cooling fans not...

Newbie Joined: 18 Jun 2006 Posts: 1

cooling fans not coming on when there suppose to? I,ve changed thermo stat, and thermo switch, i,ve checked the fans work(by shorting out pins) have also checked the three relays and they are ok.. i,ve flushed the radiator out and the matrix does,nt seem to be blocked....so can any one suggest something that i can do please..... as driving around in the dead of night to avoid traffic congestion is starting to affect my others halfs sex life..... :?

Level 6 User Joined: 10 Nov 2005 Posts: 149

i had that same problem.. turned out to be the white wire from the fan switch to the relay.. the wire was "almost" broken, so if the relay was not connected, there would be signal, but not enough current to drive the relay.. replaced wire and all was fine...

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

if the fan works when its shorted then there can only be the temo sender, either its not workign or your notlettign it get hot enough to kick in.

Level 6 User Joined: 10 Nov 2005 Posts: 149

well, the easiest way to check if its the wire or not is to take the plug off the temp switch and short the white wire pin in the plug to ground (shorting the black one will not yield anything, but wont cause any damage either).. if the fan runs, the white wire is ok.. if the fan also runs by shorting the 2 pins in the plug, then both the white and black wires are fine (black one is connected directly to ground).
if the fan is still not running, and the fan and relays are ok, then theres the 2 fuses, one inside the car that drives the fan relay and one in the engine compartment fusebox that drives the fan through the relay. check this stuff out. important thing here is, if its a wire, it's not always enough measuring the voltage, since it can look perfectly fine as long as there's no load, but as soon as theres load, the voltage drops if only a few cores in the wire are connected.. hope this makes sense... and trust me, i know... i've had the problem on my own car and am an electrical engineer, so i should know what i'm talking about Smile

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

he said in his post if he shorts it out it works!

On the very 1st line!

Level 6 User Joined: 10 Nov 2005 Posts: 149

i know, chris.. question is, if he shorted it at the switch, at the relay or somewhere else.. but i guess we will know when he returns and posts again Wink

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

well 99% don't know that irts relay activated so he will have done it at the switch.

Retroholic Joined: 23 Dec 2005 Posts: 3315

my aux water pump aint working how can i check thas fooked?(fitted a new relay as it was missing) and is it air filter side down below the rad?? off topic but thanks in advance....

Level 6 User Joined: 10 Nov 2005 Posts: 149

the aux pump is indeed on passenger side below rad/air box.. the relay is the left one looking into the relay/fusebox from the left side of the car, but i guess you know since you changed it already.. i think one of the 4 fuses in there are for the aux pump as well..

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

check the wires to the pump as they very often are broken, the pump istelf may be siezed solif as well.

Retroholic Joined: 23 Dec 2005 Posts: 3315

hooverphonique";p="99974 wrote:

i think one of the 4 fuses in there are for the aux pump as well..

fueses in the black box by relay? any inside the car?

anyway of powering the aux pump to see if it is working?

Level 6 User Joined: 10 Nov 2005 Posts: 149

yes.. fuses in the engine compartment relay/fusebox.. it has 4 fuses, there should be a symbol on the sockets telling what they do...

ehm.. well, you can power the pump directly at the connector on it to check wiring.. the pump will do a 7-8min run if you remove the relay from its socket and reinsert it, if fuses, pump and wiring is ok.. regarding fuse inside the car, i don't remember, but considering there is one for the fan relay there could very well be one for the pump relay as well..