hey all.. i know there are more than a few of these posts laying around but i had some very specific questions:

I did a search and read up on the cooling fan threads and here is what i did:

I checked the fuse box under the hood and the fan fuse was good. I took a look at the relays, but didnt really know how to test them. None of my fans are coming on .. which would mean that both of my relays are bad, or the ECT sensor is bad.

How often does the ECT go out?
How do you test relays?
It was dark and i plan on jumping A,B on the diag port to see if they turn on.
I dont have a SES light so i am assuming the ECT is okay..

Please help

 

An easy check to see if the fans them selves are good is to turn the AC on. Fans are supposed to run constant with AC going. To do a check on the relays use a volt meter to check the ohms when it is in a closed condition. If it bad you get no reading across it meaning no contact, or a high ohm value showing alot of resistance or bad contact. A good Ohm value should be close to zero.
If you prove the fans working and fuses are good, it is most likely the relay.

 

will the a/c fan test work if my system is low on freon? Right now when i turn on the AC the compressor clutch engages.. and then stops.

Okay this is where the manual lost me too..

When you say test the relay when it in closed condition what does this mean?

 

first, is there pwoer to the fan relays? key off, there sould be power on one wire each

 

I will have to test that when i get home.

 

Providing car year and model info would be helpful to get correct diagnostic info. The relays are not powered the same in all years.

You can easily test relays by swapping them for the foglight relay and operating it.

 

It is a 93 Z28 M6

I have been messing around with other nagging issues.. so i havent had time to test as recommeded by the previous post.

I tried to look at the model number on the relays.. and i couldnt tell if they were the same.. should i be concerned? My relays were really dirty and hard to read. Will it be okay to just swap them?

While the car was running it got really hot.. like near into the red and nothing.. Of course i was also low on coolant.. but i didnt hear the fans kick in.

 

The fan relays and the fog light relay are the same.

If the engine coolant temp sensor is not immersed in coolant all the time, it might give an erroneous reading to the computer. If you know you are low on coolant, why not fill it up?

Short A and B together on your DLC and turn the key ON (don't start). Your fans should come on.

 

Hey shoebox.


I am working on the cooling system. I have a few leaking hoses and had started to car so that the system would suck the coolant from the res back into the radiator. I will fill up the system and then test.

 

The only time the system pulls coolant from the reservoir is during engine cool down (not running).

 

So your fans are not turning on when running only? Or they do not turn on period, like when you jump the two ALDL slots with a paper clip?

If they don't turn on when the engine is running only, then I would check the coolant temp sensor in the water pump. Turns out my sensor had bad wires coming out of it, and then they got screwed up even more so I had to do a manual fan switch.

 

I just got all the hoses on and didnt have the time to do the jump connectors. I filled and bled the cooling system and i will test tonight.

How do you install a manual fan switch?

 

http://shbox.com/1/fan_switch_wires.jpg

http://shbox.com/1/fan_sw_diagram1.jpg

What I did is just splice the blue wire (high speed) and left the low speed one alone. The high speed one cools it off enough to keep it at safe temps. Then I routed the wires through the firewall, right below the PCM (had to remove the PCM to get to it) and poked a small hole through the bushing/rubber thing. Then brought the wires down below the glove compartment and to the center console. If you need anymore help, there is shoebox's site and I could try and answer some questions.

 

shib...

thanks. I will test the darn thing tonight to see if the fans turn on. I'll take it out for a spin. I ran it last night, but it was too cold outside (in Cali!) for the temps to creep up.

P.S..

Anyone notice more of a 'whoosh' sound after installing a tpi airfoil?

 

Nope. I didn't notice a darn thing of anything when I installed mine. wait...yeah I did...my wallet was out 15 bucks