fan not turning on

[89boostedminivan]

previous owner had the fan turning on and off by a switch he mounted under the dash, the switch is wired up to a relay rite above the pcm on the drivers side fender under the hood, i dont see any wires disconnected , how do i get the fan to kick on at the factory temp again?? were would i look for something to be unplugged possibly??

[turbovanman²]

In a nutshell, you have a rad fan relay, the computer grounds it thus turning on the fan. If you see wires going to a manual switch, he could have just unplugged it and used the switch. I will look at my van in the AM and let you know which relay is the rad fan. You have A/C, right?

[mark]

to make sure the wiring/relay and everything is ok... pull the temp sensor plug off at the thermostat housing, the same one you pull to set timing, if the fan turns on, then the relay is good. then your sensor is bad. if the fan does not turn on, when yu pull the plug, then you have electrical to track down... hope this helps a little

[89boostedminivan]

it had a/c, doesnt anymore. heres a pic of the relay were the switch is running off of, its tapped into a blue wire with black connector , the plug next to it with the white connector has the lime green wire that is going to the fan. i unplugged the sensor on the side of the tstat and turned the key on and no fan came on?? without having a temp gauge to know would running the fan the entire time im driving be to cool or just switch it on when stopped until i can get it fixed back to stock settings

[mark]

unplug the sensor connector when the car is running. as if you were going to set the timing on an 8v

[89boostedminivan]

can i unplug it then start?? never did the timing on a 8valve,loL!

[JDAWG]

really you just need key on. I would hook up all the wires back to factory. You could jump power right from your batt to the fan to make sure the motor is good. The puter grounds that blue wire to engage the relay. You could tap into that and run a wire inside the car to a switch then ground the other side of the switch, that way the puter still controls the relay but you can turn on the fan whenever you want

[89boostedminivan]

i know the motor is good cause i can turn it on by the switch, it looks like its all hooked up factory still, he just jumped off it with a switch, with that plug unhooked on the side of the tstat and van running fan does kick on??

[JDAWG]

if you pull the plug off of the sensor in the tstat housing does it turn on?

[89boostedminivan]

yeah, so im assuming the sensor itself is bad??

[turbovanman²]

They did the good old manual trick. That blue wire is the ground for the relay, so when you ground that wire, it turns the relay on.

Start the van or turn the key on, then unplug the coolant sensor at the thermostat housing, if the fan doesn't turn on, then you need to start tracing. A scanner would be a good start if you can borrow one. If you unplug it, you should hear the relay click, if you don't, its possible they cut one of the wires going to the relay-IE the blue wire.

[89boostedminivan]

well if i turn it on and unplug the sensor the fan does come on?? is the sensor bad or... cause without a temp gauge i dont know how long it can idle without starting to overheat. i watched it for a good 3,4 mins after already being warmed up and i didnt see the fan kick on so im assuming its not turning on how it should? if its turning on with the sensor unplugged does that mean it should be kicking on by itself??

[turbovanman²]

well if i turn it on and unplug the sensor the fan does come on?? is the sensor bad or... cause without a temp gauge i dont know how long it can idle without starting to overheat. i watched it for a good 3,4 mins after already being warmed up and i didnt see the fan kick on so im assuming its not turning on how it should? if its turning on with the sensor unplugged does that mean it should be kicking on by itself??

Ok, please read carefully. Unplugging the sensor causes the computer to go into a "backup mode" so to speak, it lets you set the base timing and turns the fan on so this part does NOT indicate a bad sensor quite yet. If you do this and the fan comes on, your computer, wiring, relay and fan are working properly. If IT does NOT come on, then you need to start diagnosing but you say the fan comes on when you hit the switch, meaning that it most likely should work or they cut the ground wire to the relay.

Now, if all that works, then you really need a temp guage to go further as the factory sets the fan on control really high, aprox 220 degs so it will seem like forever. If you are willing to gamble, let it idle and have a hose nearby, that way if the fan doesn't kick on, you can hose the rad down to cool it off when it starts to boil over. If all the above checks out AND the fan won't turn on by itself, replace the coolant sensor.


Why doesn't your factory guage work? Is it gone?

[89boostedminivan]

changed the sensor and it works!! i was 2 secs away from hitting the manual switch and it kicked on. as for the stock gauge?? the only thing in the van is a light that says temp?? which i assume lights up at the beg of overheating, i dont see were there would of been one factory so guessing it never had one? possible this van wasnt factory turbo?? would it of had a boost gauge even stock??

[turbovanman²]

Sweet.

Stand at the front of the van, look to your left, under the #2 spark plug, there should be a one wire sender in the head? if so, then you have the wiring, just get a turbo cluster and plug it in, you'll have a temp guage, tach, charging and maybe oil pressure.

No vans got a stock boost guage.

[89boostedminivan]

yeah there is 1 wire rite under #2? i do have a charging gauge stock, but i can tap into that line for the others then?

[turbovanman²]

yeah there is 1 wire rite under #2? i do have a charging gauge stock, but i can tap into that line for the others then?

You have a charging guage but no temp guage? can you take a pic of your cluster?

You can tap into that but the stock guage is more than adequate. You would have to trace the wire inside the cab and then cut into it, replace the sender. I did this for the oil pressure guage-it shows a boost guage as I was making it but now have an oil pressure gauge, looks stock-

[89boostedminivan]

do you know at what temp that lite would kick on??

[turbovanman²]

Weird, I thought all turbo Mini's came with the full guage package.

I would guess the light comes on at around 230 ish.

Just swap a full load cluster, then you have all the guages,

[cordes]

Weird, I thought all turbo Mini's came with the full guage package.

I would guess the light comes on at around 230 ish.

Just swap a full load cluster, then you have all the guages,

The fan doesn't kick on until almost 230. I would think the light would come on at about the time the HG blows.