My fan only works at the first and second level but if you turn the gauge to 3 it shuts off completly and no air comes. Any ideas?

Thanks

/Nisse

Not had this problem yet, however as I understand it the 3rd speed works on a different fuse, so check that and the relay as it is only the 3rd setting that is affected.
Pete

Okay i'll check the fuse for the max level for the fan. Is it the fan relay that are next to the fuse box?

Thanks

The fan works as follows

The first and second settings run through a resisitor located in the heater box under the bonnet. On the pre-1984 cars this is a very easy component to get to. It is a bit tougher on the later 340s....

There is an auto-shut off system in the heater that disables the fan completely if the resistor gets too hot... so normally on hot days the heaters stops working on level 1 and 2..... but it will run on 3 as this doesnt use the resistor...

as for level 3 only but not 1 or 2... thats interesting.... and I think it is a extra fuse...

keep us posted what you find out... be interesting to see the solution

Shimon

Aha didn't know that, but it was intresting. It was so dark tonight so i could see if any fuses had blown. I'll have to check that out tomorrow. And it's strange because it runs at 1 and 2 but at 3 it shuts of completly.
I looked in the instructionbook and it is like you say a fuse for the fan 1 and 2 and the 3'rd set on the fan goes seperatly through a 16A fuse toghether with the brakelights and radio.

/Nisse

Hmm looks like the fuse hasn't blown afterall. Maybe there's a relay failure?

Ok little update
I were down at the local carstore and bought this haynes service manual (fantastic book btw) and it shows that first level of fan switch goes through 2 resistors, level 2 on switch goes through 1 resistor and level 3 goes directly through a relay. So i'm gonna locate this relay if there is one and see if it works.
Will be back with update in a while

What i can undestand is that the relay for the fan's third level is under the dashboard and it's quite complicated to get there so i'll save that job for a later time, its not critical

your last post reminded me of something

on one of my 340s, at some point a relay was removed from under the steering column in the area where there footwell soft cover goes. in this area is where the realy is located... I remember that once this realy was removed the fan didnt work on the 3rd level..... I dunno why I didnt remember this before

i remember that the I kept telling mysefl I have to refit that relay butI never did, in fact the realy is still in the drivers door pocket to this day... the car is in storage....

so, presuming the wiring in the left hand drive cars is a mirror that of the right hand drive... this means the relay should be in the area of the footwell above the drivers feet and under the steering column. there are a few relays round here but hopefully you can find the right one.....


sorry i didnt think of this before!!!!
good luck

summary of this post..... basically the 3rd level relay is near the steering column area of the footwell above the drivers feet..

good luck

Aha sounds very intresting! Sorry i've havent posted for a while, been busy. I finally got on my extra lights now also

I should take a look at this as soon as possible. Thanks!

Shimon is right about that resistor in drivers footwell. If I remember right , pull down the soft panel underneath the dash . There is a multiplug connector quite high up on the left side behind steering column this failed on mine and one of the results was the 3 setting on fan didnt work. If you give the connector a little wiggle it may work. Mine is fine now, just ceaned it up with emery paper . Good luck

Ok, i deleted the textile boarder under the steering wheel and there was a few relays but with little help from Haynes service book i could find the right colors of the wires that went to the fan relay. I took it off and one of the connector had got very rusted and corroded. Measuring with an ohm meter showed that there was shortcircuit between 85 and 86 (the pulling inductor) so everything points at the relay is broken. I'll buy a new one as soon as possible and hope it will do the trick But before buying a new relay i could also check with a volt meter that i get voltage on the wire from the switch that shall pull the relay.

Thanks for all help!

/Nisse

EDIT: wow you should see the old relay, shall see if i can get a pic of it...Ok fan works perfectly when force driving it. Just need to buy a new relay..

Ok here's the pictures. No wonder this didn't work....

I laugh - they do look beautiful!