Volvo AWD 850 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 5/2004 850 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

1994 850 cooling fan problems 850 1994

posted by  mintchaser on  Sat Sep 4 09:24 CST 2010
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Fri Sep 24 12:28 CST 2010
[RELATED]

just found out the cooling fan on my trusty 850 isn't functioning sitting at traffic lights the other day.
I have figured out the wiring and the relay etc,and tested the coolant sensor off the car,which checks out fine for resistance and temperature.
the fan itself works at both speeds, using a direct connection from the battery,and the relay itself is working as it should.
The car as no AC which from what I have read can be part of the fans function.
The two feed wires coming from the ecu, to the relay are not producing any voltage,right up to the point of when the coolant almost boils,could this just be the wiring or the ecu itself that is past it,or is their a component in the ecu itself like a small relay that could be replaced.
The main power,a red cable that leads to the battery is getting no power,but for the life of me I can't find the fuseable link,running a feed straight from the battery to the power point produces no fan action.
I get the feeling with this problem, it might a case of rigging up some sort of thermostatic switch to turn the fan on and abandon the original system.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    1994 850 cooling fan problems 850 1994

    posted by  KlausC on  Sat Sep 4 14:23 CST 2010
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Fri Oct 24 10:15 CST 2014
    [RELATED]


    Did you check codes on A-2??? If you plug in A-2, and then hit the little black button 3 times, that brings up a self test. Part of the self test is to run the fan at low and high speed for 3 seconds.


    Thermostat Opens
    Starts (2) ............................... 186F (90C)
    Fully Open .............................. 216F (102C)
    Turbo thermostat starts opening at 180  F (87  C).

    Unless you have noticed the instrument panel temp gauge going up, the fan is working OK.

    The yellow/white wire from the ECU to the relay is for low speed, the yellow wire is for high speed. Power is only supplied to either when the ECT signals the the ECU that the temp range is too high, around 216F for low speed.
    The red wire to the relay is fused and always HOT. The red and green wire to the fan is for high/low speed.

    So you need to check the fuse box, somewhere, because you have no power on the red wire.

    Klaus

    --
    Two great Volvos, a 1967 220 and a 1998 V70R








    •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

      1994 850 cooling fan problems 850 1994

      posted by  mintchaser on  Sun Sep 5 00:07 CST 2010
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Fri Sep 24 12:28 CST 2010
      [RELATED]

      Checked the self test on the a2 socket no signal from the ecu on either the high or low speed wires,although this did check out just after xmas.
      Definately no power on the main red lead,but the fan doesn't operate with a patch lead to the battery using the self test.But power to the relay pins makes the fan trip in on both settings with the patch lead







      •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

        1994 850 cooling fan problems 850 1994

        posted by  KlausC on  Fri Sep 17 07:21 CST 2010
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Fri Oct 24 10:15 CST 2014
        [RELATED]

        I just looked at my 1998 V70. There are 2 fuse boxes under the hood, the one with a lot of fuses and another with relays and large fuses (just forward of the other fuse box.

        In the fuse box next to the strut tower is a fuse for the cooling fan. It is 60Amp.

        Klaus







  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    1994 850 cooling fan problems 850 1994

    posted by  tmannian on  Sat Sep 4 10:33 CST 2010
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Sat Sep 20 10:31 CST 2014
    [RELATED]

    there is a fuse between the starter motor and the relay. It is possible that the fuse has blown. I can't recall if this would also affect the thermostat.

    You only directly connected positive right? So the ground is good.

    The fan shouldn't start until 102C which sucks because the coolant boils somewhere near 115-125. Not a huge amount of leeway...






<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.