire to terminal #85. Then at terminal #86 wire, I would install a diode, and place a hot-wire before it, via terminal #30's power.

A diode allows current to flow in one direction...so if you understand this, you know how to hook up this circuit.

Using a ground circuit prevents any electrical issues...at worse, the fan runs, if relay is working.

Skymaster · Post by **Skymaster** » 24 Aug 2016, 18:52

Reporting my finds for today.
Replace the water pump with a oem (Volvo ) water pump., Vernet 82C thermostat, Very clean Radiator ( no dirt on the outside).
Temperature gage goes up into the red. Jump the electric Fan (at the connector by the lower radiator Hose.
Temperature gage goes into the red.
I also turned the heater inside the car on (it blows hot air),
No change in the Temperature gage stayed in the red.

In reference to your diagram.... switch inside the car one end to ground other end splice into no.85., splice from 30 thru a diode to 86?
Thanks
Guido