funny buisness with rad fan ???

[bobbyspider]

first off i have a 90 ford festiva the motor is swaped with a single cam b6. ok so heres the story it was hot the other day and i went for a 30 min drive on the highway (no traffic) every thing was fine. but when i got off the highway and hit some heavy traffic after about 20 min my engine temp guage was getting way above normal. so i pulled off the road and noticed the fan was not kicking on, but for some reason when i put the car on accesory on the ignition switch it kicked on. then i tried turning it to the start position and the fan kicked off back and forth "accessory on" "start off" . so do i have the temp switch mixed up im almost positive we switched and used the sensor from the b3 (maybe thats the problem?) but yea this is verry weird and its getting into summer and its getting hotter and this is my dd so if anyone could help or have had similar troubles please let me know

-thanks, Bobby D.

[Safety Guy]

I'm not sure, but for a temporary "fix," unplug your thermoswitch so the fan will run on the default mode. Unfortunately, it will run all the time, until you plug it back in.

This may not work if some other wires are messed up.

Karl

[ejp2fast]

sounds like to swapped the fan thermoswitch (side of t-stat housing) with the engine temp sensor (in the head- at least on the B3)

[bobbyspider]

^ i thought about that too maybe i have them backwards, (which one is supposed to be the the smaller pluged one?) i have the larger plugged one on the right and the smaller plugged one on the left. is that wrong?

[ejp2fast]

i don't have it in front of me... but do this: when the ignition is ON (not started) when you disconnect the single wire on the t-stat housing (fan switch) the fan should come on... then when you plug it back it, the fan should go off. Then the OTHER wire goes on the other sensor/switch.

[ejp2fast]

looking back at your original post... these fan thermo switches only kick on (in my case) at 5/8 of the way from Cold to Hot on the engine temp gauge in your cluster....
see this thread:

http://www.fordfestiva.com/forums/showthread.php?t=6901

also thinking last resort would be your ignition switch cylinder is messed up

[Lil-Red]

dont most electric fans in most cars shut off during a start? It would make sense to me to have all acc. shut down during a start

[Roboskittle]

I think he meant to say he was turning it to Run not start.

[1988redfordfestiva]

I say one of your temp sensor under the intake isn't making the fan kick on b3 had the sensor 2 prong green or black and b6 also has it under the intake so i think your sensor might be the issue give it a shot your guess is as good as mine ...

[bobbyspider]

I think he meant to say he was turning it to Run not start.

yes sorry i mean the run position, the fan works when the key is turned to accessory but not when the key is in the run position.

[1988redfordfestiva]

yes the ecu turns it on for a short test while u turn to the on position. check and locate the the fan switch sensor its located under the intake on those its 2 prong black or green connector like the festiva its located on the passenger side of the intake this sensor tells when the engine gets hot so that the fan can turn on ...

[bobbyspider]

^ thanks ill check it out

[bobbyspider]

well my repost in the general section has been closed so ill repost my last response from ice racer:

ice racer:
Believe me, if it's overheating within 20 minutes of running, you've got other issues in addition to the fan not cycling properly. Those engines (b3/b6) run very cool if the thermostat is a fresh/known good one. Air in the system is another quick to overheat cause, and the oft overlooked tired/old radiator cap will let coolant escape prematurely. There's the old leaking head gasket situation, where it causes over pressurization of the coolant system, forces coolant out, and then you overheat. Ask me how I know.

my response:
^ all my fluids are still topped off. the car doesnt over heat easy i still drive it daily it only does it on very hot days and only after i drive it hard and for long distances (or for long periods of time 45 min to and hour) and then get caught in grid lock traffic. i tried a test: i drove the crap out of it for 45 min then stopped and let it idle for like 25 min then it started getting hot (i never let it get into the red either time) but no fan, so i turned it off and put the ignition to acc and the fan came on then i put it to run and it went off. the fan works and the switch works its just not kicking on in the run position on the ignition only when its in acc ????? its as if something is backwards a wire or the polarity of a wire i dont know