Cooling fan question
Discussion
OK, this not just an excuse to bump my question.... but some more questions!
The reason I asked the first question was that one of the fans seemed to be coming on (the offside fan) at about 98 degrees (according to the dash)and I was wondering whether the lower temp fan was not working, or that there was the usual discrepancy between ecu and pod sensors and it was the lower temp fan that was coming on after all.
So, just disconnected the ecu water temp sensor expecting both to come on...and neither has come on
. Fuses are OK, and one fan did come on last time I was running at temp. There is 0.5V across the ecu sensor connector.
So, questions are:
If I disconnect the ecu sensor to get both fans on, do I need to have the engine running rather than just the ignition on?
If not, what the
is going on??
The reason I asked the first question was that one of the fans seemed to be coming on (the offside fan) at about 98 degrees (according to the dash)and I was wondering whether the lower temp fan was not working, or that there was the usual discrepancy between ecu and pod sensors and it was the lower temp fan that was coming on after all.
So, just disconnected the ecu water temp sensor expecting both to come on...and neither has come on
. Fuses are OK, and one fan did come on last time I was running at temp. There is 0.5V across the ecu sensor connector.So, questions are:
If I disconnect the ecu sensor to get both fans on, do I need to have the engine running rather than just the ignition on?
If not, what the
is going on??Not a T350 but on a Tuscan normally the off side fan comes on at 92 DegC and the nearside at 96 Deg.C.
The engine does need to run to put the fans on. If you have a laptop/cable & software for the MBE ECU you can see the fan on signals and the temperature from the sender that controls them.There are two senders one to control the fans below TB5 and one to the front of the engine for the display temperature the two can differ by up to 5 DegC.
I have found the relays can be a weak point as the contact rating is a bit boarder line, I have up-rated ones on mine now, could be worth swopping them over to check. Also the fan connector are quiet vulnerable to water and corrosion so would be worth checking these as well.
The engine does need to run to put the fans on. If you have a laptop/cable & software for the MBE ECU you can see the fan on signals and the temperature from the sender that controls them.There are two senders one to control the fans below TB5 and one to the front of the engine for the display temperature the two can differ by up to 5 DegC.
I have found the relays can be a weak point as the contact rating is a bit boarder line, I have up-rated ones on mine now, could be worth swopping them over to check. Also the fan connector are quiet vulnerable to water and corrosion so would be worth checking these as well.
Pull the water temp sensor connector off and both fans should come on. The sensors and the reading will be all over the place.
When mine used to say the car was 98 we had it checked with specialist equipment and it was actually 89.
My engine now and before transplant with the S6 had to have the engine running to have the fans work - even with the ignition in position two after switch off the fans would not work. I had a different chip supplied by power which meant the fans came on earlier when I had the S6 in it.
Not sure if I have helped - I am pretty sure someone with way more knowledge will help.
When mine used to say the car was 98 we had it checked with specialist equipment and it was actually 89.
My engine now and before transplant with the S6 had to have the engine running to have the fans work - even with the ignition in position two after switch off the fans would not work. I had a different chip supplied by power which meant the fans came on earlier when I had the S6 in it.
Not sure if I have helped - I am pretty sure someone with way more knowledge will help.
Thank you both for the advice - very useful! I have an ECU cable on order so will hopefully have that connected at the weekend to check the sensor temps.
In the meantime, I guess I'll just fire it up without the cable connected to the ecu temp sensor and see if they both come on, and have a mess around with the relays.... actually, better not annoy the neighbours so will have to wait
Thanks again
In the meantime, I guess I'll just fire it up without the cable connected to the ecu temp sensor and see if they both come on, and have a mess around with the relays.... actually, better not annoy the neighbours so will have to wait
Thanks again
Just to complete this one for any future use.... You probably know all this anyway, but I couldn't find it in a search.
On my T350, just like the Tuscan above, the offside fan comes on first, at 91.5C according to the ECU(couldn't get it hot rnough to swich on Fan 2)
Also as above, if you pull the plug on the ECU water temp sensor, you have to have the engine running for both the fans to come on. They won't come on even if the ignition is at position 2.
Other stuff I've discovered today -
As with other peoples, the temperature reading difference between my dashboard and ECU water temp sensors is about 8 deg C below 70 deg C, and about 5 deg C when in the 90's
The immobiliser has to be off to get the ECU to read out data to the diagnostic software
Serial port to USB converters are rubbish
and running a TVR up to temp makes for a much warmer garage...
As I say, probably all old news, but hopefully may help with searching for someone else.
On my T350, just like the Tuscan above, the offside fan comes on first, at 91.5C according to the ECU(couldn't get it hot rnough to swich on Fan 2)
Also as above, if you pull the plug on the ECU water temp sensor, you have to have the engine running for both the fans to come on. They won't come on even if the ignition is at position 2.
Other stuff I've discovered today -
As with other peoples, the temperature reading difference between my dashboard and ECU water temp sensors is about 8 deg C below 70 deg C, and about 5 deg C when in the 90's
The immobiliser has to be off to get the ECU to read out data to the diagnostic software
Serial port to USB converters are rubbish
and running a TVR up to temp makes for a much warmer garage...
As I say, probably all old news, but hopefully may help with searching for someone else.
Yep thanks for the reminder Clive - got so engrossed in the diagnostic software now I've got my lead, I forgot to do anything with these! They are both very exposed, and I can't decide whether to seal them up with tape or heat shrink, or leave them open to the air, so if water does get in, it dries fairly quickly rather than having it seep in and then not dry.
Can you not come up with a high quality, self-drying, good looking electrical connector to match that expansion tank you've just done?
Can you not come up with a high quality, self-drying, good looking electrical connector to match that expansion tank you've just done?
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