im looking for the green and blue wires on the harness plug by the pcm. there are like 4 green wires and 2 blues at least. i think the wires i want are right next to eachother on the side of the harness plug that faces the driver side or away from the pcm. can anyone tell me if these are the right ones? does anyone have a picture??? thanks to all who reply!!

 

"H" and "J" in the connector in the top of this pic.

What year is your car?

 

thanks shoebox, i have a 94. ok let me run this by you:
im connecting the two fans to a 2 prong switch with an led light. im putting the blue wire, green wire, and 12v wire on one prong and the ground on the other. is this ok to do? i dont want to screw up my pcm or anything, and the light is meant for 12volts. thanks!

 

Do as ACA said and get a double pole, double throw (DPDT) switch that on the bottom looks like the wiring diagram. Wire it just like it shows. I don't recommend using a switch that has a light in it. You don't want to put any voltage at all toward the blue or green wire.

If you wire it like the diagram, even when you are not using the switch, the LEDs will light when the pcm turns your fans on. That is kinda neat to be able to know when they are on. I am not using a fan switch on my car, but have the LEDs monitoring my fans.

Oh BTW, on a 1994, the 10 way connector with the blue and green wires is down by the base of the hood support, closer to the pcm. That is why I asked what year your car was.

 

Also a 94 if 'early production' doesn't HAVE hi and low speed fans[3 fan relays]... late production 94 does however...
it has dual primary and secondary single speed fans..[2 fan relays]

 

Charlie is naturally correct.

With either fan system, the colors that control the relays are the same and your fan switch will operate the fans in the same manner as when the pcm turns them on (either primary and secondary or low and high speed).

 

my car was made in march of 94 so it probably just has primary and 2ndary fans. im going to put the blue and green on one prong and the ground on the other. i guess i will save the light for something in the future. it sux cause i already had it mounted with the switch on the cig lighter plate

 

Ok, so if you put the blue and green together so that when you throw the switch that ground is applied to both of them, that will turn both fans on high (or both fans on, in case of the early system).

 

ok one last thing about the light. what if i do this:
attatch the ground circut of the light, and the green and blue wires to one pole, the actual grounded wire on the 2nd pole. and have the 12volt wire go directly to the 12volt circut on the light. will this be ok? will the 12 volt not connect to the blue and green through the ground wire?? i promiss this is my last question on this topic. thanks!

 

Sounds like it might work, but a correct answer would depend on the switch you are using. Can you post a pic of it or anywhere to see it online?

 

sorry i dont have a way of posting a pic of it. its a off/on paddle switch with 2 poles on the back of it. i think its going to work.

 

Appears by your description to be a reg on off switch[SPST]
How does the light get it's power then?[if not off a 'pole'?]
Is there a seperate pole for the 'indicator lamp' in it?
If not, I'd not try to put 12V+ to it.. [some of those use the 'hot' off the line that you are switching... which in this case is GROUND only, so it won't light it.. also this type usually 'ground' the indicator lamp from the panel that it's mounted in...]
Correct me if I am wrong, [and there are more 'poles' on the switch than the 2 you mentioned?...]
If you really need the indicator, get another switch that has seperate wiring for the lamp..

 

i bought the light seperatly. i hooked it all up and its working fine.
i have the 12 volt going directly to the light. and the ground wire is on the same poles as the blue and green so when i switch it , it grounds the relays and connects the ground to the light.

 

OK I see now thanks for that info..
Glad it works.. I would think a DPST switch might have been better, as then you could have isolated the indicator light from the fan grounding circuit.. [but if it works OK, it should be OK..]
A question comes to mind:
If you have early production[2 under hood fan relays rather than 3]dual fan single speed primary/secondary fans, does grounding both wires together cause BOTH fans to come on all the time you turn them on?
And do BOTH come on each time the PCM calls for fan operation?
[I suspect they do.. since you have in effect connected BOTH PCM grounds together?]
Problem with that would be that the PCM calls for each fan seperately [according to demand...]
If they don't it's all OK.. I am just thinking having both grounds on the same switch pole would 'connect' the 2, making both fans run every time one or the other is 'called for'?
Charlie

 

They are called for separately, Charlie. So connecting the grounds together on the switch like that, would do just what you said. You would always get both fans on when only 1 was called for.

That is why the diagram and switch were specified like they were and why they should be followed to avoid modifying the normal fan operation. That would definitely cause trouble codes on an OBD-II car. OBD-I does not seem to care as much.