Guys,

I have a pacet 16 inch fan on my V mount setup which recently gave up - it overheated and shorted, and i think it was because i used to have it on all the time (it was wired so it worked when the air con is on, so i used to just leave it on all the time because i was lazy - car has no air con)

Anyway, long story short tonight i fitted a new rad fan and connected the negative to the black on the stock fan connector, and the positive to the white on the stock fan connector.

When the car hits 90 degrees the fan comes on (as set in the PFC) but i've left the car idling for 15 minutes or so now and it hasnt switched off. The temp is 84 degrees on the pfc...

WTF? Can anyone help?

Thanks

Bob

 

i am pretty sure i have your answer but will need to double check my shop manual and will get back to you sat a m if someone else doesn't answer your question.

hc

 

back to the top!

 

it appears you wired it o k. the white wire connects fan relay #4 w fan motor #2.

since it is wired correctly it appears that since you are now driving 2 fans thru a relay that is designed for one fan the odds are the relay is unhappy w the additional load and is stuck in the closed position. in theory after cooling off it should again work and then again overheat. you may need to add another relay and wire it to the trigger wire.

hc

 

Howard,

Thanks for the help bud, But i think i didnt explain myself properly?

I am only driving one fan now instead of two. On the stock rad you'd have one fan per connector and two connectors. Now i have one large single fan connected to one connector and the other one (a connector, that is) doing nothing...

When i switched the car off at 85c and directly back on again the fan stopped when i shut the car off, and stayed off until the car hit 90 again, then it would not switch off again until i switched the car off....

Even with a multi meter and no fans connected at all, im still getting +v from that white wire at 84 degrees, but ONLY after the fan has come on.

If i go out there now and start the engine, there is no voltage at any of the terminals on either fan connector. At 90 degrees, the white wire on both connectors goes +v and stays that way until you switch the car off it seems... So i can't even wire another relay in!

Very odd. Can anyone tell me which of the 4 relays is the one that switches on when the thermoswitch triggers? I only have 1 fan so only really need 1 speed and 1 live so i can just ditch the 4 stock relays and wire my own single one in... problem is finding the signal that is +v at 90c + and neutral at below 90c....

Thanks for any help anyone can provide.

 

I can't be of much help but I have seen a thread on here that had the wiring diagramed of how to install an aftermarket fan using the stock wiring and control systems. Might want to search for it.

I burned out 2 sets of stock fans from running them very often (engaged at 85C) when I had a FMIC. Now that I have a Vmount, I increased the temps at which the fans engage since my temps w/o fans normally stay in the 80-89 C range depending on ambient when there is air flow. The only time I need fans is in stop and go traffic now with the Vmount. I set the low fan to engage at 89 or 90 C and it rarely surpasses that temp even in 90 F ambient temps

 

relay 3 triggers w the thermoswitch. a blue and orange wire to the fan motors.

 

Just to clear this up...

The wires i had them in were the right ones, Black for neg and white for live.

The fans will come on at whatever your car is set for (90 degree on mine, 100 i think stock) and when it dips below a certain temp they will go off.

My fans go off at 84 degrees, but car sat still at idle runs 85 constant. I think the colder coolant wasnt getting to the temp sensor quickly enough at idle because of the low revs involved - when im driving the car around the temps are constnatly 83 or 84 for normal driving.

fan starts up in traffic and shuts down when your moving around just fine.

 

Simply set the fans to turn on at 93c or higher. As I understand it the PFC will turn off the fans 10c below the on point. If you have it set the on point at 90c, then the the off point is 80c and the thermostat doesn't even open till 83c.

Paul

 

i know this is a old *** thread but what if instead of using the black wire to ground it you use the blue and orange wire that goes through the the relay thats controlled by the thermo sensor.