1G Fan not working....

[Black94DSM]

Ok I just got done installing my new JM Fabrication Intake Manifold and now my cooling fan does not turn on.

I checked over all my wire harness connections, everything seems to be hooked up. I checked my fuses, and my relays. All are good. I even replaced the thermo sensor in the bottom of my radiator. That didnt even help it.

I'm lost right now.

Is there anything that im looking over?

I did do a battery relocate at the same time too. Did I fry something on accident ?



I can manually turn the fan on by touching the two wires together at the thermo sensor.

 

[DAmotorsports]

Is the car warmed up to normal operating temp? Those fans if you wired them up to the factory relays are designed to come on at a certain temperature.

 

[Black94DSM]

Of course, I even let it get a little hotter than normal. It got to around 215 or so before I had to shut the car off.

I only have one 16 inch Derale fan, and it is wired up like the factory. Some reason it just decided not to work now. This was after I installed my new intake manifold. There has to be some sort of connector that i'm forgeting.

 

[Rahdigga8188]

Do You have A/C? What happenes when you turn your A/C on.

 

[luv2rallye]

I can manually turn the fan on by touching the two wires together at the thermo sensor.

Doesn't that tend to point to that sensor being bad or it closes at too high a temp?

 

[Black94DSM]

Do You have A/C? What happenes when you turn your A/C on.

No A/C. Thats been deleted for a while now, even before this problem occured.

Doesn't that tend to point to that sensor being bad or it closes at too high a temp?

I replaced the sensor already. Unless the one I just bought is bad too.

 

[blackbyrd]

I hope this helps, this was another post of mine..
The fault is either in the thermo switch, the fan motor, the relay, or wirring harness.
The thermo-switch is located on the bottom tank of your radiator, it'll have two wires comming out of a sensor that screws into the tank.
Check the thermo switch by turning the ignition switch in ON, and removing the connector on the switch, bridge the terminals with a paperclip, it should turn on the fans.
if not..
Check the fan motor by jumping it to the battery, if that doesnt work, connect a jumper wire from terminals 2/4 on the radiator relay terminals, does it work?
Check the radiator fan relay, and connect a jumper wire from terminal 2 to the battery positive terminal, and connect terminal 4 to the negative battery terminal.
..
1 2
3 4
Use an ohmmeter, check for continuity between terminals 1 and 3, there should be continuity.
Remove the battery leads, check for continuity between 1 and 3, there shouldn't be.
Also, check for continuity between terminals 2 and 4, there should be continuity.
If the results are incorrect replace the relay, if they're good its your thermo switch.

To check the thermo-switch, unplug the connector, with the engine cold, use an ohmmeter and check for continuity across the terminals, there should be none. Let the engine get warm and check for continuity, there should be it.

 

[Black94DSM]

Thanks for the detailed post. I will do that in the next day or so.


I can manually turn the fan on by connecting the two wires that go to the sensor. I did a quick check on the relay by just pulling the fan one out and popping in my headlight relay. They looked to be the same. Still didnt correct anything.

 

[blackbyrd]

No problem, let me know how it works out!

 

[Black94DSM]

Well, I tested alot of the items you told me to. Everything came out like you said it should. Im still lost over here.

 

[Jeff822]

Check the coolant temperature sensor, they are like $30.

 

[blackbyrd]

Check the coolant temperature sensor, they are like $30.

The coolant temperature sensor on the thermostat housing, does not control the fans on a 1G. It has it's own temperature sensor located at the bottom of the radiator (thermo-switch).

If you can manually operate the fans by touching the wires together, I would have to say its your thermo-switch, more then likely.
Did you use an ohmmeter and check for continuity on the fan? what were the results?

 

[Black94DSM]

The coolant temperature sensor on the thermostat housing, does not control the fans..
It has it's own temperature sensor located at the bottom of the radiator(thermo-switch).

If you can manualy operate the fans by touching the wires together, I would have to say its your thermo-switch, more then likely.
Did you use an ohmeter and check for continuity on the fan? what were the results?

I just replaced it because thats what I thought it was too. 33 dollars later it still didnt help it. I did check the switch, but now I dont remember what the numbers were.

 

[luv2rallye]

It has it's own temperature sensor located at the bottom of the radiator(thermo-switch).

If you can manualy operate the fans by touching the wires together, I would have to say its your thermo-switch, more then likely.

I agree. The thermo sensor (or switch) directly controls the radiator fan motor relay so if it runs when you touch the wires together, the thermo sensor has to be the problem (it's not closing). Either you got a bum new one or the wrong one [doesn't operate at the correct temperature which is ON @ 85C (185F), OFF @ 78C (172F)].

 

[Jeff822]

This is what was happening to my friend, leave the car on and tap against the relay lightly and push it over a tad it might just be a loose connection. When he did that to his his fan would turn on then when he took his finger off of it the fan would shut back off.

 

[Black94DSM]

Ok , well thats the least of my worries now. If you look at my threads I started I posted that my car has a rod knock now. So I now could care less about this issue.

But thanks for all that helped me. Im sure I will be addressing this issue again when the motor is back in and running.

 

[blackbyrd]

Ah, I'm sorry to hear about your luck man.
I rode my rod knock out for about 30k miles til it spun.
I'm in the middle of the engine swap now, new rebuilt longblock.
Good luck!