Manual fan switch question

[firebaron90]

Hey all,


Question: To set up a manual fan switch on the 89 SMEC electronics, I know you have to run a grounding wire from the fan relay's single blue wire plug to a heavy duty toggle switch. I have also heard that if you have removed your A/C system from you car, you can do and easier and slicker method, which is to pull the plug out from the side of the aluminum block where the A/Choses ran into the firewall, and jump the two wires in that plug. Then, when you hit the A/C button on the heater console, the fan will turn on and stay on until you hit it again. Is this true??

Joe

[BadAssPerformance]

When I run a toggle I usually just wire a secondary 12V supply from the battery thru a switch and dedicated relay.

I have heard the A/C mod as well for use on cars with the A/C removed, not exactly sure on that one tho.

[firebaron90]

Thanks for the answer JT. No one has ever done this?? Hmmm, i think I will have to try it.

Joe

[BadAssPerformance]

No problem.

Someone was talking about doing that but I dont remember who :(

[Tony Hanna]

http://www.turbo-mopar.com/forums/showthread.php?t=6432&highlight=switch

Theres a discussion about it in that thread. From what I can tell, it's pretty hit or miss as to wether or not it'll work. I think you may have to throw some resistance in line with the compressor clutch plug too. An 1157 bulb with both filaments wired together might do the trick. Of course a resistor with the same value as the compressor clutch would be ideal, but everybody has tail light bulbs laying around.:)

[SteveReject]

I just have a switch to ground out the blue wire from the relay under the hood. I used speaker wire and installed the switch in the plastic piece that the convertible top switch is on. When I turn the switch off, the computer retains control of the fan.

[turbovanman²]

I did the ground one as well, simpler, no relay and yep, computer control in case you forget, :D

[BadAssPerformance]

Yeah, computer control is great, I wire them in parallel so the computer can still turn them on ;)

[TurboRon25]

I've done the A/C wire jump thing in many cars. Love it and no problems. The only thing is in an all weather driver I'll take it out in the winter because the fan will also come on when you have your HVAC controls set to defrost the front window. I just don't like the idea of the fan running constantly on those cold damp days. I use whatever junk scrap wire that I can find lying around about (1.5" of it), and shove it in the connector (on cars that still have the block I put the plug back on the block to keep that stock look). I like it better than having a toggle switch or something. Race cars have switches, my cars are stock!

Ron

[BadAssPerformance]

I knew one of the local guys had done this, just forgot who :thumb:

Ron, you gonna write up a little newsletter article with pics for how to do this fo rthe club newsletter and TM knowledge center here? ;)

[Tony Hanna]

I've done the A/C wire jump thing in many cars. Love it and no problems. The only thing is in an all weather driver I'll take it out in the winter because the fan will also come on when you have your HVAC controls set to defrost the front window. I just don't like the idea of the fan running constantly on those cold damp days. I use whatever junk scrap wire that I can find lying around about (1.5" of it), and shove it in the connector (on cars that still have the block I put the plug back on the block to keep that stock look). I like it better than having a toggle switch or something. Race cars have switches, my cars are stock!

Ron

Did you still have the wiring for the compressor clutch plugged in?
I remember reading somewhere (I think it was in the thread I posted the link to) that some people were having trouble getting this trick to work and it was mentioned that the compressor clutch not being connected might be the problem.

[TurboRon25]

Most of the cars didn't have a compressor anymore. And those that did, I unplugged it just because I wasn't really sure exactly what made the compressor clutch engage and didn't want to have any issues with it deciding to engage (esp with a locked up compressor).

I've had to stock pile some junkyard switches because a few didn't work anymore. Usually you can hear a better "click" from the good ones. Push on a good one and a bad one and I bet you can feel the difference.

Ron


Did you still have the wiring for the compressor clutch plugged in?
I remember reading somewhere (I think it was in the thread I posted the link to) that some people were having trouble getting this trick to work and it was mentioned that the compressor clutch not being connected might be the problem.

[TurboRon25]

I was thinking about stuff like that. ....with my new position and all. Yes, I should have a more normal life again soon.

Ron


I knew one of the local guys had done this, just forgot who :thumb:

Ron, you gonna write up a little newsletter article with pics for how to do this fo rthe club newsletter and TM knowledge center here? ;)

[Tony Hanna]

Most of the cars didn't have a compressor anymore. And those that did, I unplugged it just because I wasn't really sure exactly what made the compressor clutch engage and didn't want to have any issues with it deciding to engage (esp with a locked up compressor).

I've had to stock pile some junkyard switches because a few didn't work anymore. Usually you can hear a better "click" from the good ones. Push on a good one and a bad one and I bet you can feel the difference.

Ron

Thanks. Might have been bad switches in those cases then.

[BadAssPerformance]

I was thinking about stuff like that. ....with my new position and all. Yes, I should have a more normal life again soon.

Ron

Sweet! :thumb:

[91DSX]

Hmm, this did not work for me, A/C completely removed? So the switch is bad?

[Clay]

didnt work for me either, but a write up would be GREAT!