Internal Fan / Heater Constantly on !

[avitohyes]

Hi all,

Bit of a weird one - got up on Sunday to a flat battery. Didn't know why - battery charged and all ok...until tonight! The internal heater / fan started of it own accord..no amount of turning dials could stop it....I even took the keys out and the fan stayed on ( This is the internal fan and not the radiator).

I managed to remove a fuse to isolate the fan, but would like to know if anybody has an iota of a clue what might be causing this...a sticky relay perhaps? Does anybody know what relay(s) is/ are associated with the internal fam/ air con ?

By the way, its an Vectra 06 1.8SRI !!

Any help would be appreciated

Thanks

[67688c]

Sounds like a stuck relay for the fan motor, and if so, its quite possible the contacts may have stuck or welded together holding the power on, just a thought. certainly worth checking out the easier/logical options such as this first. There are also different relays for the different fan speeds, I did post a circuit of the fan switch circuit, motor and relays several months ago for one of the members (copied from Haynes manual) because one of his fan speeds was not working or something similiar. His problem turned out to be a relay. Do a search for fan speed or similar you may be able to locate it, should you need it.
If you want me to scan it in and post again let me know.

[djr69uk]

Yup and it was me and it's still working fine a good few months later

Here is the thread:

http://www.vectra-c.com/forum/showthread.php?t=56294

From your symptoms it sounds like it could be relay K5 - that's if it is a relay fault. That's the one that sends current straight to the motor. If your internal fan motor is on full pelt (i.e. position 4 speed) then it is almost certainly this.

If it isn't that then something must have caused the relay to close - i.e a switch - which to me suggests it could be a fault or stuck switch with the control unit itself.

[67688c]

Yup and it was me and it's still working fine a good few months later

.

I remember thinking you showed some good diagnostic skills, and a better understanding of the circuit than me, and I was in the electronics business for many years..lol so yes you did well there matey.

I'm pleased to hear it's still working fine... nice one!

[djr69uk]

I remember thinking you showed some good diagnostic skills, and a better understanding of the circuit than me, and I was in the electronics business for many years..lol so yes you did well there matey.

I'm pleased to hear it's still working fine... nice one!

Eh... I'm just a lowly IT guy lol!
Seriously, I did appreciate your input on that one chap - saved me 300 squids!

[avitohyes]

Yup and it was me and it's still working fine a good few months later

Here is the thread:

http://www.vectra-c.com/forum/showthread.php?t=56294

From your symptoms it sounds like it could be relay K5 - that's if it is a relay fault. That's the one that sends current straight to the motor. If your internal fan motor is on full pelt (i.e. position 4 speed) then it is almost certainly this.

If it isn't that then something must have caused the relay to close - i.e a switch - which to me suggests it could be a fault or stuck switch with the control unit itself.

Hi thanks for the info. Once into the relevant area took K5 out, opened it up and had a look at the relay contacts and they looked too close for comfort. I've ordered what I hope will be an equivalent relay off Maplin website ( seems to have all the requirements) so we'll see. If it works I owe you a pint or two the next time your in Liverpool! ( ps don't hold the fact I'm a scouser against me - lol!!).. I'll let you know how I get on.

[rushy]

Have you pulled the switch panel, if you tug on the dial that controls where the heat/cold goes the whole panel pulls out. There are 2 plugs. I didn't connect mine properly when I converted the SMDs and the speeds all went to ****. I doubt it is the panel though as with the ignition off the panel is dead, worth a look though.

[avitohyes]

Aaah sadly the relay didn't work, though it is an intermittent fault. The fan comes on and I can stop it by hitting the glove box! can't see me doing that for the rest of my life lol - may have to delve a bit deeper at the weekend but any further suggestions would be much appreciated

[rushy]

The switch might work by earthing itself, so there might be a bare wire behind there somewhere.

[Kcs]

Just a thought, i had what sounded like the fan blower stuck on, but it turned out to be the internal fan on the cd70 nav ! ! dohh !