cd.thomson
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| posted on 10/3/10 at 06:56 PM |
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fan rage
Firstly, can I just start by saying that CBS came good with my fan switch issues and have sent me a free one after discussing my wiring etc and
deciding it must be a faulty switch.
Secondly: unfortunately for me, unless im very unlucky and the new switch is also broken, its doing exactly the same thing.
Can someone please help?! this is my last underbonnet job!
Fan is wired as follows:
"fan supply" wire from premier loom to one side of thermostatic switch (mounted in a hose adaptor), wire from other side of the switch to
pin 86 on a 4 pin relay.
pin 85 is then earthed at the same place on the chassis as the fan earth.
pin 30 is receiving "always on" power straight from the battery via a 30amp fuse.
pin 87 goes to one side of the fan.
Im sure this is all okay, so why is my fan continously on??
tried two different relays and two different switches, also tried earthing the switchs on the chassis
[Edited on 10/3/10 by cd.thomson]
Craig
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Paul (Notts)
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| posted on 10/3/10 at 07:12 PM |
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can you test to see if the output from the switch to pin 86 is 12v
if it is then the fan will be on.
have you a link to the switch you are using.
Paul
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Cousin Cleotis
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| posted on 10/3/10 at 07:13 PM |
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when you disconnect the switch does the fan stop running?
try disconnecting either side of the switch does the same thing happen?
are you using a 4 pin relay?
You might want to put a test light on instead of the fan, if its an open design.....
Paul
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mad-butcher
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| posted on 10/3/10 at 07:17 PM |
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easy way I would check it is fan feed to one side of thermo switch other side to fan feed then other side of fan to earth, and see if fan still runs,
if not then put thermo switch in boiling water and see if it comes on when temp is up, that way it points to relay wiring.
mind you mine doesn't have a relay
tony
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James
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| posted on 10/3/10 at 07:27 PM |
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You sure you need a relay on the fan?
I don't have one with my Premier Loom. Nothing's burnt out yet! 
I have a manual fan switch as well and after taking advice didn't fit a relay here either.
Cheers,
James
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"The fight is won or lost far away from witnesses, behind the lines, in the gym and out there on the road, long before I dance under those lights."
- Muhammad Ali
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cd.thomson
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| posted on 10/3/10 at 07:30 PM |
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yes, im getting 12v between the feed to 86 and the battery negative.
The fan stops if either/both the switch terminals get disconnected.
its got to be the switch surely? but i cant ask for another free one and theyre £15 a pop so what keeps burning the pins together??
http://www.cbsonline.co.uk/fan-switch-10095c-m14-x-15-fansw2-3528-p.asp
Craig
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cd.thomson
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| posted on 10/3/10 at 07:31 PM |
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james, im only fitting a relay on the recommendation of CBS who supply the fan switch.
the guy there suggested the only real way to break these switches was to burn them out by directly connecting it to a fan!
He was also pretty certain it should use a 4 pin relay
[Edited on 10/3/10 by cd.thomson]
Craig
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2cv
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| posted on 10/3/10 at 07:35 PM |
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From what you have said, your wiring is correct for the fan and the relay.
This surely suggests that either the switch is faulty or the relay is faulty. If you have a multimeter you could set it to resistance and see if, with
no cable sonnected to the relay, there is connectivity across pins 30 and 87. If there is it is a faulty relay. You can do the same with the two pins
on the fan swtch. They should only connect when the set temp has been reached.
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Cousin Cleotis
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| posted on 10/3/10 at 07:56 PM |
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It really does sound like its got to be the switch or relay, but two faulty switches and relays? not likely, but stranger things have happened.
Ive had some wierd wiring faults that i dont understand, but i would try earthing the relay to the chassis and putting the positive from the loom
throught the fan switch.
Paul
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flak monkey
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| posted on 10/3/10 at 08:09 PM |
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Yes your wiring is correct.
Stupid question but are you sure you have identified the pins on the relay correctly? Its easy to mix them up....
David
Sera
http://www.motosera.com
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cd.thomson
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| posted on 10/3/10 at 08:10 PM |
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just heated the damn thing up with a blowtorch. right on queue at approx 100degrees the blooming fan turned off!
i knew i must have been given some incorrect information at some point!
can anyone advise how to wire the switch and fan so that it only comes on when the switch opens (rather than closes) at 100?
and everyone: thanks for the wisdom and patience
[Edited on 10/3/10 by cd.thomson]
Craig
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flibble
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| posted on 10/3/10 at 08:22 PM |
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I can post you a 5 pin relay if you like? (like the one in your water level thread a while ago) If it'd be of any use, gives you the 87a pin
which is what it seems you need. (If I get what's happening  )
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flak monkey
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| posted on 10/3/10 at 08:23 PM |
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You just need a changeover relay:
Wiring as your current one but just use terminal 87a to connect to your fan.
That way with the switch closed it will hold the relay with pin 87 connect to nothing. When the switch opens, the relay will turn off and the fan will
come on.
David
Sera
http://www.motosera.com
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cd.thomson
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| posted on 10/3/10 at 08:26 PM |
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thank you gentlemen
Craig
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omega 24 v6
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| posted on 10/3/10 at 09:36 PM |
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Just exactly what I said on your last post.
Fozzie can we have a smug Barsteward emotcicon (sp) please.
hey at least you've got it working now though.
[Edited on 10/3/10 by omega 24 v6]
If it looks wrong it probably is wrong.
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Paul (Notts)
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| posted on 11/3/10 at 07:11 AM |
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not thought this statment trhrough BUT...
if he uses a 5 pin relay with his current set up would this result in the fan turning itself on when he turns the ignition off...?
Paul
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flak monkey
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| posted on 11/3/10 at 07:14 AM |
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quote:
Originally posted by Paul (Notts)
not thought this statment trhrough BUT...
if he uses a 5 pin relay with his current set up would this result in the fan turning itself on when he turns the ignition off...?
Paul
Er, yeah quite right. The fan needs to be on a switched supply too not wired direct from the battery
Sera
http://www.motosera.com
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cd.thomson
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| posted on 11/3/10 at 08:06 AM |
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oh dear, I dont know where I can take switched power from unfortunately.
the electrics is all pretty much black magic to me
Craig
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cd.thomson
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| posted on 11/3/10 at 08:09 AM |
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quote:
Originally posted by omega 24 v6
Just exactly what I said on your last post.
Fozzie can we have a smug Barsteward emotcicon (sp) please.
hey at least you've got it working now though.
[Edited on 10/3/10 by omega 24 v6]
i made sure I checked with CBS twice that I only needed a 4 pin after your post omega, i wasnt ignoring you!
Craig
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omega 24 v6
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| posted on 11/3/10 at 12:45 PM |
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No worries mate.
As for your NEW problem then you could add an additional relay into your fan supply line.
so the live cable to your fan relay ( pin 30 )
needs cut before it goes to the relay leaving you with 2 cable ends. Conect them to pins 30 and 87 of a 4 pin relay.
connect pin 86 to earth and connect pin 85 to an ign feed ( coil perhaps) or trace an ign feed using a meter or test light and splice into it. As
you're only powering a relay the extra load to that circuit is minimal.
If it looks wrong it probably is wrong.
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02GF74
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| posted on 11/3/10 at 01:45 PM |
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quote:
Originally posted by cd.thomson
just heated the damn thing up with a blowtorch. right on queue at approx 100degrees the blooming fan turned off!
then that makes the switch N.C. (normally closed) and you want N.O. (normally open).
You want intermotor part 50041
closed 95 and opens at 90.
send the switch back - don't complicate things with switch over relays bladdy blah.
bad news is they cost £ 22, which is what I paid for mine, but pretty sure some them on ebay for £ 16. 
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02GF74
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| posted on 11/3/10 at 01:50 PM |
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quote:
Originally posted by flak monkey
Wiring as your current one but just use terminal 87a to connect to your fan.
That way with the switch closed it will hold the relay with pin 87 connect to nothing. When the switch opens, the relay will turn off and the fan will
come on.
David
that is all fine and dandy but usually the fans are wired to permanent live (as I belive the OP described) so when ignition is off, the fan will come
one; not great for when it comes to starting the car the next day.
as previous poster said, get the proper N.O. switch.
PS is it time for a new avatar?
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cd.thomson
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| posted on 11/3/10 at 01:53 PM |
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thanks 02G,
would you happen to know if these are m14 x 1.5?
Craig
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flak monkey
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| posted on 11/3/10 at 05:18 PM |
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Why would you put a fan on a permanent live? I hate having things on them as its just asking for something to go wrong at some point.
I know some people reckon that the fan running on after the car is switched off helps, but it makes virtually no difference as the water is no longer
being pumped.
The only permanent lives on mine is the horn and feed to the immobilser and hazards. Everything else is switched
Sera
http://www.motosera.com
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02GF74
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| posted on 11/3/10 at 09:03 PM |
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quote:
Originally posted by flak monkey
Why would you put a fan on a permanent live? I hate having things on them as its just asking for something to go wrong at some point.
I know some people reckon that the fan running on after the car is switched off helps, but it makes virtually no difference as the water is no longer
being pumped.
The only permanent lives on mine is the horn and feed to the immobilser and hazards. Everything else is switched
AR%% and F***K - typed in repsonse, lost conn, the nagain but daved it, great, same to paste it and insteadcopid it!!!
3rd time lucky
one word: siphonic action.
thermostat will be open after hardf run; fan on cools water, creates flow in system due to cold water sinking to bottom of radiator.
yes, M14 1.5
aslo why waste power, yes it is mA, to keep contact open when that power can be used for forward motion?
saving to file now. grrrrr
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