Coolant temperature too high warning message on a D9 406

Foghorn Leghorn · Post by **Foghorn Leghorn** » Sat Sep 09, 2006 9:09 pm

Ok ladies and gents welcome to the very first of Fogs howto guides

Firstly confirm that you have coolant and that the car isnt overheating. Now turn off the air conditioning, if the STOP light goes out and the car stops beeping at you then all is good, there is nothing wrong with your coolant and coolant temperatures, infact the warning will still come up if the engine is off

This is quite a common problem and usually means your fan, fan speed resistors or relay have thrown in the towel (damned quitters

)

Pop the bonnet up and remove the centre grill with the Lion badge.

Start the car and turn on the air con, check to see if your fan is running, if it is stopped then the fan, one of the relays or the wiring is faulty.
If the fan starts, stops, starts stops etc then it is most likely one of the two resistors.

Turn the car off and unplug the fan, check it turns freely, then using a DVM measure the resistance across the pins, if it reads 0 ohms or open circuit then its a duffer, otherwise all ok.

Next check the resistors, remove the plugs and undo the screw holding them in place, visually inspect the resistor (coil of wire) and give it a prod, I found that mine had corroded through thus becoming open circuit and preventing the fan from running at full speed. Do this with both resistors in turn.

Now check the relays, remove the clip on cover on the right hand side. there are several relays, starting at the top unplug and test one by one. To test use a DVM to measure the resistance across the coil of the relay (look on the side of the relay for the pin numbers) if the coil measures 0 ohms or open circuit then shes a duffer. It is also a good idea to measure the contact resistance between the common pin and the NO and NC pins of the relay, these should be less than 1 ohm, if not, then best to replace it.

finally it is a good idea to check the wiring loom for damage or corroded connectors by tracing along the loom and visually checking everything.

Hopefully by this point you should have pinpointed where your problem lies (I hope

)

Thanks for reading, let me know what you think, or if there is any other info I should put in.

Fog

Foghorn Leghorn · Post by **Foghorn Leghorn** » Sat Sep 09, 2006 9:10 pm

Damnitt!!

Can anyone tell me why my links arent displaying correctly?

Fog

michaeljclark · Post by **michaeljclark** » Sat Sep 09, 2006 10:13 pm

The piccies aren't working becuase (I think) they're inserted as using the URL command rather than IMG command if you see what I mean

I've just inserted the first pic to prove the links do work using img!!!

Cheers

Mike

Foghorn Leghorn · Post by **Foghorn Leghorn** » Sat Sep 09, 2006 11:03 pm

cheers Mike

Not sure why I didnt see the img tags first time round, doh!!!

Fog

michaeljclark · Post by **michaeljclark** » Sun Sep 10, 2006 9:52 am

No worries

Post by **Welly** » Tue Sep 12, 2006 2:56 pm

Sorry Foggy, I meant to reply earlier........Great Post there matey, well done for putting in so much effort....

I have hereby rewarded you some Euro' points on here (redemption value 0.00000001 p each)

Foghorn Leghorn · Post by **Foghorn Leghorn** » Tue Sep 12, 2006 8:54 pm

Welton wrote:Sorry Foggy, I meant to reply earlier........Great Post there matey, well done for putting in so much effort....

I have hereby rewarded you some Euro' points on here (redemption value 0.00000001 p each)

Thank you kind sir

Will shortly be followed by a disc/pad and caliper change/overhaul, once I get round to ordering the discs. cant decide, either Brembo max or Black Diamond combis. Already got the pads, EBC green stuff. They're sat in my shed awaiting fitment. Will get them on order next week methinks.

Fog

Post by **Welly** » Tue May 01, 2007 2:42 pm

Well done, that's what this place is for

I'll know who to ask then if mine goes the same way because I am *crap* at electronics.

I've just ''blown up'' my second multimeter thing by using the wrong setting on it around the house

mjb · Post by **mjb** » Tue May 01, 2007 6:20 pm

All the images are 404'ing for me

jameslxdt · Post by **jameslxdt** » Tue May 01, 2007 7:47 pm

Welton wrote: I've just ''blown up'' my second multimeter thing by using the wrong setting on it around the house

let me guess, trying to measure current using the amp setting, when your actually measuring volts

Welton, havent you thought about buying a decent multimeter with built in surge protection and fuse protection

ive got a draper proffesional (snap on ones are overpriced and crap) one its lasted me a year and i really abuse it, it retails £99 but i got it for £63, trade discount

Post by **Welly** » Wed May 02, 2007 7:43 am

jameslxdt wrote:
Welton wrote: I've just ''blown up'' my second multimeter thing by using the wrong setting on it around the house
let me guess, trying to measure current using the amp setting, when your actually measuring volts

Welton, havent you thought about buying a decent multimeter with built in surge protection and fuse protection

ive got a draper proffesional (snap on ones are overpriced and crap) one its lasted me a year and i really abuse it, it retails £99 but i got it for £63, trade discount

How did you know that

I had a *really* crappy meter (the yellow cheap one) and it was giving a funny reading so in my haste I turned the setting through the voltage bit onto the amps bit and *poof* it was dead

I am good at 240V house electrics and can easily do ring mains and two-way lighting switching etc and I use the meter for conformatory checks when I isolate a circuit or whatever. But testing components and amps/resistance etc I cannot do.

Harshan · Post by **Harshan** » Mon May 28, 2007 11:01 am

Wow thats a great piece of information.. Mine is a D8 and i played plenty of time with the relay box between two fans and only those 3 relays I found has a direct link to the 2 fans. the green relay has a bi-pass line which passes the current in the off position and the bottom relay is the one which turns both fans at lower speed. When the green (the one in your right hand side) on turns on it cuts off current to the bottom one and provide a direct current to the right hand side fan and the other relay does the same to the left hand side fan. so both gets 12v each 'n start working in the full speed where as earlier it got 12 v for both the fans so both work in a serial manner and the 12 v get distributed among 2 fans so the speed is low.. (that explains why fans comes at lower speed at first)

now my question is .. does D8 has fan resistors.. where can I find them..

puggy · Post by **puggy** » Mon May 28, 2007 4:14 pm

And my question is... on a D9 is the fan supposed to come on at slow speed as soon
as you switch on the A/C or do what mine is doing just cutting in now and then at full blast....

jameslxdt · Post by **jameslxdt** » Mon May 28, 2007 4:18 pm

the fans should come on as soon as you turn on the a/c

puggy · Post by **puggy** » Mon May 28, 2007 4:25 pm

Thanks James... it doesn't so guess its a resistor or relay then....

take i that that is why its
not quite as cold as it should be either ...