Can't get electric fan to work

[ncbrock]

So I followed this diagram, and my fan wont switch on unless I jump the wires on the new relay I wired or the high speed relay (pins 85&86) on the fuse box. I have a new 82C 3 prong thermoswitch. I've read all the write ups and I can't figure out what is wrong, it seems like the thermoswitch isn't sending the right signal when it reaches a certain temp.

[agent]

Look here yet?

http://www.r3vlimited.com/board/showthread.php?t=210783

[ncbrock]

Yep checked that out, thats basically how mine is wired. I guess I could get new high and low speed relays.

[spdracrm3]

the diagram you posted in the first post is wrong for the way the thermo switch (fan switch ) works on your car ,your diagram has the thermo switch switching ground at set temps where if you look at the diagram in the link you'll see that the thermo switch (fan switch ) is switching power from fuse 19 on Grn/Blk wire to the relays so you have power to both control sides pins 85,86 of relay and they wont operate .they need one grounded and one 12v power to operate...

you need to ground the pins 85 (chassis gound) and route power from thermo switch Blk/brn (low) and Blk (high) to pins 86 of your relays and then they will work

so in a way your correct when you said "it seems like the thermoswitch isn't sending the right signal when it reaches a certain temp." because its power, NOT ground

[AndrewBird]

^^^Exactly what he said. Ground 86 and it should work.

[ncbrock]

Perfect, thanks guys I'll try it out tomorrow.

[ncbrock]

I just did as spdracrm3 suggested and changed pin 85 to ground and also changed pin 86 to blk/brn on thermo switch, and still no fan at desired temp. All fuses are in tact and replaced some relays.

[spdracrm3]

next ? is how do you know its at the temp the fans turn on at? they dont turn on till about 3/4 on the gauge if i remember and if you still have a mechanical fan it may never reach the switching temp unless its really hot outside or A/C is on

or you can test by jumpering the two relay feed pins @ the thermo switch to the fuse 19 feed pin and see if the fans come on at both speeds Grn/blk to Blk/brn for high fan Grn/Blk to blk for low fan