what im looking for is someone who has a stock wiring diagram for an 87 formula firebird with dual fans. im having problems with them, wierd problems, and i can't figure em out, and i think i wiring diagram of how the fans are wired from the factory will help me chase down the problem. thanks

 

its basically this without the manual fan switches.

 

happen to have / be able to take a picture of the A/C high pressure switch?

my A/C compressor is shot.. would that cause the secondary fan to stay on constantly?

 

if the a/c switch has closed shut and grounding the relay yes that would make the fan turn on.

 

Technically speaking, that diagram (which has been used a lot on TGO) is incorrect in one small way. The second non-ECM controlled fan is also wired to the ECM. However, it is not wired to the ECM for control. It is wired to the ECM simply for letting the ECM know. The ECM looks for the ground (via the A/C pressure switch, or the Temp Switch in the head). The service manual wiring schematic is HERE. Why am I posting this? Because it gives those who have removed their A/C another option. I've attached a pic below that represents the way the initial image should look. I'll post another one later with the mod I am referring to for Non-AC cars.

Tim

 

Remove the A/C pressure switch.
Remove the Head switch (or leave it in as a plug and just unhook it).

Simply jumper the pins at the ECM (red). Now when the ECM commands the primary fan to come on BOTH fans will come on. Or - you can flip the switch and both fans will come on.

Tim

 

The "temp switch" is this the temp sender? Or is this something else?

If it's something else, could you physically take a picture of where it is?

And take a picture of where the A/C pressure switch is?


Once i find out where both of these are, is there a really simple way to see if either of them is broken / wrong?

 

my relays accualy have a wire coming out of "E" and not a wire at "D", perhaps the relays are different? im sure the rest is probobly the same, cause when i pysiclaly close the relay the fan runs with the car off even, but now not at all, so i probobly burned somthin up i guess. just thought i might throw that in there in case somthing is wrong.

 

Traxion, did you get that diagram out of a chilton or haynes service manual? i think i have chilton, if thats it where did you find that? was it in the supplemental section?

 

well im the one who made the original. and if i remember correctly i made those diagrams based off what was on my car. now that i look in my factory manual thiings look a little different. (such as a wire at c instead of d) if i can get my scanner working ill post the factory manual diagram.

 

 

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Those last 2 pics, what manual are they from? Also, how is the A/C pressure switch hooked up on a single fan system, and where would it be on a L03? thanks

Eric