S2 ABY Over heating at idle

[B5NUT]

Has anyone got the the wiring diagrams for the ABY, I've search and cannot find anything. I'm not sure on the plug which is pin 1 & pin 3?

Also I think some has been removing fuses and may be a relay from the fuse box.

This is what I have at the moment.

Fuse 20 has been removed which is for Radiator fan 1st speed
Also Radiator fan relay has been removed

Should these both be present in my car, as it does have aircon (all be it broken at the moment due to the condenser failure)

fuses.jpg

fuse-cover.jpg

[newsh]

ABY doesn’t have fan delay.
Try moving your fan relay one space to the left.

[B5NUT]

OK so that has been put in the correct place I also noticed you have fuse 19 & 20 missing same as my car is that normal.

[newsh]

Yes, normal I believe

[B5NUT]

So I found the pin number on the plug they are on the top just difficult to see. Tested pin 2-3 and the fan comes on OK, also tested 1-3 and again the fan come on OK. So I've received a new temperature switch this morning, Will see if that fixes the issue.

[B5NUT]

Fitted a new temperature switch and it's still the same, no fan kicking in! The Aux rad is over 100 same as the block yet the the lower part of the main rad is around 90, so I just don't think it's getting hot enough to activate the switch. The Aux rad appears to be taking the brunt of the temperature, so that would indicate the flow is mainly heading towards the aux rad. So would that indicate a flow issue with the main radiator?

I also put jumper between pins 2-3 and then ran the engine. The fan kicked in and I could not get the temp above 90.

With the jumper in pins 2-3 does this sound like 1st fan speed just sounds a little high to me cluster8.website-staging.uk/myaudisite.co.uk/fan.mp4

I also tried with the A/C button switched on the light on the button comes on but the fan does not operate.

[steve briance]

Try testing the switch in a pan of water on the hob. I dont know what the switch signal is, whether its a simple on off continuity or a resistance value but, it should do something ifnits getting a hot water supply!

I also suppose it is possible the bottom of the rad has enough crud to 'bury' the fan switch. Ive never seen that much come out of mine but, for the sake of a few hours work, I would drain, flush rad through and refill... As you are chasing a fault which may need the system draining again if you dont get to the bottom of it, id keep the coolant unless it is really dirty. If the flush fixes it treat it to new pink stuff then!

At least the wiring seems to be in order - finding a loom break is not fun.

[Tractor Dave]

This thread has the excellent guides written by URS4BOY. Work your way methodically through each part and I'm sure you will get there. Another possibility is that the plastic impeller has broken down on the water pump. Without circulation, the hot water won t reach the bottom of the radiator.

https://www.s2forum.com/forum/technical/engine-and-turbo/75036-cooling-fan-testing

[B5NUT]

To be honest the more I look at the radiator the more It believe it's causing the problems. I've removed it again and removed the temp switch. There is plenty of brown sludge in there, and you can see it in the channels. I'm going to try and clean it out this evening/tomorrow and it's no better then I'll take it to a radiator specialist on Monday morning, if they cannot flush it out then I'll get a new rad on order.

I think the Aux rad is clear because it's higher up in the system, but at some point next years I'll also have to replace the heater matrix as I bet there is plenty of crud in there as well.

[SteveH]

If you go for a new rad don't get a Nissens metal jobbie, they leak pretty quick. Get a Berh/Hella item if you can.

[Monkeymagic]

Best set a day aside for the heater matrix.

[B5NUT]

I've done a few on the B5 A4, it's not a fun job. Will be waiting for a nice warm sunny day.

[Ian Simmonds]

I've done a few on the B5 A4, it's not a fun job. Will be waiting for a nice warm sunny day.

This S2 forum heater matrix tutorial might help…

https://www.s2forum.com/filedata/fetch?id=2005355

[Bowie69]

Allow a very full day, and you will find other bits to tinker with like heater cables, flaps and the like, re-wrapping wires too.... have some tesa tape handy...

[larsaskogstad]

B5NUT:
- Have you checked if it's circulation in the heater matrix? Is both hoses going into the heater matrix hot after a while? both in and out?
- In the pictures I've uploaded marked red , do these hoses get very hot?

Do this as first step , If not its:
a) not bled properly -or- water pump might be broken/semi-broken.