does anyone have a picture of how the original electric fan wiring went on an 84 trans am 305? when we bought the car years ago the wires were cut and put on a switch to run all the time. we are wanting to hook the wires back the way it was suppose to be so it will come on and off when needed. we found two wires close to the back driver side but it has no power so we don't think that's it. the car gets a little hotter when we shut it off and will take a little while to start do to this. i think the original setup would allow the fan to continue to run after the engine was shut off to help cool it down. anyone have pictures of how the fan wires run and where to?

Was it an LG4 or an L69?

i believe the L69. i know it was the top of the line H.O.
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it is L69, I just checked.

There should be a green wire from the fan relay to the fan switch in a cylinder head (probably passenger's side).

The original setup does not run the fan past the time the key is shut off. When the key goes off, the fan does too.

The fan switch is in the passenger side head.

[quote=Apeiron;3823246]The fan switch is in the passenger side head.
Doh!...that was what I was thinking, just wasn't what I typed...

thank you. I'll look for that in the morning. we're just tired of always having to turn a switch on. we usually turn it on as soon as we start the car so we don't forget and it runs all the time. I'd rather it not run if it doesn't need too. thanks

is this it? this is the only wire I find that doesn't go to anything. I looked and there are no green wires or blue just sitting around that aren't all ready running to something. no cut wires anywhere either, other than the two black ones we found on the driver side but they don't get power at all.I traced the wire from the switch that is in the block and it runs behind the manifold over to the driver side and into a plug that is all ready hooked up. ???

Nope. That one is for a hood light, if your car is equipped for it.

The fan switch is on the passenger side cylinder head. It is roughly between cylinders #6 and #8, although since your wiring has been modified, the switch may be there, but the wiring may not.

The fan relay is along the firewall, on the drivers side of the car, outboard from the brake booster. The green wire that comes off it needs to go to the fan switch. That wire will activate the fan anytime it is connected to ground, and the key is on.

thanks, that helps a lot. I found the switch in the head. I'll look again tomorrow on the driver side for the other part. nice to know what that plug goes to now.

If you can find the wire from your manual fan switch, you have found the wire that needs to be connected to the switch in the head.
You can, in fact, leave the switch connected to it. If you connect that wire to the cylinder head switch, and your manual switch, it can be activated by either of them.

thanks guys. i think I'll have to leave it as is. I have searched everywhere and followed the green wires etc. and everything is all ready hooked up to something else. no green wire just hanging around. I see the switch on the head but it has a blue wire. even followed that one and no luck. the driver side has a green wire hooked up in the head but that's it. no where to hood it back up to. our fan has two black wires that had been run along the driver fender to the overhead console originally and now is a switch under the dash. thanks though.

You're not running the fan current through that switch, are you?

Sorry, I'm not much on the electrical stuff. my husband had put a switch with a 35 fuse built into it, I think 35, and when we turn on the car we just push the switch to the on position and it runs. that's kind of how the previous owner had it except they had it just wires in the overhead console directly to the overhead light and a switch with no fuse. it would get very hot and burn the switch out also had to replace fan motor. that's all I know. I mainly do a lot of work on replacing parts etc. but have never been one for the electrical stuff.

You really don't want to run all that current through the switch like that. You need to use a relay.

how would I go about doing that? sorry I seem to not know much about this.

is this the relay on the driver side by the firewall? I found a picture of one on advanced auto parts and it looks the same. If so how do I hooked it up to the fan? thanks

Yes, the fan relay should be one of those in that picture.

FYI, that connector is the diagnostic terminal to connect a dwell meter for the mixture solenoid testing.

Larry

A relay is simple to hook up.
a 4 pin relay has the needs hooked up as below:
pin 30 - plug this into the + side of the fan
pin 87 - plug into + side of battery (fused)
pin 86 - ground
pin 85 - plug into 1 side of switch

Switch pin 1 goes to pin 85 on relay
pin 2 goes to + side of battery (fused)

On the switch pin 2 can either be constant power (this means that the fan can be turned on at any time) or it can be put on an ignition only power (this means that the ignition has to be on to get power) I always use a 30/40 amp relay

thanks, that helps out a lot for understanding how to put one in.

is this the fan switch? it's on the driver side head and has a green wire the one on the passenger side is in the block. I saw a picture of the knock sensor at advance auto parts and the passenger side looks like it just mine was painted black when the engine was done . these are the only sensors on the side of the heads or block.

The first picture is the gauge sender, the second one is the knock sensor.

the fan switch should be above the knock sensor in the exact same spot as the temp guage sender on the driver's side head, just turned around to fit on the other side (the heads are interchangeable).

I guess it's been taken out then. the only thing I saw above it was a plug in the head. there are no other parts going into the head or block other than plugs. thanks

It's extremely unlikely it was taken out and replaced with a plug. That would have involved 'work'. The LG4, without electric fan, would have a plug in the head. Vin H in 8th place?

we have ( or had ) the L69 engine code. in the exact spot is a hex shaped bolt that can have a tool inserted in it. it is in the exact location of the one on the driver side just by the 6 and 8 plug. I looked again and there is nothing else that goes into the engine block or heads. we got a new block but kept the heads. i know the previous owner said a lot of work had been done to the engine of the car to make it more of a hot rod when we got it. the fan wires were cut and run directly into the upper console to run constantly. they believed the engine had been bored out before. there is defiantly nothing in that spot other than that plug.

Pull the plug. That's where the temp switch should go.

thanks, I'm glad I finally got that. Now i just have to buy one. I believe the relay is still attached on the firewall. I'll just have to have my husband figure out how the wires go to the fan. wires had been cut, chopped and rerouted all over the car when we first got it. not sure if they were put back in the correct location when we had the engine redone. thanks

Constant hot power wire to the relay should come off the always hot starter post. If the original switched 12volt control voltage wire is gone, one can be pulled from one of the other relays adjacent. The control ground lead can go back through the wiring harness over the pass side valve cover following the knock sensor wire to the switch. Power lead to fan can tuck into the harness that runs along the driver's side frame rail although I've seen other models where it wrapped around on the other side.

You want to pull at least #10 wires for your power and fan ground (which can terminate at the nearest ground point on the frame). The amp draw will exceed 20 amps on start up so a standard automotive type 20 amp fuse won't work. The factory used a fusible link which is basically a cheap slow blow.

Thanks for the information. This really helps a lot.