what to do for further testing of fan in mk2 jetta gl 1989

[dbbarney]

I jumped the plug that goes to the temp sensor in the radiator. One side runs, the other side does not. Testing suggestions at this point? The fan does not initially come on w/o ac on. But it stays on when i turn ac off , cools the car and then turns off. What to do for further testing of fan in mk2 jetta gl 1989?

[Glegor]

I jumped the plug that goes to the temp sensor in the radiator. One side runs, the other side does not. Testing suggestions at this point? The fan does not initially come on w/o ac on. But it stays on when i turn ac off , cools the car and then turns off. What to do for further testing of fan in mk2 jetta gl 1989?

figure out where the high speed relay is (i told you the location in the other thread) and go from there..

if the high speed relay is bad, it doesnt matter what you do, trying to fix it.. the relay needs to be replaced if its bad. also, check the fuseable link for the fan.

pull the high speed relay, check for power there. if there is power clear up to the relay, then jump the fan at the relay socket. if the relay is bad, then the fan should light up when you jump the terminals. be VERY CAREFUL tho, because whatever you use to jump the fan, will get VERY HOT when you use it to jump the high speed side of the fan. i used a paper clip once, and it got soo hot, soo quick, that it burned a horse shoe shaped ditch into my thumb and index finger..

its going to be basically REQUIRED that you have atleast a DVOM, and a test light, at a bare minimum..

[dbbarney]

fuse box- which relay am i looking at? I'm guessing #31. I included a photo.

Also, when I turn on the ac in the car the fan goes to high speed immediately. When I turn off the car the fan still runs at high speed for a bit. I disconnected the temp switch at the radiator and the fan continues to run high speed for a bit even tho the temp gauge is not even halfway. I'm not sure where a fusible link would be. I replaced all the connections up front because they were totally corroded from battery acid.
I have a manual but dont see anything about the location of the relays. What behavior will I notice when I simply remove the relay? I really appreciate the help.

http://www.flickr.com/photos/5468088...in/photostream

[Glegor]

fuse box- which relay am i looking at? I'm guessing #31. I included a photo.

Also, when I turn on the ac in the car the fan goes to high speed immediately. When I turn off the car the fan still runs at high speed for a bit. I disconnected the temp switch at the radiator and the fan continues to run high speed for a bit even tho the temp gauge is not even halfway. I'm not sure where a fusible link would be. I replaced all the connections up front because they were totally corroded from battery acid.
I have a manual but dont see anything about the location of the relays. What behavior will I notice when I simply remove the relay? I really appreciate the help.

http://www.flickr.com/photos/5468088...in/photostream

should be relay 31..

[dbbarney]

Glegor, or anyone, does the white sensor mounted in the flange on the end of the engine block have anything to do with the fan problem? I currently have no lead going to this sensor but I have always had the sensor mounted in that flange since I've had the car.

Water Temp. Sensor

A/C Cut-Off
With Digifant
(119c 2 Pin, Grey/White) Mounted in water flange at cylinder head.

[Glegor]

Glegor, or anyone, does the white sensor mounted in the flange on the end of the engine block have anything to do with the fan problem? I currently have no lead going to this sensor but I have always had the sensor mounted in that flange since I've had the car.

Water Temp. Sensor

A/C Cut-Off
With Digifant
(119c 2 Pin, Grey/White) Mounted in water flange at cylinder head.

there should only be 2 sensors mounted in the front water neck. one for the gauge, and one for the ECU..

the switch that controls the fan is mounted on the lower drivers side of the rad..

fan sounds as tho its functioning fine with a/c, just not on HIGH speed..

and the HIGH speed side of the fan is controlled by its own relay. if that relay, or wiring to the relay is bad, the fan wont work. have you verified power to the relay? have you tried using a jumper wire (pretty thick wire) in place of the relay?

[dbbarney]

I have the black sensor and the blue sensor in the flange nearest the radiator. Then there is the OTHER flange that connects to the heater core hose with a sensor that is white/gray plastic in color. Descriptions of this sensor mention it is called the 'AC cutoff' sensor. It is mounted in the black coolant flange on the END of the block, facing the left side of the engine bay. Mine has been there since I got the car but there is no plug present. It is described as Water Temp. Sensor, A/C Cut-Off, With Digifant (119c 2 Pin, Grey/White) Mounted in water flange at cylinder head.

Regarding the fan, it currently only runs on HIGH and only when the AC is on. With the ac off it just runs sporadically off and on sometimes for a few seconds, sometimes 15 min after the car is off even with a normal temp engine. Thank you.

Regarding the fan relay on top of the fuse box, how do i know which terminal is power and which are ground? Thanks again