the radiator fan has flattened my battery

Website · Post by **dbroada** » 25 May 2006, 18:01

I haven't used the van for a couple of weeks but I was still surprised to fibd it not even wanting to turn over this morning. Even more surprising was only 8 volts when I checked this morning. A quick check revealed a 3 Amp load. I finally tracked this down to the radiator fan runnung!!

I know at 8 volts I've probably lost the battery but I'm charging it just in case.

What I don't know is why the fan is running. Are there any usual suspects to check? Obviously in this drought there is a chance of soaked connections but any ideas where I should start looking?

many thanks,

Post by **trickydicky** » 25 May 2006, 18:20

I have spent the last week being very close with my radiator (air lock dodgy thermostats etc

)are you sure it is the rad fan as when mine cuts in it sounds like a plane

If it is I can't see how water ingress could be an issue, you might want to try disconneting the wire from the switch in the rad and if your fan keeps spinning it will show if the switch is the problem, good luck

Website · Post by **dbroada** » 25 May 2006, 19:09

I agree it doesn't sound like the fan usually does but at 6v its not going to spin very quickly. 2 of us have listened and both agree its coming from behind the grill - its definitely not the interior fan.

Having now looked through the circuit diagram I currently thinking the fan relay is the culprit. Which if my memory serves me right (for a change?) is where the water runs down from the leaky screen. Just going out to check while there is still some daylight.

Post by **Hacksawbob** » 25 May 2006, 19:18

faulty fan thermostat? somewhere up by the rad

Website · Post by **dbroada** » 25 May 2006, 19:43

could be.

Having looked for the relay I don't think I have one. (Early 5 way fuse box). Actually, I have 1 relay and that's in position 3 (X-contact). I don't even have a flasher unit but I do have some wires running from its position.

Looks like I'll be investigating tomorrow.

Post by **trickydicky** » 25 May 2006, 19:54

To get to the switch remove the grille and it's on the right hand side

Website · Post by **dbroada** » 25 May 2006, 19:55

thanks. does water come out when you do that?

Post by **trickydicky** » 25 May 2006, 20:14

Not if you just take of the electrical connector but if you remove the switch Oh yeagh, Happy bleeding

The sensor is quite a big socket mind. bigger than I had.
Should only be in the rad though, make sure the cap is on an as a fail safe put a clamp on the overflow hose and raise the front.
Have a look at the Italian Job in general chat to see how I did it

Website · Post by **dbroada** » 25 May 2006, 20:51

that's not far off the angle I park at anyway.

I'll have a look at the conections tomorrow. Could well be rewiring the fuse as a temp solution - and we all know how long temp fixes last.

Post by **Hacksawbob** » 25 May 2006, 21:00

and we all know how long temp fixes last.

indefinately!

Post by **trickydicky** » 25 May 2006, 21:14

I reckon that if you disconect the switch (sensor) and the fan stops running then get yourself a new switch (G.S.F. part No. 251-959-481K £7.95 + V.A.T.) and see if that does the job.
Ideally you would go to an auto electician and get them to trace the source but with minimun charges and generally high hourly rates it's got to be worth a pop.

Website · Post by **dbroada** » 26 May 2006, 20:31

well it looks like the battery might hold a charge still - certainly hope so, we're off camping next weekendd.

But the current drain will for now remain a mystery. When I got in from work this evening I rechecked the current drain. For a moment it was the 3,5Amps of last night then fell away to 0,05A - and no fan noise. I have just rechecked and still the 0,05A (which is probably the radio) and still no fan noise.

I'm now thinking the radiator sensor had tracked out in the rain and has now dried. Oh how I love intermittant problems! At least it lasted long enough to diagnose WHY the battery was flat.

Post by **TechtroT25** » 26 May 2006, 20:45

Gotta change me rad fan sensor this weekend dreading it now cos i hate having to bleed these things you always wonder have i got the last of the air out just waiting for the thing to chuck all its coolant out of the headgaskets