I need some help. I have an aftermarket controller to run both fans but they're pushing instead of pulling. They're otherwise operating as advertised.

I reversed power to the fan terminals expecting them to spin the opposite direction but that didn't do anything.

As it is, when idling and cruising around under 35 the car gets stupid hot up into the red. If I stop at a light, it cools down and on the highway it seems OK but the fans are definitely pushing and not pulling.

A friend says his 91z also pushes instead of pulling. Any truth to this?

I can't drive it like this.

Does anyone have any ideas?

 

Sounds like something isn't right for sure.
Fans need to pull air from the front of the car through the rad into the engine compartment.
If the fans in your friends car are all stock, he is lying or just doesn't know.

 

My issue is that the original harness caused the fans to spin right, causing a pushing action. I had two pigtails sent that were supposed to flip the power on the fan terminals. Plugged into the harness, the fans still spin to the right.

Separately from the harness, I ran manual power from the positive and negative battery terminals through the pigtail I was sent. Its perfect, the fans spin left creating a pulling action.
Watching up the pigtail to the harness wire, it does indeed switch which power terminal on the fan motor gets power. On the surface, this should have fixed it, except it didn't.

 

Well, I found power on the negative fan terminal and power on the positive fan lead. When I ground my temp switch, the power on the "power" lead, the orange wire, drops to zero but I still have 12 volts on what should be the ground wire.

Unfortunately, it looks like manufacturer defect here. Thankfully, they worked with me tonight for an hour troubleshooting it. and that's where we got.

 

Ozz1967 ,
Dammmm.......
Please keep us up to date.

 

Will do!

I was so focused on "It works" that I didn't notice the fans were spinning the wrong way. Cools down just fine when sitting still, but when moving the fans fight the natural airflow and the car shoots up into the red.

Formula1LE's been working with me and he's actually going to build another harness just like mine to see if he can duplicate the effect with spare fans at his place. Everything is hooked up and we spent almost 2 hours checkign wires last night to be sure. What we don't understand is why there is voltage on the ground wire.

There's more to come...

 

The factory fans shut off over 40mph and that's 1 reason the airdams are so important.

 

Yup!

My airdam is intact and functional.

 

Why not just pull the ground wire out of the harness and ground it?

 

Because that would be so simple....it never occured to me?


The guy that created the harness is making a duplicate to see if he can recreate my issue.

The main problems are this:

1. On what should be the main power wire, the 12V drops out when the temp switch is grounded. It shouldn't disappear.

2. On the ground wire coming out of the relay bank, we have 12V. There shouldn't be 12v, or it should be dropping to zero (As the power wire does currently), for the fans to operate.