Another electric fan post

[Curious Hound]

I originally used the Volvo relays also. Don't remember why I got rid of them.

 

[BobSacamano]

@Curious Hound which wire do you use for fan to turn on with a/c? The black/yellow at the compressor or the purple wire at the clutch pressure switch?

 

[Curious Hound]

I'll have to look. The wire at the clutch isn't the right place because then the fan might cycle with the compressor. I think I intercepted the wire going from the controls to the low pressure switch. That would have power any time the controls are calling for AC operation.

 

[Curious Hound]

@Curious Hound which wire do you use for fan to turn on with a/c? The black/yellow at the compressor or the purple wire at the clutch pressure switch?

Here is one way to wire this circuit using traditional automotive relays.

 

[BobSacamano]

Here is one way to wire this circuit using traditional automotive relays.

Thank you so much. Please let me know which a/c wire you used when you get a chance.

 

[Curious Hound]

Thank you so much. Please let me know which a/c wire you used when you get a chance.

It looks like I actually used the black/yellow wire at the compressor clutch.

But, it would make a better installation if you use the pink wire coming from the AC controls. On my 93, that wire is easy to tap into right before the "Clutch Cycling Pressure Switch" in the engine bay. That us the pressure switch on the evaporator line on the passenger side of the engine bay.

 

[BobSacamano]

It looks like I actually used the black/yellow wire at the compressor clutch.

But, it would make a better installation if you use the pink wire coming from the AC controls. On my 93, that wire is easy to tap into right before the "Clutch Cycling Pressure Switch" in the engine bay. That us the pressure switch on the evaporator line on the passenger side of the engine bay.

Thank you. I've got it all hooked up except for the AC relay. Hardest part was figuring out how to fit the Sable fan/shroud on the 2.3 radiator. I let it idle with the AC on with temps in the 90's today. Fan kicked on at 196 degrees and cooled down quickly to 190. Took it out on the highway and it never came on. I bet I never even need the high speed. Looking at the 96 diagram, that Black/yellow wire has a diode in the circuit. Maybe that's why you used it.

 

[BobSacamano]

If I wanted to use this bicolor indicator light in the cab and have it turn green on low speed and red on high speed using the Volvo relay, how do you recommend wiring it? Would the red and green wires go with the high/low wires on the temp switch or on the wires to the fan? And the white to ground?

 

[85_Ranger4x4]

If I wanted to use this bicolor indicator light in the cab and have it turn green on low speed and red on high speed using the Volvo relay, how do you recommend wiring it? Would the red and green wires go with the high/low wires on the temp switch or on the wires to the fan? And the white to ground?
View attachment 132350

Sit down with a battery and a test light standing in for the fans and play with it.

They are a PITA to figure out, especially in the land where you are not just controlling two lights.

I have the same Daiertek switch but toggle style in mine, I couldn't get one color to switch. I wanted blue for fans on and red for fans off, best I could get was purple with fans on and red for fans off. I was switching on the ground side of my efan relays too.

 

[lowspeedpursuit]

Since the temp switch in the writeup is switching to ground, and the LED is common positive/discrete ground, can't you just tap the temp switch wires directly?

Unless high speed closes both sides of the relay simultaneously, in which case you'll get both LEDs/yellow.
In that case you'd want an NC relay opened by the high-speed side and controlling the LED's connection to the low-speed side.

 

[BobSacamano]

Since the temp switch in the writeup is switching to ground, and the LED is common positive/discrete ground, can't you just tap the temp switch wires directly?

I was wondering that too. So the white wire would go to switched 12V?

 

[lowspeedpursuit]

I guess so, right? It's got a plus on it.

Behold, MS Paint:

This is basically what I was thinking if just tapping the wires makes both color LEDs light up at once. But, I'll be the first person to admit branching electrical paths are confusing to me.

 

[BobSacamano]

So I received the dual color LED indicator light today. I thought I ordered the common anode model but this one was common cathode. So I connected the green wire to the green wire going to the fan, the red wire to the fan red wire (both after the relay) and the black to ground. Warmed truck up, low speed came on and the green light lit up. When it cooled down, the green light went off. Then I disconnected the low speed temp wire so I could get a temp of 215. When the high speed kicked on, the light turned red for a second, then turned green. I guess I'll be happy with this as I only wanted 1 bulb(1 hole to drill) , but I was kind of disappointed that it didn't stay red in high speed. Is there a fix for this?