Adding a Manual cooling fan switch - easier way.

[Alfisto Steve]

Just added toggle switch to Quik Silver II to turn on low speed cooling fan without even opening hood to do it.

When I did the dash replacement on Rosso II last month I found connector G150a located near hood release handle behind wiring harnesses under fuse box.

It is a 2-wire connector with pink wire from cooling fan F14 fuse in G1 main fuse box going to pink-white wire going to power energizing coil of low speed relay. I left those two wires hooked together in G150a plastic connector.

The other wire is the brown wire that grounds the low speed relay so all I had to do was add an extra black wire with spade connetor to connection point of two brown wires (I took them out of connector) and I ran this new wire to a Radio Shack toggle switch and run another black ground wire from toggle switch to ground under steering column.

I mounted toggle switch in spare hole in lower steering column cover.

I may still add my green light mod to show when fan is running and my after run mod so fan runs to lower Freon Pressure and radiator temp after car shut off but will have to go under hood again to do those mods.

[alfahill]

I have done this same wiring splice for the fan, but added a green light, placed inside one of the block off plates where the sport and auto switches are for the 164S. The switch grounds both the relay and the light at the same time. The light is very useful because I often forget I left the fan switch on. I put the switch under the steering wheel too, so it is not visible and easy to forget without the indicator light.
On my LS, I used a lighted switch in the center console in the slot next to the power lock switch. Now, I can see when the switch is on, because it lights up when the fan is turned on.

[Alfisto Steve]

What I did will work fine for just turning on low speed fan BUT it prevents one from wiring up the after run mod using low speed relay so fan will shut off by itself after system cools off. Because if you leave manual switch on relay just stays energized even though key is off because after run mod has to have constant power to relay coil and thermal and trinary switch controls grounding of relay SO manual switch negates those switches.

I will either have to rewire manual switch to operate high speed relay only or install after run mod to high speed relay instead.

[daytona90t]

Hi Steve, Steve here. I was planning on trying a few of these cooling fan wiring mods this weekend, now there are more option to choose from? good grief. Question is, if I have the low speed resistor bypassed (brown and blue wires crimped together) and I do the after run mod to low speed fan relay as you have described in another post will the after run mod work the same just at high speed? I am asking because I am planning on getting a new low speed resistor and adding it back into the circuit eventually and I don’t feel like having to rewire the after run mod again. Secondly if I do run the after run mod into the high speed relay directly after run fan will be on high speed regardless, will that then allow me to wire the manual switch as described above in to the brown low speed wire and get the high speed fan to work if I leave the slow speed resistor out of the circuit? If it sounds like I have just confused my self could you let me know how if at all not having the low speed resistor in the circuit changes any of these mods. Thanks Steve

[Alfisto Steve]

Quote:

Originally Posted by daytona90t Hi Steve, Steve here. I was planning on trying a few of these cooling fan wiring mods this weekend, now there are more option to choose from? good grief. Question is, if I have the low speed resistor bypassed (brown and blue wires crimped together) and I do the after run mod to low speed fan relay as you have described in another post will the after run mod work the same just at high speed? I am asking because I am planning on getting a new low speed resistor and adding it back into the circuit eventually and I don’t feel like having to rewire the after run mod again. Secondly if I do run the after run mod into the high speed relay directly after run fan will be on high speed regardless, will that then allow me to wire the manual switch as described above in to the brown low speed wire and get the high speed fan to work if I leave the slow speed resistor out of the circuit? If it sounds like I have just confused my self could you let me know how if at all not having the low speed resistor in the circuit changes any of these mods. Thanks Steve

[multicam]

I'm going asked a ignorant question.
Why is this modification important? I am not aware of any problems when I shut down the car after a long or short trip. Is this modification more important in areas of the country where their are higher ambient day time temperatures?

[Alfisto Steve]

Quote:

Originally Posted by multicam I'm going asked a ignorant question. Why is this modification important? I am not aware of any problems when I shut down the car after a long or short trip. Is this modification more important in areas of the country where their are higher ambient day time temperatures?

[goats]

I think this mod is a reasonable attempt to, as Steve says, reduce coolant temp in radiator and reduce freon pressure. To what degree it does this is unkonwn but theoretically it should work.

The question remains, though. So what? Why would I want lower coolant temps in the rad after shutdown and lower freon pressures?

I think the answer is-- its a matter of personal preference! I do not know of any condensor 'blowing up' because the freon pressure is too high! I also do not know anything about risk/benefit of lower coolant temps in the radiator at the price of having a 20 amp circuit running in the car when I might not be there to smell smoke!

NOthing wrong with the mod! Do it if you like, don;t do it if you don;t!

[Alfisto Steve]

To answer your question(s) it reduces freon gas pressure down to about 175-200 psi and coolant temp in radiator down to whatever low side of thermal switch is set at so a stock switch maybe 195F.

As for fuse 40A fuse bar for fan motor but 7.5 (91-93) and 10A (94-95) for relay control.

As for why - example we were dead stopped in a traffic jam on interstate with a Range Rover this summer and had engine stopped but the heat rise in engine compartment blew a/c hose and ester oil in freon from system hit exhaust manifold and we thought we had an engine fire starting. Roadside Assistance guy helping another motorist nearby change a flat came running to be sure we were OK. Man o man did it make smoke.

[goats]

perfectly reasonable steve and I will betcha that the ester oil on that manifold not only smoked like you-know-what -- but smelled like that too!!!!

Me, personally, I would not have anything like a 5A fan running with me not there. Call me paranoid I dont care. Have seen way too many burned up harnesses, connectors, etc --Just this last week the connector to the compressor on my refrig in the kitchen literally burned up, melted, etc -- it happened at 3AM and I woke to the smell of burning insulation. Fearing a house fire, I went and turned off all breakers -- but could not isolate where the smell was coming from! After a while I took the back of the fridge off and saw the literally burned, blackened, connector -- it DID NOT trip the breaker in the fusebox !

So a chacon a son gout and if you like the idea of cooling that hot engine down after shutoff, by all means do it! Its a good approach to solving that -- good job Steve. If youre a scaredy cat like me take a pass on it -- either way I don;t think you'll get into trouble unless ... youre driving with Steve and you get stuck in a traffic jam!!!!!

[alfahill]

I never set up the post shut-off fan, but the manual switch for the low speed fan has been very worthwhile. I always turn it on when in slow traffic, so the temperatures are usually under control when I turn off the car. As to the effectiveness of the manual switch, my '91 164S with 90K miles has all original fuel hoses and injector plugs that show no sign of cracking or deterioration. All the rubber and plastic parts under the hood look great and I have over 70K miles on an original Alfa serpentine belt tensioner pulley that I installed when I first got the car.

[goats]

the manual override is an EXCELLENT idea I think.

[multicam]

Thanks guys, I see the benefit now. So, throwing this switch will let the fan run on low till it's turned off by the operator and not automatically. I get it now.
Thanks

[Alfisto Steve]

Quote:

Originally Posted by multicam Thanks guys, I see the benefit now. So, throwing this switch will let the fan run on low till it's turned off by the operator and not automatically. I get it now. Thanks

[daytona90t]

I finally got a chance this morning to wire up a manual fan switch and a fan on light here is how I mounted my switch and LED light. I was a little apprehensive to start cutting holes in my dash but I am happy with the way it came out.