Rad Fan Not Kicking In..!!!!

[raj]

ok, now the cars idling is cured i thought id start a fresh thread for a fresh problem!

note: ive have done away with the swirlpot and fitted a campus matrix to waterpump bleed hose.
also both my stat and fan switch are std temp and my stat has a 3mm hole drilled into it to aid bleeding.

so the problem -

the rad fan does not want to kick in at all.! the temp rises past where the fan should kick in! i shut the engine off before the temp rises too high.!

ive tested the rad fan switch and its working with a multimeter.
the relay is also ok,
the fan works if i bridge the wires,
ive also bled the system.


just to add, the way i bled the system is as follows -

• fill rad up via the top rad hose until full, wait for the coolant to drop and keep on toping the rad up until its full.
• refit top rad hose to water pump.
• fill header tank and blow coolant through the system making sure to keep the header tank topped up, keep blowing the header tank until a constant stream of coolant flows out the highest bleed hose and lock the nipple off while still blowing in the header tank.
• start the car with the header tank cap off.
• fit the header tank cap.

does that sound ok or am i doing something wrong? also to add ive not used the top rad hose bleed nipple yet as i dont know at what point i should do so?? do i even need to as my stat has a hole in it???!!


what else can i look at or do differently?

[Sparkie]

where do you think the fan should cut in....?

[Chris Hebden]

I'd be taking out the bleed screws while the engines warming up, leave the expansion tank cap off untill really warm and raise the expansion tank as high as possible. Apart from that theres nothing different i would do!

[raj]

where do you think the fan should cut in....?

well going by the std gauge which has the bottom 1st marking,then 2nd,3rd and the 4th last.
im assuming the rad fan should be kicking just before the 3rd mark.?

the temp go past this soi turn the engine off when it reaches inbetween the 3rd/4th marks

[raj]

I'd be taking out the bleed screws while the engines warming up, leave the expansion tank cap off untill really warm and raise the expansion tank as high as possible. Apart from that theres nothing different i would do!

my header tank is at the highest point anyway = behind the scuttle.

also, am i right in thinking that no collant will flow out of the bleed nipples when the car is idling? im sure ive only ever had coolant come out when i give it abit of throttle.?

[Frix]

im assuming the rad fan should be kicking just before the 3rd mark.?

[Matt Cole]

I'd be taking out the bleed screws while the engines warming up, leave the expansion tank cap off untill really warm and raise the expansion tank as high as possible. Apart from that theres nothing different i would do!

? Leave the screws shut, your just dragging air in! Raj, let it warm right up untill the last mark before the group of marks. Check that your stat is opening (feel the the rad and pipes, should be hot all over). Let it cool and then bleed again.

[raj]

? Leave the screws shut, your just dragging air in!
Raj, let it warm right up untill the last mark before the group of marks. Check that your stat is opening (feel the the rad and pipes, should be hot all over). Let it cool and then bleed again.

im pretty sure the stat is opening as all the hoses get hot.

ill re-bleed the system tommorrow when the cars cooled. shall i just use the same method i posted above.? or shall i just start the car with the header tank cap off?

im abit confused as i cant see how i could have an air lock as the header tank is the highest point so surely if there was air in the system it would be routing itself to this point, right.?

[MR TURBO]

im pretty sure the stat is opening as all the hoses get hot.

ill re-bleed the system tommorrow when the cars cooled. shall i just use the same method i posted above.? or shall i just start the car with the header tank cap off?

im abit confused as i cant see how i could have an air lock as the header tank is the highest point so surely if there was air in the system it would be routing itself to this point, right.?

Not necessarily air locks are still possible as it is trapped air quote ( TRAPPED) But hey give it some good head 2m and ya should be fine

[Frix]

[quote=raj;37703]im pretty sure the stat is opening as all the hoses get hot.

ill re-bleed the system tommorrow when the cars cooled. shall i just use the same method i posted above.? or shall i just start the car with the header tank cap off?quote]

mate what you said seems fine, i tend to bleed the system differently.

with engine cold i hold the header tank as high as possible.
unscrew both bleed nipples
keep pouring water into header until you get a constant stream of water from nipples, as and when this happens fastern nipples up.
and all should be good!
start engine and check!

i remember seeing colin aka the master once trying to get an air lock out that was proving impossible.

used a standard header cap screwed it on and attached a bicycle pump to the cap and pumped any air thru!

worked a treat!!

[Brigsy]

A good way of testing for air locks is to put the heater on & see if it blows out hot air. Should be hot when half way on the gauge. If it blows cold there will be an air lock. This is assuming the heater matrix is ok!

Id let it go above the 3rd mark slightly, its not going to hurt anything. The std switch usually kicks in above the 3rd(3/4) mark.

Also check the rad is getting hot.

[raj]

A good way of testing for air locks is to put the heater on & see if it blows out hot air. Should be hot when half way on the gauge. If it blows cold there will be an air lock. This is assuming the heater matrix is ok!

Id let it go above the 3rd mark slightly, its not going to hurt anything. The std switch usually kicks in above the 3rd(3/4) mark.

Also check the rad is getting hot.

forgot to add - ive bypassed the heater matrix as its leaking. ive simply joined the 2 hoses together.


the rad gets hot, it will do anyway as ive mentioned ive drilled the stat.

[Brigsy]

If there are no airlocks the switch in the rad has got to be at fault, or of the wrong temp rating if it doesn't come on at all.

[RICHIE]

you can test the fan and wiring easy if you take the connecter off the temp switch and bridge the two contacts inside the connector with a piece of wire or paper clip ect if it doesnt come on the problem lies elsewere in the wiring.

[Nick k]

ok, now the cars idling is cured i thought id start a fresh thread for a fresh problem!

note: ive have done away with the swirlpot and fitted a campus matrix to waterpump bleed hose.
also both my stat and fan switch are std temp and my stat has a 3mm hole drilled into it to aid bleeding.

so the problem -

the rad fan does not want to kick in at all.! the temp rises past where the fan should kick in! i shut the engine off before the temp rises too high.!

ive tested the rad fan switch and its working with a multimeter.
the relay is also ok,
the fan works if i bridge the wires,
ive also bled the system.


just to add, the way i bled the system is as follows -

• fill rad up via the top rad hose until full, wait for the coolant to drop and keep on toping the rad up until its full.
• refit top rad hose to water pump.
• fill header tank and blow coolant through the system making sure to keep the header tank topped up, keep blowing the header tank until a constant stream of coolant flows out the highest bleed hose and lock the nipple off while still blowing in the header tank.
• start the car with the header tank cap off.
• fit the header tank cap.

does that sound ok or am i doing something wrong? also to add ive not used the top rad hose bleed nipple yet as i dont know at what point i should do so?? do i even need to as my stat has a hole in it???!!


what else can i look at or do differently?

How have you tested the fan switch with a multimeter? If you have bridge the wires and the fan runs then the fan switch is faulty. Fan switches can be abit strange when they decide to fail, work 1 minute and then give up. replace it raj then see what happens.

[raj]

How have you tested the fan switch with a multimeter? If you have bridge the wires and the fan runs then the fan switch is faulty. Fan switches can be abit strange when they decide to fail, work 1 minute and then give up. replace it raj then see what happens.

scoff gave me instructions on how to test the fan switch

for what its worth i think i will replace the rad fan switch. time to drop the coolant for the 4th time

[Nick k]

scoff gave me instructions on how to test the fan switch

for what its worth i think i will replace the rad fan switch. time to drop the coolant for the 4th time

If you have quick hands you don't loose alot of coolant

[Sparkie]

personally i'd stop all this d1cking about.

and wire it like this.

alternator +ve to rad fan switch.
rad fan switch to rad fan +ve.
alternator -ve to rad fan -ve.

done.

[raj]

personally i'd stop all this d1cking about.

and wire it like this.

alternator +ve to rad fan switch.
rad fan switch to rad fan +ve.
alternator -ve to rad fan -ve.

done.

i dont understand non of that..! me and electrics plus the fact i dont want to alter something that SHOULD work as it is. id rather find the fault than diverting.

[Matt Cole]

personally i'd stop all this d1cking about.

and wire it like this.

alternator +ve to rad fan switch.
rad fan switch to rad fan +ve.
alternator -ve to rad fan -ve.

done.

Although i wold put an inline fuse in there too sparkie.

[Nick k]

Although i wold put an inline fuse in there too sparkie.

The start up current from the fan motor will burn out the fan switch for sure after a short time Hence the relay!!

[Matt Cole]

The start up current from the fan motor will burn out the fan switch for sure after a short time Hence the relay!!

Na mate, its been tried and tested many times.

[raj]

hmm, how do i decipher this electrical chitchat

[tom t]

mines now bloody playin up. gana have to look 2moro. hoping just a loose connection. or air in the system.

[Harrison01]

dont worry raj i had exactly the same problem with the switch yesterday. all my wiring metered out fine, but found that if i pushed/pulled the connector plug on the switch it would work. so i had dodgy contacts.

def gonna do that wiring mod..

[raj]

dont worry raj i had exactly the same problem with the switch yesterday. all my wiring metered out fine, but found that if i pushed/pulled the connector plug on the switch it would work. so i had dodgy contacts.

def gonna do that wiring mod..

the thing is, i dont use the original connectors for the fan switch or the fan. im using spade connectors wrapped in heatshrink.

id look into doing the wiring mod but i cant make sence of it all this +ve -ve i need clearer instructions as im really not confident bodging wires together etc

[Sparkie]

personally i'd stop all this d1cking about.

and wire it like this.

alternator +ve to rad fan switch.
rad fan switch to rad fan +ve.
alternator -ve to rad fan -ve.

done.

red wire from alternator positive to rad fan switch.

red wire from rad fan switch to red wire on rad fan.

black wire from alternator negative (ground) to black wire on rad fan

[raj]

red wire from alternator positive to rad fan switch.

red wire from rad fan switch to red wire on rad fan.

black wire from alternator negative (ground) to black wire on rad fan

where exactly are the alternator +&- located.?

also what exactly will the above do.? will it change the way it works.?

[Nick k]

Just change the fan switch raj. If it does'nt fix it then start looking at the wiring.

[chrisb]

First post!

My water temp gauge had been showing that the car was running a bit hotter than normal for this time of year, i fitted a lower temp rad fan switch (k-tec) a couple of years ago but the rad fan used to kick in less frequently, so i figured the fan switch was faulty, i put the original switch back in and now everything is ok.
I also wired up a manual switch just in case the engine gets hot but i haven't had to use it so far! I also fitted a lower temp thermostat but that seems to work ok.
From the marks on the temp gauge (1'st being the horizontal base mark), the car should not go above the 3'rd mark around town or on the motorway, the needle should sit halfway between the second and third mark.

[raj]

First post!

My water temp gauge had been showing that the car was running a bit hotter than normal for this time of year, i fitted a lower temp rad fan switch (k-tec) a couple of years ago but the rad fan used to kick in less frequently, so i figured the fan switch was faulty, i put the original switch back in and now everything is ok.
I also wired up a manual switch just in case the engine gets hot but i haven't had to use it so far! I also fitted a lower temp thermostat but that seems to work ok.
From the marks on the temp gauge (1'st being the horizontal base mark), the car should not go above the 3'rd mark around town or on the motorway, the needle should sit halfway between the second and third mark.

i know all this already mate, doesnt help my problem but nice 1 anyway im going to fit another std fan switch and go from there

oh and welcome to the club

[youngscottie]

what rad are you using?
just a thought if its not the standard 5 item

[chrisb]

New poster! (less than 10 posts)

thanks for the welcome raj, looking forward to lots of helpful advice and knowledge from you guys

[raj]

what rad are you using?
just a thought if its not the standard 5 item

your right, im not using a std gtt rad. im using a MUCH bigger 1.9d extra van rad.
it has the same rad fan fitment as the gtt.

also while on the subject. is there anyone else that has this rad fitted that has also got the there header tank located behind the scuttle?

i ask this as im wondering if the coolant flow acts in a different way when you have the header tank sat in the scuttle and a bigger rad fitted..?

obviously im having to put a little more coolant in as the 1.9d rad has a larger capacity but whats happening is - from cold when i start the car the level is at the "min" mark on the header tank, wheni start the car and the coolant starts to flow the header tank will fill up to just under the max line! thats abit strange dont you think

i think the amount of coolant in the system is more than enough! it swallowed up a whole 5lts of coolant!! im sure the std capacity is 3.6lts? but as mentioned im putting this down to the larger capacity rad! does that sound right.

[gtmatt]

there is also a relay involved on the rad fan circuit ,sumtimes the relay can be at fault

[c5 swh]

To me it sounds like a airlock in the system, My fan would not kick in until the airlock was gone.

My header tank as been moved to behind scuttle and it took me ages to bleed system properly.

When i did mine as it got warmer the collant level rised until it came out top off the header tank, it would then drop. I kept topping it up as it did it and then it just kept still at the max mark.

[raj]

there is also a relay involved on the rad fan circuit ,sumtimes the relay can be at fault

the relay cant be at fault.! i can get the fan to work when the wires are bridged. so that rules the relay out.

[raj]

To me it sounds like a airlock in the system, My fan would not kick in until the airlock was gone.

My header tank as been moved to behind scuttle and it took me ages to bleed system properly.

When i did mine as it got warmer the collant level rised until it came out top off the header tank, it would then drop. I kept topping it up as it did it and then it just kept still at the max mark.

im hoping it is an air lock. but how to remove it the airlock is another problem

ive tried bleeding the system as you would but its made no difference.
maybe its a cheeky feckin airlock hiding somewhere!!
would the airlock be sitting around the radfan switch? if so,how? i thought air is suppose to rise to the highest point??mine being the header tank!
i also thought it would be easier for air to route itself out the system as ive got a drilled stat!!?

...and i was told it would be easy bleeding the system with a drilled stat and the header tank being at the highest point

[Mr_Dave]

Raj, I fitted a mahoosive rad to mine and had the same problems. Flicked the manual fan switch as I thought it was getting too hot. Couldn't find a fault anywhere. It was MOT time, so I knew I had to get it workin as the geezer was bound to overheat it or somethin....!

I took off the fan switch and chucked it in a pan of boiling water and got the multimeter out.... all was fine.

It just seems that the extra capacity/heat loss capability of the larger rads lets the temp rise just that bit higher at the back of the waterpump (where the gauge sensor lives) before it kicks the fan in. Mine was a bit further past the 3rd line than I'd liked. Its an 83 switch too.

[raj]

Raj, I fitted a mahoosive rad to mine and had the same problems. Flicked the manual fan switch as I thought it was getting too hot. Couldn't find a fault anywhere. It was MOT time, so I knew I had to get it workin as the geezer was bound to overheat it or somethin....!

I took off the fan switch and chucked it in a pan of boiling water and got the multimeter out.... all was fine.

It just seems that the extra capacity/heat loss capability of the larger rads lets the temp rise just that bit higher at the back of the waterpump (where the gauge sensor lives) before it kicks the fan in. Mine was a bit further past the 3rd line than I'd liked. Its an 83 switch too.

thats sounding exactly like the problem im having!!!

how did you sort it.? i dont like the temp going past the 3rd line at all.
with all my other 5s using the std rad/stat/fan switch the temp never went past 2 and a half on the gauge and the rad fan hardly use to kick in.

although the std rad is very good i dont want to resort back to it with all the hard work ive put in to the 5 to get it to where it is now

[Mr_Dave]

I just left it to be honest mate. I've got a really powerful Spal fan on there, so it whips the temp down quick smart as soon as it kicks in. When you're rolling, it never gets anything near that hot anyway, even at the track. Besides, when I'm gunning it, I flick the manual switch - I've got a frontera intercooler in front of the rad, so the fan chills that down too

The only time it'll get that hot is ticking over at the MOT garage, I drive the fan myself the rest of the time

Guess the fix is to either get a lower temp or adjustable switch, or leave it there filling in the hole, and get one of them ones that you can fit into one of the water pipes - pick one thats leaving the engine, not a return from the rad!

[raj]

I just left it to be honest mate. I've got a really powerful Spal fan on there, so it whips the temp down quick smart as soon as it kicks in. When you're rolling, it never gets anything near that hot anyway, even at the track. Besides, when I'm gunning it, I flick the manual switch - I've got a frontera intercooler in front of the rad, so the fan chills that down too

The only time it'll get that hot is ticking over at the MOT garage, I drive the fan myself the rest of the time

Guess the fix is to either get a lower temp or adjustable switch, or leave it there filling in the hole, and get one of them ones that you can fit into one of the water pipes - pick one thats leaving the engine, not a return from the rad!

ive got a 16" spal fan fitted to the rad.
thing is,although ive recently rebuilt this engine,the car hasnt seen the road in over 5yrs.

[Mr_Dave]

Tell me about it! I didn't have the balls to let it get that hot until after I had the switch in some hot water, and I was 100% that it was working! Even then, I wasn't happy about it.

Test the switch, if its working... look at something like this

http://www.demon-tweeks.co.uk/produc...pcode=GLORREFC

[raj]

Tell me about it! I didn't have the balls to let it get that hot until after I had the switch in some hot water, and I was 100% that it was working! Even then, I wasn't happy about it.

Test the switch, if its working... look at something like this

http://www.demon-tweeks.co.uk/produc...pcode=GLORREFC

that sounds like an idea! i can fit that just after the stat yes? im assuming you use your exsisting fan switch wires on it too.?

and yes,i have tried the fan switch in boiling water using a multimeter and it works as it should
....still,im going to try another fan switch before i go purchasing something that costs that much

[raj]

just a quick question,sorry if it sounds daft.....
when looking at the std temp range on a fan switch which is 92/82 deg c if im not mistaken?(thats what i have). what exactly do the 92/82 mean?
....does it mean - fan switches on @ 92deg.c and switches off @ 82deg.c?

also, out of interest, does anyone have ANY idea as to what/which fan switch it is that is classed as the low temp fan switch.?
low temp one is a 78/65deg.c i think.? surely the tuners cant be having these specially made for them so im assuming they are fitted to another car as a std switch?? but what car?

i know theres a peugeot one that has the same m22x1.5 thread size and has a temp range of 82/68deg.c

[Frix]

just a quick question,sorry if it sounds daft.....
when looking at the std temp range on a fan switch which is 92/82 deg c if im not mistaken?(thats what i have). what exactly do the 92/82 mean?
....does it mean - fan switches on @ 92deg.c and switches off @ 82deg.c?

also, out of interest, does anyone have ANY idea as to what/which fan switch it is that is classed as the low temp fan switch.?
low temp one is a 78/65deg.c i think.? surely the tuners cant be having these specially made for them so im assuming they are fitted to another car as a std switch?? but what car?

i know theres a peugeot one that has the same m22x1.5 thread size and has a temp range of 82/68deg.c

yep it means fan switches on at 92 degrees and turns off at 82 degrees

low temp fan switches on at 78 degrees and turns off at 68 degrees!

as for what car, i couldnt answer that one mate!

hope you get this sorted mate!

[Frix]

im hoping it is an air lock. but how to remove it the airlock is another problem

ive tried bleeding the system as you would but its made no difference.
maybe its a cheeky feckin airlock hiding somewhere!!

raj if it is an air lock have you tried using a bicycle pump ( rather than blowing thru it)with a header tank cap attached to it mate, just pump the air lock out!

might be worth a try!!

[Tiny Tim]

Raj, get yourself an 'Eezi bleed' kit from ebay/halfords. Job done.

[raj]

hmm.ive just bought a rad fan switch thats got a range of 88/79deg.c compared to the low temp switch which is 78/65deg.c so its sort of inbetween a std and low temp switch.
now i dont plan on changing my stat,but can someone tell me the std stat temp range.?

[Frix]

standard is 92/82 degrees, i think, someone will confirm!