Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Elite Pete on 23 May 2007, 15:46:35
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I got a call off the wife on Tuesday night saying the Omegas battery is dead (which is strange because its new) so I told her how to use the jump leads over the phone. What I noticed was the aircon fans came on without the ignition being on as soon as she connected the leads. I was wondering if I have done something wrong when I took the radiator out to flush it a couple of weeks ago. So where do I go from here.
Thanks in advance :y
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Hi Pete,
If it's just appeared but was fine since the rad. change I would think the most likely cause is that one of the relays driving the air con fans has stuck in the "on" position.
A temporary fix would be to remove the offending relay from the engine bay relay box. There's a diagram showing which one's which in the engine bay fuse box here: http://www.omegaowners.com/forum/YaBB.pl?num=1176560725.
Any of those relays which are marked as aircon only would be a good start. Just pull them out one at a time until you find the one that stops the fans then let us know which one it was.
I'll have a closer look at the wiring diagrams tonight and see if anything else occurs to me.
If you get desperate, just unplug the fan motors for now.
Cheers,
Kevin
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Cheers Kevin :y
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Pull the two 20A fuses, easier to take out than the relays....
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Or the rad switch has gone short circuit....
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Is it the auxiliary fans in front of the rad. or the engine fan behind the rad?
Are they running at full speed or half speed and are both running or just one?
Cheers,
Kevin
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Is it the auxiliary fans in front of the rad. or the engine fan behind the rad?
Are they running at full speed or half speed and are both running or just one?
Cheers,
Kevin
Hi Kevin
Its the auxiliary fans in front of the rad, both are running and at full speed, my wife was on the phone as I was explaining which jump lead goes where and as soon as she connected the negative I could hear the fans and I was in Slough ;D
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Just had a thought, I pressure washed the condenser from inside the engine bay out and also the radiator but that was over 2 weeks ago, could it be water is in one of the switches and is causing a short. Are the switches on the right hand side of the rad looking from the front of the car?
TIA
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Just had a thought, I pressure washed the condenser from inside the engine bay out and also the radiator but that was over 2 weeks ago, could it be water is in one of the switches and is causing a short. Are the switches on the right hand side of the rad looking from the front of the car?
TIA
Yep.
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Had a quick look at the wiring diagrams and there is a relay that drives the fans at slow speed when the air con is on. However, if they're both running at high speed my money's on one of the thermal switches on the radiator or there's an outside chance that it could be the pressure switch in the air con circuit.
Kevin
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I'm fairly certain that the 'high speed' fans are connected to ign feed, low speed fans to permenent....
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I'm fairly certain that the 'high speed' fans are connected to ign feed, low speed fans to permenent....
Could be. There were certainly two fused feeds to the fan circuit and both looked permanent from the quick glance I gave it last night. Certainly a single relay failure will cause them to run at low speed indefinately. for them both to run at high speed we're talking about multiple relay failures or a single switch, but only if the feed is permanently live. If it's not then back to the drawing board.
I didn't realise you were working remotely, Pete. Has she at least got it temporarily sorted?
Cheers,
Kevin
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I'm fairly certain that the 'high speed' fans are connected to ign feed, low speed fans to permenent....
Could be. There were certainly two fused feeds to the fan circuit and both looked permanent from the quick glance I gave it last night. Certainly a single relay failure will cause them to run at low speed indefinately. for them both to run at high speed we're talking about multiple relay failures or a single switch, but only if the feed is permanently live. If it's not then back to the drawing board.
I didn't realise you were working remotely, Pete. Has she at least got it temporarily sorted?
Cheers,
Kevin
Im back home now Kevin and will have a look tomorrow but I havent got a clue where im going with this. So am I right in thinking that with the fans running at full speed its not going to be a relay and more likely to be wiring :'(
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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
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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?
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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 :y
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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 :y
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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
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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....
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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
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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)
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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 ;D
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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.
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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
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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.
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@rse... <scratches head>. I'll have to look at the wiring diagram again!
Kevin
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When removing the relays I noticed relay No 3 is very hot
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That's interesting. They shouldn't get hot.
Kevin
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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.
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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
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Ive taken the battery off to give it a charge but will try in the morning.
Thanks for all the help Kevin :y
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OK. I've had another look and relay 3 on that diagram is the auxiliary water pump. I can't see why it would get hot except that its' coil is energised whenever the ignition is on, so if the ignition had been on for a while I guess it may have got warm.
Also, I didn't realise that not all of the fan relays are in the engine bay box. I suspect relay K28 is the problem but I don't know where to find it!
It should be an orange one similar to no. 19 in the engine bay box as far as I can see.
Cheers,
Kevin
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Thanks Kevin
What I need now is someone who has stripped an Omega to tell me where the other relays are.
Anyone :)
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Thanks Kevin
What I need now is someone who has stripped an Omega to tell me where the other relays are.
Anyone :)
What I need to know is...should I bother with the coolant flush I had planned? cos this sounds like hard work Pete and I'm as clueless as you. Anyway, best of luck matey :y
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What I need now is someone who has stripped an Omega to tell me where the other relays are.
They can't be that far away. The fuse that feeds them is in the engine bay relay box, the fan they feed is by the radiator. I can't believe they'll have hidden them far from the radiator, although stranger things have happened.
Kevin
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I think you may find K28 may also be a K52 according to year/model.
regards,
richard