radiator fan voltage?

[Grun]

clartsonly,

I am not looking at the vehicle itself, but the schematic circuit, which is very simple. From battery positive, through the fuse, via the thermo switch through the fan motor brushes and windings to earth on the chassis and thus to battery negative completing the circuit.

If the connector on the fan has two pins, the one with the red/black cable is the positive and the negative side (which goes to earth), will be the brown wire. It is shown as going to Earth point no 10 'Next to relay plate', which I assume is the star shaped cluster that other good folk often mention to check when things electricky play up.

The diagram shows three inline connectors in the circuit any of which could be dodgy, and all this assumes that the wiring is as original and that Haynes diagram is a fair representation.

A good earth is clean metal, no paint, no rust, that is part of the chassis/bodyshell and connected to battery negative, however distant that may be.

Wire size shown in Haynes is 2.5 mm square.

I am 70 years old and my eyes are not what they were, by the way.

[kevtherev]

clartsonly,

I am not looking at the vehicle itself, but the schematic circuit, which is very simple. From battery positive, through the fuse, via the thermo switch through the fan motor brushes and windings to earth on the chassis and thus to battery negative completing the circuit.

If the connector on the fan has two pins, the one with the red/black cable is the positive and the negative side (which goes to earth), will be the brown wire. It is shown as going to Earth point no 10 'Next to relay plate', which I assume is the star shaped cluster that other good folk often mention to check when things electricky play up.

The diagram shows three inline connectors in the circuit any of which could be dodgy, and all this assumes that the wiring is as original and that Haynes diagram is a fair representation.

A good earth is clean metal, no paint, no rust, that is part of the chassis/bodyshell and connected to battery negative, however distant that may be.

Wire size shown in Haynes is 2.5 square mm.

I am 70 years old and my eyes are not what they were, by the way.

well said grun good post

[Grun]

Oh I forgot, don't try using the multimeter on amps as it has virtually no resistance in that mode and is fused at about 1/4 amp using the normal lead sockets, and is normally about 10 amp but un-fused using the additional socket provided. So a blown fuse or a melted meter may result, if not used with caution.

You'll get there.

Mike

[clartsonly]

thanks for all your help, I have just got my multimeter delivered yesterday and it does have the 10 amp (unfused) socket - but I thought that was a bit low.

If I understand correctly just because I get 12 volts that doesn't mean there is enough current to spin the fan, so it is possible that one of these three inline connectors maybe a bit loose but is still completing the circuit. I have seen the star cluster behind the fuse box, I will see if I can pick my way through the wires and work out what is what. ( should be a fun job red/brown/green, orange/red, blue/purple all look the same to me

I still need some help in whether or not I could simply put two wires into the back of the fan and join it straight to the battery terminals and see if it spins? because if it is supposed to but doesn't - I know that the fan is faulty and can concentrate on removing the rad and fan.

[Grun]

clartsonly,

You could check the fan direct from a battery, but it would seem to be difficult to make safe connections at the fan, unless you have a spare two pin plug and you should use a fuse.

You could try to read the fan motor resistance with the meter set on Ohms, try 200 range to start, one probe on each pin. If open circuit meter reads 1 . You should expect some sort of reading if there is continuity, and of course if you you will get a low reading if you short the leads together while trying this.....quite likely.

I have only ever heard my fan running twice, both times in hot weather in the south of France with the engine idling for a long time in a traffic crawl.
Mike

[Mocki]

you can use the correct size spade connectors into the fan half of the plug, after you have disconnected the van half of the plug from it.....

you really need to establish if the fan works .

you also need to understand that the readings you get with a multimeter will be drasticly effected if you are testing underload, as oposed to unconnected wires, ie 12v at the fan connection may only be 3v when the fan is connected to it.

[clartsonly]

I have been discussing this situation with someone at work, where he has explained that resistance in the wires near the fuse or even on the connectors of the fuse if they are corroded, now at the begining of this thread I mentioned only getting 2 volts, since test the fuse voltage by forcing solder into each pin part where the fuse goes and removing the fuse box to check for any thing odd with the mess of wires behind it I started to get 12 volts.

I will try and clean up the fuse box connectors and maybe even try a different fuse and have a look and see.

I have only ever heard my fan running twice, both times in hot weather in the south of France with the engine idling for a long time in a traffic crawl.

I hear what you are saying, but I am constantly getting water coming out of the expansion tank, even after bleeding the system changing caps and water level seals. although when I was bleeding the system I really did notice that even though the bleed valve was fully open I seemed to have hot water in the expansion tank and cold water in the radiator, if someone thinks that the problem is more likely to be the thermostat or something like this instead I am all ears. I am sure the water pump is fine, as when I completely removed the bleed screw I shot coolant all over the drive at fast idle.

What would the situation be if the bleed valve was left open?

[Grun]

Try the Mocki method of bleeding, only criticism I have is... not enough coffee breaks, and they are too short.
https://club8090.co.uk/wiki/Co ... ing_system

[airhead]

Try the Mocki method of bleeding, only criticism I have is... not enough coffee breaks, and they are too short.

Ive only heard my rad fan run once, and I do drive a lot in heavy traffic. It came on when I was driving up the Sally gap in Wicklow (south of Dublin) on a warm day at high enough revs. When I pulled over (and I let the turbo cool by leaving the engine running for a minute or so) it stayed running for a couple of minutes after I turned the engine off and locked up the van.

[clartsonly]

right then,

today I tested the voltage at the fan 0.3v, checked the fuse tracked the wires backto the inside and noticed a load of white residue all over the earth crown, low and behold moved the earth terminal to the other crown and fan spins thanks for all your help.. I have attempted to clean up the other spade connectors on the crown too. I am so happy I finally can put the spare wheel back on and replace the grills and make it look normal again.

tried to retime it and bleed the water (again) it still cuts out when starting from cold but all I used to do was start it let it run for five or ten minutes then switch it off then return to it when we go on holiday. starter motor still needs replacing as it doesn't like hot starting at all still even though I changed the bush already.

thanks again I can cross something else off my list

[edoh]

good geezer

dont want to add to your list - but might be useful (when you av the time n inclination) - to spend a morning with the crown of earths - take out the screw that holds the crown to the body - and and clean up all the connectors including the one that goes into the body - with a green scourer - and make sure all the earth connections going to the crown are really clean n tight - a spalsh of wd - n your done -

good luck w the starter motor -