not so cool

davy83

Member
Messages
2,809
As those of you who were on the 20th anniversary trip will know I have a problem with my 3200 getting too warm when sitting in traffic. Its not a problem in Aberdeen as its always cold here. I am just digging into this and have worked out that the second cooling fan never comes on, so that's the source of my problem right there (I think). However, first does any one know if these are 12v fans and indeed if they are other than just simple motors? I plan to try and test the motor. The other thing that's odd is the first fan comes on far too soon before the car is warm really and it increases in speed once the engine reaches the temperature when I would expect it to cut in. I replaced the wee daft resistor down behind the grill about 4 years ago, but I may have a look at it again just in case.
Does anyone have a description of how the logic of the cooling system works? I have searched my printed manual and cant find a section on it and yet I am almost certain I have seen it some where.
Any opinions and suggestions welcome!
 

77GR

Junior Member
Messages
76
I'm not sure how the 2 fans talk together but one thing I do know is that the fan(s) don't just come on for the water temperature. If the Air Con is switched on (as in "ECO" is Off) then the fans will cut in once gas pressure is achieved to help cool the condenser irrespective of water temperature. Thus, if you start the car from cold and the air con is on, the fan(s) will cut in and out relatively quickly because of the air con pressure way before they are needed to cool the water system - the water radiator will remain cold because the thermostat is restricting flow until the engine warms up properly.

You obviously still have a so far unfathomed problem with one of the fans (which I can't commen t on myself) but don't get too worried about the early cut in if the air con is switched on - in fact, make sure it is turned Off ("ECO" is On) before running detailed fan/cooling diagnostics to remove the air con factor.
 

davy83

Member
Messages
2,809
Thanks Graham, I generally have the AC on all the time as it helps demist and the car seems unhappy with it off but yes I might let it warm up again with the AC off and see how that goes, but I suspect the one fan never cutting in at all is my biggest problem. Thanks for that it explains the one fan coming on early.
 

Trev Latter

Member
Messages
1,213
It's in a not obvious place. Fuel Supply section, page 25. There's a little more info either side of it. If you can't find it, shout out and I'll post it for you.
 

Trev Latter

Member
Messages
1,213
No worries. On the face of it, you may have a pressure switch issue, but that should be pretty easy to diagnose with a break out cable on the plug and a multimeter. The worst bit is access to the switch as it's behind the offside headlamp.
 

madmanmart

Member
Messages
377
I’ve had two 3200 now with a failed fan. Take them off and bench test each one.

There’s a resistor down by the fans that controls if one or both come on. These often fail also.
 

davy83

Member
Messages
2,809
Ok so I have it fixed.
I replaced the 50A relays and checked the two big fuses, I tested the old relays and they seemed to be working, so this was not the issue
The fans are 12 V DC and I tested both with a DC power supply and they were both working
fan burned connect.jpg
However the connectors for both fans were not good. One was badly burned up and this was the one not working. and the other had been replaced with a random connector that was not water proof.
So I replaced both connectors sourcing replacements from http://www.vehicle-wiring-products.eu/product.php?xProd=1237
Had to dismantle a few things to get enough room to get in and crimp the new contacts on. but since I have the right crimp tool it was reasonably straight forward

IMG_20181116_150125.jpgfanconnect1.jpgfanconnect3.jpg
 

Oneball

Member
Messages
11,075
Glad you got it fixed. Going to have to sit on a stool in front of mine and see if both fans kick in now.