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[Elite Pete]

Hi Pete,

Let me have another look over the diagrams tonight and come up with a plan of attack. There was one set of relay contacts which would certainly cause them to run at slow speed in the event of failure. Both fans at high speed requires 2 relays to change over so unlikely unless a thermo switch is driving them - hence themo switch more likely in this case. If Theboy is correct and the high speed side is driven from an ignition switched feed that's even less likely.

Have a look tomorrow at what's running and what's not and I'll try and put together some things to try to narrow it down.

Kevin

Thanks Kevin

[Elite Pete]

it may be the feed to operate the high speed fan coils relies on ign 12v, rather than the direct power feed to relay contacts - would need to check.

EP - is it both fans, or just 1?

I will use the jump leads and have a look but I think its both when the wifie gets back with the diseasal.

She's gone shopping so it could be late

Thanks TB

[Dave-C]

I'm fairly certain that the 'high speed' fans are connected to ign feed, low speed fans to permenent....

Pete,
If this is the case, could also be a possible damaged wire going to earth!!!  Causing the fans to run....

DC

[TheBoy]

I'm fairly certain that the 'high speed' fans are connected to ign feed, low speed fans to permenent....

Pete,
If this is the case, could also be a possible damaged wire going to earth!!!  Causing the fans to run....

DC

sorry, i meant the relay contacts are still on +ve side, but then off to permenent....

[Kevin Wood]

I've had another look at the wiring. I'd hazard a guess that the guy who designed this used to design telephone exchanges. Relays everywhere!

Some of the relay coil feeds come from an ignition switched source but not all. The fan feeds are straight from the battery via fuses. The components that could cause fans to run continuously are as follows AFAICS:

K87 - Aux fan relay - Aux. fans would run on slow speed
S88 - Cooling fan switch - Aux fans and rad. fan running slow.
S20 - Air conditioning refrigerant pressure switch - Would only leave a relay coil powered but may drain battery eventually

As far as I can see all the fast running options would requre ignition switched power or a multiple relay failure.

I'd start by pulling K87 and then S88, which is the rad. thermostatic switch under the top rad. hose, and see if either of them stops the fans.

Kevin

[TheBoy]

I've had another look at the wiring. I'd hazard a guess that the guy who designed this used to design telephone exchanges. Relays everywhere!

Some of the relay coil feeds come from an ignition switched source but not all. The fan feeds are straight from the battery via fuses. The components that could cause fans to run continuously are as follows AFAICS:

K87 - Aux fan relay - Aux. fans would run on slow speed
S88 - Cooling fan switch - Aux fans and rad. fan running slow.
S20 - Air conditioning refrigerant pressure switch - Would only leave a relay coil powered but may drain battery eventually

As far as I can see all the fast running options would requre ignition switched power or a multiple relay failure.

I'd start by pulling K87 and then S88, which is the rad. thermostatic switch under the top rad. hose, and see if either of them stops the fans.

Kevin

That is my understanding from memory (both the tractor, and Project TB1 last summer)

[Elite Pete]

I've had another look at the wiring. I'd hazard a guess that the guy who designed this used to design telephone exchanges. Relays everywhere!

Some of the relay coil feeds come from an ignition switched source but not all. The fan feeds are straight from the battery via fuses. The components that could cause fans to run continuously are as follows AFAICS:

K87 - Aux fan relay - Aux. fans would run on slow speed
S88 - Cooling fan switch - Aux fans and rad. fan running slow.
S20 - Air conditioning refrigerant pressure switch - Would only leave a relay coil powered but may drain battery eventually

As far as I can see all the fast running options would requre ignition switched power or a multiple relay failure.

I'd start by pulling K87 and then S88, which is the rad. thermostatic switch under the top rad. hose, and see if either of them stops the fans.

Kevin

Thanks Kevin I will have a go tomorrow.

I was thinking along the lines of the switches on the rad as these are the only things that have been disturbed in the last couple of weeks (apart from me) and the Fernox I put in the rad to clean it is strong stuff and I got it everywhere, the wife is still moaning at the large dead patch of grass

[Elite Pete]

I have taken the grill off this morning and there is only the drivers side fan running. I have disconected the switch at the top of the rad and the fan is still running. So it would point to a relay but is it the same relays as previously mentioned.

Sorry to be a PITA.

[Kevin Wood]

No problem, Pete.

Most likely cause is a relay if it's just the one fan running. Haven't got my diagrams in front of me but I'd say open the relay housing with reference to this post http://www.omegaowners.com/forum/YaBB.pl?num=1176560725 and try pulling out the relays numbered 3,4,5,6 & 7 one at a time and note which one(s) stop the fan running.

If you let me know what happens and I'll have a look later and see what the likely issue is.

Cheers,

Kevin

[Elite Pete]

Hi Kev

I've pulled the relays one by one and the fan is still running. The only way I have stopped the fan is by pulling the first 30 amp fuse 28A on the diagram.

[Kevin Wood]

@rse... <scratches head>. I'll have to look at the wiring diagram again!

Kevin

[Elite Pete]

When removing the relays I noticed relay No 3 is very hot

[Kevin Wood]

That's interesting. They shouldn't get hot.

Kevin

[Elite Pete]

The others are fine but No3 is hot to touch. I was thinking of going to the stealers to order one for the morning because you know they wont have one in stock.

[Kevin Wood]

I could understand it if the fan stopped when you removed no.3 relay. Does that relay cool down when you pull the fan's fuse out?

Kevin