No Rad Fan After CE2 Swap

[theman53]

The fan shouldn't run wired like that unless it is hot enough to run. I think some wires are crossed or something as this is a weird deal. I honestly think better you than me to take on this project. Hopefully you will work it out soon and you will be happy with it.

[TylerDurden]

IR thermometer is your friend... I'd use it to know if the temp gauges are lying.

You can also test the sender by comparing to known good. Here's a chart for a sender I tested.


You can test the gauges by putting resistance in the sender wire equal to resistance at a given temp (e.g. 500ohms should read low, 100ohms should read high.)


WRT the radiator fan, the AC relay and fan thermo switch operate in parallel... both should have the ability to turn the fan on, but neither should be able to turn the fan off (if the other has it on).

[jhax]

IR thermometer is your friend... I'd use it to know if the temp gauges are lying.

You can test the gauges by putting resistance in the sender wire equal to resistance at a given temp (e.g. 500ohms should read low, 100ohms should read high.)


WRT the radiator fan, the AC relay and fan thermo switch operate in parallel... both should have the ability to turn the fan on, but neither should be able to turn the fan off (if the other has it on).

Tyler, thanks for the input, although I am pretty positive my temperature gauge works fine. The car's cooling fan will not come on at all when the AC/Fresh Air Fan is off.  Temp just rises and rises until the light flashes. No after run or high speed. I don't see how the wiring could be mixed up but Ill look again anyway. I literally pulled it from the car in the yard and put it in my car. It should theroetically plug and play with N2 (coolant fan power) and A1/6 (AC fan power).

[theman53]

If it is over heating, do you have all the air purged out? I would think so with the many cycles you have had but just checking.

[jhax]

I believe so, i let it sit at idle yesterday and squeezed upper and lower hoses several times no bubbling, just coolant out of the small return hose. Ill loosen the cap and drive to walmart down the street and back and see what happens. Theman, I switched the wire going to the starter from the RED/WHITE wire going to N2 and the AC system (causing the fan to be on all the time) to the RED wire going to the after run and thermo switch an let it idle and no fans at all, even with the fan turned on. But on a brighter note, I got my amplifier all wired up.

[ropadopa]

I swear those fan circuit are possessed,  have a 92 eco diesel that wont turn on either , works with ac on, even runs 10-15  seconds after car is off, wontr run with ac off and let it get warm , changed temperature switch in radiator , tried bypassing it, traced allot of wires around , seems there is a signal from fuse and relay panel that isn't doing its job, finding accurate wiring for my car has been poor,  Not to mention i think i have a 3 speed fan..ahhhhhhhhhh

Its been like that for almost a year, but i run ac all teh time here in florida so it works great, I remember getting into this a while back and my conclusion is that there is a relay not turning it on for me and i couldn't find the right one nor a matching diagram of my fuse/relay box and gave up after guessing  at a few with no luck-

good luck with yours , 

[jhax]

Can a relay take the power/ground from another relay?
 
I ask because This 1990 Jetta that I took the AC harness came with a relay that clips onto the main box and I believe it is labeled as the Radiator Cooling Fan After-Run Control Unit (A/7) On A2resource, there is only 1...count them ONE, UNO, ISH wire going into this pin.

This jetta has 2 wires going into this pin. One being the original BLACK/YELLOW wire and the other is a black wire going to this other relay. The relay has a RED/WHITE wire (LOW Fan speed) and a RED wire (12 const) and a brown. The red wire and the BROWN wire were cut and hanging out in the bay. So I soldered the red wire to the red wire going to pin A/05 and soldered the brown wire coming from the Radiator After Run Relay (SCREWED TO THE FAN SHROUD).

Finally, this separate relay originally had the big ground going to the after run relay (clipped to the fuse box) going into Pin 5 (middle).

As I type and think, I soldered the small brown wire going to pin 6 to the large one Pin 5 so it was not grounded. I then took the Pin 5 Wire (now 5 and 6) out of the relay and plugged it into the ground block on the side of the fuse box. So it seems that I should have kept pin 5 in the relay socket and grounded the small brown wire only.

Now correct me if I'm wrong but in my original US harness, the High Speed Fan Relay and the After Run Relay (Hi speed fan) were the SAME relay. There was no separate relay that is specifically called an After Run Relay, only a High Speed Radiator Fan Relay. And my 1986 Golf Diesel originally had an After Run feature.

[jhax]

I swear those fan circuit are possessed,  have a 92 eco diesel that wont turn on either , works with ac on, even runs 10-15  seconds after car is off, wontr run with ac off and let it get warm , changed temperature switch in radiator , tried bypassing it, traced allot of wires around , seems there is a signal from fuse and relay panel that isn't doing its job, finding accurate wiring for my car has been poor,  Not to mention i think i have a 3 speed fan..ahhhhhhhhhh

Its been like that for almost a year, but i run ac all teh time here in florida so it works great, I remember getting into this a while back and my conclusion is that there is a relay not turning it on for me and i couldn't find the right one nor a matching diagram of my fuse/relay box and gave up after guessing  at a few with no luck-

good luck with yours ,

Trust me sir....this site will save your life. http://www.autolib.diakom.ru/CAR/Volkswagen/1992/Jetta/WIRING%20DIAGRAMS/

[jhax]

BIG goings on this morning. I was pissed. So I swapped out the relay clipped onto the box for another one turned the car into the on position and the fan turned on. That made me happy...then i quickly became very VERY angry. Tried to start it, GP Temp Switch unplugged to get max effective glowness, wait 10 seconds, cranks really fast, like it's about to start but doesnt turn over. Try this several times with no luck. Just a lot of white smoke. Get 12.6V at the GP bus bar, 12V at the starter and 12V at the fuel cutoff switch. Jump it with my roommates vehicle. More white smoke, cranks faster and FINALLY starts. I jumped it at the battery terminals, I know youre not supposed to do that but I had no choice, just glad my battery is in back now. FIrst gear pulling out of my street, I gun it to get any fuel cleared out and it chokes once. Driving on the highway to work. I jump the fan to ensure it is working. Temp goes up, LED flashing (not in a pattern, but like it's shorting), GP LED acting up. I hit traffic and exit off at a gas station just to make sure everything under the hood is fine. Fan is still going, coolant overflow bottle is still just warm so I assume it's just the gauge. My fuel level gauge shoots from just over half to nothing right quick. I shut it off and Immediately turn it back on and it does so. I sit at the station for a bit deciding if it's really overheating or just the gauge. I go to turn it off again, turn the key off and the car is still running. Not running away climbing in RPMs running but idling. Finally say "FU*K IT" and drive the rest of the way to work. The coolant light only acts up when the throttle is pushed. Not acting up at idle. Make it to work stall it off, take the key out and the gauges still read like the car is on. So I disconnected the + battery cable and left it off in hopes that it will reset its self. I assume the gauges acting up was the result of jumping it at the + and - battery terminals. But this not starting issue really got to me. No idea what it could possibly be. Any thoughts?  The car didnt show any signs of mechanical troubles while driving. It ran smooth as could be.

Justin

[jhax]

Went to start it just now at work. The starter to fan splice was still plugged in and was causing the LEDs to act like the car was still on. Took it out and replaced it with the RD/WT and Green wire plug. Plugged in the relay that was working this morning. Glow Plug Temp Wire unplugged Ign on and it started right up. No issues. The fan was even running on low speed. I turned on my fan, fan didnt blow any air and was making a buzzing sound. The temp gauge LED started randomly blinking as did the GP LED. Fan turned off and the clipped on relay started buzzing at me. Constantly, I unplugged it and plugged it back in and it was still yelling at me. Still no rad fan. There is a solid plastic yellow hose that goes from the hose that goes to my brake booster into the firewall that broke, I assume this is why the interior fan doesnt run?

[GEE-BEE]

I run a after market fan and controller

Flexalite assy with a option on/off swith to turn the fan on or over ride for fan off when on the freeway and a/c is on..

GB

[jhax]

Yeah my next purchase will be a pusher fan. Looks like Ill just keep messing around with it.

[mtrans]

coolant overflow bottle is still just warm so I assume it's just the gauge.
Justin

I put clasic thermometer in overflow bottle.92 c on gauge and 82 c on thermometer,so now I know.

[jhax]

I drove to my parents' yesterday (about an hour with traffic and my dad IR temped the coolant system. The hottest was the upper radiator hose at 172*F. My car didnt have any issues starting until this morning when the same thing happened so I think Im going to just do the pimp your glow plugs thing today. put the big ground wire going to pin 5 of that inside relay back on pin 5 and re-pinned pin 6 with a thicker wire and grounded that. Still no change with the fan. I also left the little ground wire soldered to the big one and grounded it next to the fuse block, big mistake, it was pretty melted by the time I got to work. The big wire (pin 5) wasnt warm at all. I believe the reason I still dont have a fan is because the pinout on the relay is different than the one on the socket (ie Big brown pin 5 goes to 87a on the relay). This glow plug thing really does irk me. Oh, my dad and I checked yesterday, when the GP temp sensor was plugged in and the key turned to the on position, no voltage to the plugs at all, nor the light. Not sure if the sensor thought the coolant was still warm enough or what, but we had let it sit for a while.

Im pretty confident my glow plugs are shot as well. I went out into the parking lot at work to test one (#4), got it out of the head, grabbed some cables, neg and pos battery posts, neg on GP body and pos on threaded end. No glow, I could grab the plug. Not sure if that was the correct method, i have heard to use a charger.

[jhax]

Well turns out 3 out of 4 glow plugs were dead...damn autolites.