Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: BazaJT on 18 September 2019, 18:15:11
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Before I tear it all down again to try and sort this[basically by chucking yet more new parts at it]does anyone have an idea of which bit
might need changing? Start the car from cold and temp gauge gradually rises until it hits a registered 90 then drops slightly[obviously thermostat opening]before climbing slowly back up until it registers just over 90 at which point all three fans start up together.This drops the temp back to 90 but will not go lower and the fans won't shut off until after the engine is stopped.A new radiator was fitted last year along with new fan switches and also new coolant temperature sensor and temperature sender were fitted along with a new thermostat.Could one or more of these be faulty?if so is there anyway to tell which one other than by substitution?Could it be poor coolant flow caused by poor water pump performance?
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quote BazaJT
"Before I tear it all down again to try and sort this[basically by chucking yet more new parts at it]does anyone have an idea of which bit might need changing? Start the car from cold and temp gauge gradually rises until it hits a registered 90 then drops slightly[obviously thermostat opening]before climbing slowly back up until it registers just over 90 at which point all three fans start up together.This drops the temp back to 90 but will not go lower and the fans won't shut off until after the engine is stopped.A new radiator was fitted last year along with new fan switches and also new coolant temperature sensor and temperature sender were fitted along with a new thermostat.Could one or more of these be faulty?if so is there anyway to tell which one other than by substitution?Could it be poor coolant flow caused by poor water pump performance?"
one of the relays sticking shut :-\
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what model year ?
I'll look at the wiring diagram
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it's a year 2000 facelift 3L auto.I'm sure I've seen somewhere on here that two of the relays are interchangeable[one for the fans,can't recall what other relay is for]but I can't remember which two?At least this might test the relay theory.
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Have you established that the aircon was/not working :-\
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Aircon does not work and never has,however the fans did previously behave as they should-as in cutting in to cool things down and then shutting back down again without constantly running until after the engine was stopped.
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It could be an issue with the aircon relays which is affecting the cooling fans... :-\
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It could be an issue with the aircon relays which is affecting the cooling fans... :-\
astra g of that 2000 era put the fans on full if the ac pressure switch was disconnected,or the CTS
(can be tricked with a 4k7 potentiometer into thinking it has low pressure but has the sensor,fan control ok)
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Being the 3.0, Haynes will guide you through the wiring...
ECC (electronic climate control) diagram should do it :y
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Is there a simple way[car electrics are a black art to me]to check whether relays are working as they should or is it a matter of substitution?I found the other week that the aircon compressor bearing
were shot so as the system has never worked in my ownership I put a non-aircon auxiliary belt on,but this fan problem was occurring before the belt was changed. Just seen your latest post DG will have a look see what St.Haynes has to say :y
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Been to the lock up today started out by doing fan test.Results were ign. off FT1 and FT2 all three fans on slow speed FT4 and FT5 no reaction from any of the fans at all ??? Ign on all tests were as should be.Running the engine and once up to about 92 on the gauge all 3 fans start up at once dropping temp to an indicated 90 but won't go any lower and fans don't stop until after engine switched off.The aircon/climate doesn't work and the compressor which is shot is by-passed using the shorter belt,however the aircon doesn't work on my V70 either but the fan still cuts in and out as it should so I don't understand why the Omega wouldn't.
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It's down to how the fans are controlled. Aircon overrides normal fan operation, with the engine ecu having final say if things get too hot.
What you need to check is that the radiator switches are a) correct, and b) working. :y
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So are you saying one or both rad switches could be faulty as opposed to a relay? If that is the thinking then I'll get one or both switches[although the present ones were new when the rad was changed one/both could be faulty.
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Indeed as they power the relays ;)
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Ta muchly DG I'll see about getting two[to be on the safe side] new fan switches then.Any place better than others to get them from?
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Local factors should do the job :y