fan switchl

Post by **special** » 10 May 2005 10:26 pm

help my car is getting though fan switches at a stupid rate this is the second one ive fitted in a month i know its the fan switch thats acting up cos ive tested it (by fan switch i mean the one in the rad that switches the cooling fan on ) the fan works for a couple of days then packs in 3 in two months is silly theres a problem somewhere

my car is a 1.4 manual
please help me

Post by **5lab** » 10 May 2005 11:41 pm

is the car actually overheating? 340 fans come on famously late

Post by **morgan105** » 11 May 2005 09:00 am

Have you tried testing the switches with a voltmeter, take the switch out and gently heat the element, in the base of a dry pan over a burner or immerse the element end in a shallow bit of water and bring up the temp, all while testing with a meter. This will tell you if the switch is working and if you use a thermometer to read the temp as it rises this will tell you at what temp the switch activates.

As Slab said, they are known to come on late.

morgan105

Post by **special** » 11 May 2005 09:05 pm

yes the car is over heating and yes ive also cheaked that the switch works and yes it does but then it packs up

Post by **redline** » 11 May 2005 11:10 pm

when you come down for the seats and door cards you can have the rad and switch as well its for a 1.7 but should be ok

Post by **5lab** » 12 May 2005 12:24 am

agreed, same radiator so should be fine

Post by **special** » 12 May 2005 04:53 pm

i dont think you lot understand

my car was overheating last month because the fan was not kicking in so i cheaked the fan switch by hooking it up to a multimeter and puting it in to boiling water
the switch did not work so i bought a new one the fan then started to work 2 weeks later the fan had stoped kicking in again so i cheaked the new switch in the same way as the old one
the new switch was not working so i went and got a second new one
the fan started working again hurrah
then it stoped again i tested it and that one is now duff

so my question is whats causing 3 fan switchs to stop working

Post by **special** » 13 May 2005 05:22 pm

i take it were all stumped on this one then

Post by **pettaw** » 13 May 2005 07:05 pm

I wonder whether the fan motor is partially seized and therefore drawing too much current and melting the internals of the switch in the fan, AFAIK all the power to the fan has to go through that switch. Maybe give the fan a good check over and make sure its free to move properly.

Post by **special** » 14 May 2005 07:15 am

thanks ill cheak in to that the fan did seem a bit hesitant when i was watching it

Post by **5lab** » 14 May 2005 11:05 am

check all the fuses are the right rating in your fuse box too

Post by **foggyjames** » 16 May 2005 07:12 pm

It's bound to be relay driven - try replacing the relay with a scrapyard-special (or shock, horror even a NEW one!). A dodgy fan will take out the relay before the temp sender.

cheers

James

Post by **pettaw** » 21 May 2005 09:21 pm

Its not driven by a relay. its direct. (Just checked on the wiring diagram)

Post by **foggyjames** » 21 May 2005 11:45 pm

Actually, this is Volvo...I can well believe that! Very odd though! I take it this was green-book material?

cheers

James