overheating rodea, front fan wont come on

I just ran out during lunch and noticed my temp gauge pegged at the high mark when i stopped at a red light, given i was in downtown traffic and there was no place to pull over to i had no choice but to keep going. Once the light turned green and i got moving maybe 30 miles per hour the temp started going down to normal, i played russian roulette with the stop lights trying to get back to work and i made it without it pegging the high line again. Here at work i noticed the front fan is not kicking on and i checked to make sure it was functional by hooking up 12 volts to it and the fan worked fine so it has to be whatever switch tells it to turn on thats not working ,Where is that switch? Also i checked the fuse and it is fine, any ideas?


By the way this is a 96 isuzu rodeo , i allmost forgot to mention that.

It could be the fan switch. Or maybe there is a clog in your radiator. Get the rad, flushed and pressor tested asap. depending on your miles, your rad may need to be replaced.

one problem i dont know where the switch is , as far as the radiator being clogged i dont think it is becuase i did a flush not to long ago ( maybe two months ago ) However i did just check the fluid level and it took almost a gallon to fill the radiator and overflow resevoir so now im wondering where the fluid went, geez does it ever quit with these demon rodeo's?

Anybody know where that switch for the fan is?

Also on a side note anyone kow anything about the heater blower motors on these things? Mine quit working over the summer , one day it worked the next day i tried it and got nothing, i would think if the motor had gone bad then it would have at least blown a fuse or something but nothing.....

I thought that front electric fan only came on when the A/C was on? The mechanical fan should be good enough to keep it cool unless it is really hot out.

Its not really hot out , id say its somewhere in the upper 70's here. As far as the fan coming on then i thought it came on when the vehicle hit a certain temp. I know one day i was leaving work and a guy commented on how slow the fan was turning and i explained to him that it was just turning from the air coming off the other fan it did always stay on , just as i was telling him that the fan kicked on. I know i didnt have the AC on that day because the blower motor in my rodeo hasnt worked in months .

Can anone answer these questions:

1. Does the electric fan just come on during certain temps or is it only used if the ac is on?

2. Where is the sensor or switch that tells the fan to come on?

3. where did the 3/4 gallon of coolant go if i dont have a leak and my oil is water free?

Sorry to be such a pain guys this rodeo has driven me nuts lately.

fan will come on according to temp however if the A/C is on the fan should be on.

coolant temp sensor sends a signal to the PCM which in turn will activate the fan relay for fan operation

if you have lost that much coolant and you see no leaks it must have gone through the exhaust pull the plugs look for a hint of green on the ceramic if it is green you are burning the coolant out of it

Ok so far 3 replies and yet not one of them tells me where the temp sensor for the electrical fan is , does no one know?

Ok so far 3 replies and yet not one of them tells me where the temp sensor for the electrical fan is , does no one know?
Get a manual then! :iceslolan Like 2eye says, the elec. fan gets it's on/off signal from the PCM, which gets it's signal from the engine coolant temp sensor. The temp sensor is *usually* located near the thermostat neck. Trace around where the upper radiator hose goes into the engine. Coolant temp sensor should be around there.
G/luck
Joel

I have a manual on the vehicle however there is no mention of the sensor that i can find, ive checked the thermostat houseing and no sensor. I then checked the radiator to see if there might be a sensor on it again no go. Then i went to trace the wires back from the fan yet it dissapears into the wiring harness.

No if i understand the term forum correctly its where people come together and discuss a topic such as ummm i dont know say rodeos. Within that discussion people share information back and forth and ask questions in hopes someone knows the answer. The definition of forum does not include someone screaming get the manual and quit asking.

colant temp sensor on your vehicle is located at the back of the engine there is a pipe that runs from one head to the other and the sensor is screwed into it
O by the way it is a real pia to get to

K, like was said before, there is no specific sensor for the fan. The ECM (computer) reads the tempurature of the engine and probably a few other things and the ECM is what turns the fan on and off. Check the fan relay.

One of these sensors is for the gauge in the instrument cluster and the other is the ECT input to the ECM. On the 95.5, there are two wires connected to the ECT sensor, one gray and the other is gray with a black tracer. Your 1996 may be wired the same.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/1486313_2backhighect.jpg

BTW,
I didn't notice Joel doing any screaming, did you? I saw a smiley face and took it as a joke. Sheesh....

Dale