Problem - probably electrical

[avokado 10]

Hello there,

 

I would really apreciate some help, getting my baby back to how it should be.

 

Let me sumarize the situation. It's a us spec vr6, with 2.9 ABV swap. I got the motor from a pretty nice runnig car. When the mechanic, that help me do the swap finished his job, the car took quite a few cranks, before it started (to this day, the problem remains), hot or cold. Took me about 2 years to get the will power back to mess with the car, and started on working on the quirks.

 

I noticed that the fans aren't comming on, ever. So i first tried to bridge the cooling sensor to check for defect, but fans won't start. The fan control module seems to be ok, fuses to. Then i dug a little deeper and noticed that one of the sensors on the thermostat housing isn't pluged in. It was the black sensor, which obviously isn't ther right one (my car has AC). I now got the brown 4 pin sensor, but planing on changing the thermostat, while I am at it. Also, i have noticed a few connectors in the engine bay (by the battery) that aren't plug in to anything.

 

I have no idea on how to start checking, what to do first, so if you could give me some pointers, that would be splendid:cool:

 

Should i post a few pictures of the situation (connectors, their position, sensors, etc...)?

 

Thank you for all the help,

Luka

[Jim Bowen 1]

I mistakenly cut my Brown/black sensor out, thinking it was only needed for air con, fitted a blank to the thermostat housing. It had no effect on the fans so i'd discount that. Can you connect 12v power straight to the fan motor to check that is working?

[avokado 10]

Ok, so I definitely need to sort it out, but won't fix the current issue:)

 

Fan works with 12V power.

[swiftkid 1]

Black sensor is 3rd fan speed and if you have A/C it should be a 4 pin with that aswell. Have you bridged the yellow temp sensor or the radiator temp sensor to test the fans? I can't remember which it is but you can get the black or blue temp sensor plug mixed up with something, think its cam position sensor maybe as they have similar length wires and same plugs.

[avokado 10]

Yup, i have bridged the coolant temp sensor, nothing happens.

[fla 9]

as swiftkid says have you bridged the sensor in the rad itself? If you do this the fan will come on a low speed immediately, even with the engine off.

[avokado 10]

fla, i have bridged the coolant temperature sensor in the radiator, nothing happens. Direct 12v starts fan... The fuse on the FCM is ok, got 12v on the FCM.

 

What is next?

[fla 9]

Change the rad sensor. I think it's only about a tenner.

[avokado 10]

Why change it if it's working? For now, it has been ruled out as faulty...

 

Anyways, a messed around with a multimeter yesterday, and i have ground bot no 12V anywhere on the wiring. Could i have bad FCM? Should be good, but as there is no way to test it outside the car, is it best to just buy a new one and se what happens?

Edited July 21, 2017 by avokado

[avokado 10]

Update:

 

Checked the wiring from a to b, everything looks fine. But i still can get power, so i blame it on the FCM.

 

Is there any way of testing the FCM, before i spend 200 on a new one? (I know there are chinese ones for 20, but i am not willing to risk it...)

 

Cheers

[avokado 10]

Can somebody please verify that the red wire from the thermo sensor goes directly to the fusebox yellow connecto A1/pin5?

 

Is there some other possible option to get 12V on the thermoswitch?

 

Thanks!

[avokado 10]

Found the problem - somebody hackeled the relay for the lights, and used the fan power supply...