Boss75

I recently noticed that the passenger side fan isn't coming on in my car. I have a switch hooked up to a relay for high fans and when I flip the switch the passenger side fan will come on. Otherwise the fan stays off. I did have a tune put on the car after I installed my cam and I'm curious if that would have anything to do with it? The tuner told me he programmed the fans to come on at 205 but I'm wondering if it's possible he only set the driver side fan.

Any help is appreciated.

Boss75

Thanks for the info 8vette7. I used this websites instructions to wire the high speed fan switch:

http://www.rangeracceleration.com/C5_Fan_Trick.html

I'll double check my relay 44 and also see if the driver side fan is operating in high speed mode all the time.

Bill Dearborn

I am guessing the Relay 45 terminals he is shorting together are the two shown in the schematic E3 and G3. All that does is provide constant power to both fans in serial mode and the driver's side fan in parallel mode. With only one fan running you either made the mod on the wrong relay or relay 44 is stuck in parallel mode.

There is a problem with running the fans all of the time. The ECM turns them off when the speed goes over 35 mph since air flow coming in through the bottom of the car is going faster than the fans can pull it through. If the fans are running they can actually reduce air flow through the radiator at speeds above 35 mph.

Bill

martysauto

Really good info posted by 8vette7 and Bill. All I would add is, the factory set up is good. There is no need to hot wire the fans, period.

Boss75

I only use the switch when I'm at the drag track and want the fans to run between hot laps. Also the fans were working fine after I installed the switch and only just recently the passenger side fan stopped spinning.

I checked everything again today because even with it being 102 outside the coolant temp was staying down around 205-210. The passenger side fan is working now without me touching anything so I'm going to see how long that lasts and look at it again if it stops.

Boss75

Just an update in case anyone else has this issue. My passenger side fan stopped working again today so I double checked my fuses. Relay 43 had a loose prong so I replaced the relay and everything works as it should now. Coolant temps went from 240ish back down to 210 or so.