ZackZ420

Hello fellow third geners. I don't know if this should b here or electronics. I was wondering if anybody ever spliced the secondary fan into the primary so both turn on when first fan is supposed too. And if so was it relatively eady. And does check engine light come on because the cooling fan switch is connected to anything anymore.

Tuned Performance

iTrader: (92)

If you have the ecm control the grounds of your relays you should wire it like this.
You will also need to get your computer chip reprogrammed.
There will not be any ses light when you rewire it. It would be better to leave well enough alone and install a sw555 switch for the secondary fan. It kicks on at 210 and off at 205f.

Galaxie500XL

iTrader: (1)

On my '88, I simply replaced the thermal switch (on the passenger side head) with a unit that comes on at 190 degrees. Cost was less than $15.00, and it allowed the secondary fan to come on earlier.

mmadden55

^ This

ZackZ420

So your saying the four seasons fan switch correct?

Go Blue

I have that aftermarket switch turning my main fan on at 160 (or at least I believe that's what the original owner said). Now that I took out the AC, i'm not sure if the 2nd fan will ever kick on though since I won't be setting the ac to on. lol. I'm guessing that the secondary fan is just going to sit idle unless I jump that relay, correct??

Tuned Performance

iTrader: (92)

The fan will come on when the sender is grounded or when the ac is commanded on. It should still kick on with the head switch as long as the wiring is still all there from the switch to the relay.

Tuned Performance

iTrader: (92)

Incase you wanted to see a schematic. Not for your ecm but yours is wired the same way. Look at the bottom of the schematic at the a/c pressure switch and head switch.

Go Blue

Could I just run a jumper from the BLK/RED wire from the primary cooling fan to the BLK/PNK wire of the secondary cooling fan? That way they both come on at the same time? I don't want them running all the time, but i'd be happy if they both came on at the same time. I would also, remove the secondary cooling fan relay so that a secondary power source doesn't turn on and send too much power to them.

Tuned Performance

iTrader: (92)

I don’t know if the ecm can handle controlling both relays grounds. You would have to connect the gray wire to dark green/white stripe wire. The head switch can control both fans grounds but it seems like people complain of it failing fairly often.
You could run a toggle switch to ground and control the relay if you notice it getting to hot.
A grand national head switch sw555 comes on earlier. Stock is 226f the gn is 210 on 205 off.

Tuned Performance

iTrader: (92)

I guess a 3rd relay could be added to the mix. Have the ecm control it’s primary side and have the secondary be a ground instead of a hot running through it.

Go Blue

I know I have an aftermarket fan switch in the head but i'm not sure if it's a 180 or 160 temp that causes them to come on. It was installed by the previous owner. I would rather do something more reliable than having to fix or replace something on a regular basis. Almost sounds like my best move would be to get 1 large fan and leave it at that. If that's not enough, then get a pusher as well and figure out that wiring.

Tuned Performance

iTrader: (92)

Looks like your ecm can control two fans. You would need to pick maybe rbob brain to find out the secondary fan control output pin. I have looked and can’t find the pinout for your 1227165 for the secondary fan control but in the programming it shows two fans it can control.

Go Blue

OK. Thanks for the help! As usual you've been a huge help and it's greatly appreciated!

Tuned Performance

iTrader: (92)

I might be interpreting this wrong. But it shows the secondary fan one and off slightly different . I thought I read somewhere where a secondary fan could be controlled bye the ecm.

Go Blue

I guess it could be possible. I haven't had the car running long enough to have the fans come on as i'm still in the process of rebuilding it and making it street legal and safe again. I do have a JET ECM chip in there now, so it may already have that under control and i'm just unaware of it turning them both on or not. The car had AC and I removed it as I don't like AC (not to lose some weight).

mmadden55

You can but you will be pulling double the amp load through the primary fan circuit and could blow the relay and or fuse. I would set up a separate relay circuit for the second fan and a manual switch or a second thermal switch to kick it on. circuit is simple.

Tuned Performance

iTrader: (92)

Bummer looks like there is just one fan control at c1 of the ecm.

Go Blue

Thanks for checking Tuned Performance. I'll figure something out when the time comes to get it on the road and watch the temps.