Aux Coolant pump AGAIN!!!!

[Timo. 0]

Finally got around to getting a new one from the dealers yesturday and this morning I though i'll just check to see it work without plumbing it in. (I know it a magnetic thingy and probably wont do much with being properly connected into the coolant system) But anyway I gave it a shot. Turned on the ignition and nothing...... Mmmmm..... bugger....whats up now!!!

 

When I realised the old one wasn't working I did the obvious and checked the power. Sure enough it was getting a healthy 12v and thought 'great' its definitely the pump. Today when I checked the power after the new pump failed to show any sign of life, I get no power reading!! :cry: :cry: Gutted. Not sure whats happen.

 

Can it have blown a fuse or something. There's nothing else that dont work. I have tested the positve and -ve lead to see which one isn't doing the business. The -ve seems fine but cant get any reading from the +ve so I'm guessing there is a break in that wire somewhere.

 

Help me please!!1 Rather pi$$ed off now

 

cheers

 

timo

[Timo. 0]

Come on guys..... someone must be able to help me.

 

Another thing I tried was to bridge some of the connections on the yellow temp sensor (as it says in bentley) to test the coolant run-on module. The fan came on and 12volts was readable from the aux coolant pump connector!! Weird!!! :roll:

 

Really confused now. Gonna change the pump anyway tomorrow and then worry about the power issue.

 

ta

 

timo

[dr_mat 0]

There's two separate circuits - the run-on circuit will probably trip the same relay as the ignition-on circuit, but it'll source it's signal from a different point in the system.

Hence the run-on works as expected, but the ignition-on doesn't. Sadly I don't really know any more than you about where to start looking for problems with the ignition-on circuit, but it'd be a good place to start by going through all the fuses in the box and making sure they're all ok.

[Timo. 0]

checked all the fuses. Might try disconnecting the battery to reset the ECU. Not done it in a while anyway and its worth a shot. I just dont understand how it had power a few weeks ago and now it doesn't. Bloody annoying if nothing else.

 

But, at least the run-on circuit does work which I think is definitely more important. I always thought that the aux pump running whilst the engine was started seemed a bit wasteful and pointless. There could be something I'm missing of course!! :roll:

 

cheers

 

timo

[Timo. 0]

Bump, Right the story so far. Aux Coolant pump doesn't run when the ignition is on or when the engine is running. Which it should. It does however work when the car gets to hot and the fans kick in. Or, when you test the fan run-on circuit by bridging two connections on the the yellow thermostat temp plug.

 

What the smeg is wrong with it? Not really hugely concerned with the fact that it dont work. Seems to me it is almost wasteful/pointless having to water pumps going at the same time. It just frustrating. There's obviously a fault/problem somewhere. Maybe there's a dirty connection somewhere, perhaps at the ECU because I've checked everthing else.

 

Any help?

 

Timo.

[bigpants baby 0]

are you getting power from the black and white wire from the fan relay(by the header tank,big clunky plastic box with a couple fuses in there)?

[Timo. 0]

Couldn't get any voltage reading from the black and white wire with the ignition on. I take it, it's the thin black/white wire coming out of the bottom of the box with the smaller connection plug. There aint another black/white wire so I dont think i could have tested the wrong one.

 

What does that mean then? Something wrong with the relay?

 

Ta

 

Timo.

[Timo. 0]

bigpants baby, Any more help would be appreciated mate 8)

[bigpants baby 0]

which wires have got 12v when ign on and off

[Timo. 0]

Emm, need to check it out the morn. Really rather frustrating. I'll try testing them all for voltage. Might have a look at the electrial diagram in ma bentley manual to see if that'll help.

 

cheers

 

Timo.