GLT1

okay i found out that my primary and secondary are not comming on when they are sposed to,i let the car idle till about 235 degrees and neither fan ever came on, is there a sensor that activates the fans or do i need to reprogram?

Formula350

iTrader: (3)

The temp sensor in the water pump tells the computer what temp the motor is and the PCM then turns on the fans. So it could be bad, but you'd probably be getting bad gas mileage too. Could also be the fan relay (cheaper to test) not working anymore, giving them power. Swap a relay out somewhere else and try it in the fan's spot. Otherwise, to test the motors, just jump 12v from the battery to the positive on the fans (Don't forget to ground, and ground the proper wire too, 3 wires on yours (I believe) for being 2 speed fans).

GLT1

I checked the relays and they are both working,the fans are 1 speed, two speed are for 95 an d up i believe. I turned the ac on and only the primary goes on,and when it reaches 226 and higher no fans come on,

Formula350

iTrader: (3)

Well oddly the secondary + primary I thought comes on when the AC is on...

I'm no PCM guru (since I have an ECM) but I'd think it'd be something screwed with the PCM then. Or the sensor in the water pump. That's only $8~ and much cheaper than getting a new PCM

bobdec

GLT1, take a look at this schematic from shbox site its' a 1995 but I believe similar to the '93 " http://shbox.com/1/fan_schematic_1995.jpg " I believe the '93 one speed fans uses the top setup of two relays, later year two speed fan setups have three fan relays. With stock settings your primary fan relay should pick with a ground from the PCM at 225* F (107 C) and run fan 1 at high speed, the secondary should pick at 235* F (113 C) and run fan 2 at high speed. Also the A/C pressure sensor will tell the PCM to pick the primary fan if the AC is functioning. If you are loosing both fans at 226 with A/C running then as Formula stated it could be the temp sensor in the wp or the PCM is killing one or both fan run circuits, or your +12v to run fans from the fusable link +12v distribution block on the pass fender is opening under high current. You can attach 2 thin 5-6 inch wires to the pick side pins of the relays. reinsert the relays, turn on ignition and ground the wires one at a time or both at once to check relays, fans, wiring and voltage sources. relay D pin 2 and relay 3 pin 5 to ground will run the respective fan. I only recommend this if you are comfortable with reading schematics or working around live circuits.

Formula350

iTrader: (3)

A lil juice every now and then isn't a bad thing I don't even think our cars have enough of the right current (amps I think) to even kill us.

Anyways, Bob provided some solid info. Hope that helps.

GLT1

Well,i might run the fans through the fuse box,but i want to see if i can fix this to factory specs.Other than the water pump sensor,what is the sensor in charge of activating the funs based on the temp gauge on the dash?

Formula350

iTrader: (3)

Nothing. Temp gauge in the dash has it's own sensor, and that sensor ONLY outputs a signal to the gauge, nothing else.

blubyu02

iTrader: (17)

hey formula 350 why would it be getting bad gas mileage if the temp sensor in the water pump is bad? just curious cuz i noticed my fans not kicking on when the ac is off and that it took me damn near half a tank to get 33 miles to work.

Formula350

iTrader: (3)

Yea, it'll hurt mileage since the computer doesn't know wth is going on with outside temp. The one guy on here is a great example. His PCM thought it was 30 below and was just DUMPING in fuel. Mind you, they all die in different ways, and yours seems to be maybe just malfunctioning right now heh Who knows really, unless you hook up a scanner and see what it's at.

blubyu02

iTrader: (17)

i had my scanner hooked up to it and it was dead on accurate pretty much the needle was at 210 and the scanner said the car was at 208. it has a cylinder misfire for sure tho cuz it needs new plugs and wires im hoping thats all it is. but are there any other temp sensors on a car besides on the waterpump? and sorry didnt mean to hi-jack thread just having same problems.

blubyu02

iTrader: (17)

also i let the car idle with no ac on and it got to the 3rd white line right before 260 and still no fans had kicked on. i cut the ac on max and the temp went down between the 1st white line and 210.

Formula350

iTrader: (3)

Probably should wire them up to a switch in the mean time.

blubyu02

iTrader: (17)

i thought of buying the one from slp but when im driving it sometime it still goes up past 210 with the ac on in town but goes down on the highway so im ordering a 160 therostat and going to get a tune on it hoping that may help it.

blubyu02

iTrader: (17)

i drove the car and it got to the 3rd white line and it stayed there even with the air on and on the highway something is either clogged or not passing water like it should i bet.........

DarkKnightRider

gotta remember that when your in town idling even with the fans on there isnt alot of air moving through the radiator. cruising on the highway though. lost o air through it.

Formula350

iTrader: (3)

If you think it's clocked chck under the bumper for paper or plastic.

You can make your own fan switch if you know how to wire things up. I'm sure a diagram on ShoBox.