4montecarlo

on my 96, the fans will not come on
the temp has gotten nearly to the red w/o either fan coming on. when i turn on the ac, one fan works. i have ohmn tested the temp sensor in water pump, and readings match what they should be from shoeboxes website(thanks its very helpful)
each rely works when i swap it out with fog light relay.
i get 12v power to the d1 on primary relay, but not the other 2
and i get 12v with key on to the d5 on each relay.
but why dont i get 12v power to the d1 on each relay?
thanks
matt

shoebox

D1 is only on the one relay. The other sockets are J and F. Reading the schematic, you not supposed to get 12v on J1 or F1.

If you unplug C100 and ground J back toward the fans, the low speed fans should come on. If you ground both J and H, high speed fans should run. If it does, everything from C100 toward the fans is ok.

4montecarlo

I have looked at you diagram, and i see c100, but where is that on the car?
I drove it around again last night, the fan will only work when i turn the ac on, no matter how warm the car gets.
So, i need to find that c100 and i will try that.
thanks
matt

shoebox

C100

4montecarlo

great, i will look for that this weekend
thanks
matt.

4montecarlo

found the c100, tested the fan and everything forward of that works.
so now the problem is the electrial lines from the temp sensor to the computer or computer to c100 electrical lines or the computer is just not working
correct? and to do that i need to check the temp sensor input at the computer and fan output?
thanks
matt

shoebox

My Tech Page has info on testing. A scanner would be of use, as well.

http://shbox.com/1/4th_gen_tech2.html#ect

http://shbox.com/1/4th_gen_tech2.html#cooling

4montecarlo

borrowed a snap on scanner this weekend
that thing was pretty neat,
but the gauge was reading about 20-30 degress higher than the pcm
so now one sensor is wrong or i have a flow problem from the heads
thanks
matt

4montecarlo

still fighting with this problem
i replaced the temp sensor to the computer and had autozone warranty the temp sensor to the head as it was reading to high.
i also got a cheap temp gun, shows the heads to be in the 230 range while the water pump sensor is only reading low 200
i assume i have a blockage? where does coolant flow from into the heads? i think it exits the heads along that pipe on the passenger side of intake?
thanks
matt

93formula

perhaps the reverse flow heads have something to do with it, you got one sensor thats on the waterpump and gets its reading pretty much after the radiator and the other sensor is in the driver side cylinder head, its possible that the temp heats up to that point. the heads get the coolant first before the rest of the engine block. if your fans turn on when there supposed to i would not worry about it. but if your concerned you can do a simple flush, hope that helps. what about your thermostat?