Engine Fan Relay

[jned2]

Looking to replace The Engine Fan Relay on my 1990 S3. Can't to find a part number or where they might be available. It's a 5 prong relay. Any help gratefully appreciated.

[phillpot]

"Standard" relay, yours may have 5 connections but for simple on/off like a fan you only need a 4 pin. Any half decent Motor Factor should have one or Ebay

https://www.ebay.co.uk/itm/221153538914?hash=item3...

5 pin if you want to change like for like

https://www.ebay.co.uk/itm/221233396126?hash=item3...

Edited by phillpot on Thursday 16th June 11:19

[TwinKam]

Just be aware that not even 'standard' relays have a 'standard' terminal layout, there's a Type 'A' and a Type 'B', so ensure that you've got the correct type, or amend the wiring to each terminal to suit.

[phillpot]

This is the layout of what I would refer to as a "standard" relay, 5 pin would have another connection in the middle. 87a

[TwinKam]

Both of these (and their 4 pin equivs.) are 'standard' relays... spot the difference.
Answers on a postcard please.

[jned2]

The relay I'm after is the same as in phillpot's picture but with an additional connector in the middle 87A; i.e. the same as TwinKam type B. I presume that if I follow phillpot's advice and go to any decent motor factor then I should be able to pick up what I'm after, or are they available elsewhere? Many thanks.

[jned2]

Quick update. In the product information for the 5 pin relay recommended by phillpot above it states that the terminal configuration is Type B, which is what I'm after. Once again many thanks.

[Polly Grigora]

phillpot said:

"Standard" relay, yours may have 5 connections but for simple on/off like a fan you only need a 4 pin. Any half decent Motor Factor should have one or Ebay

https://www.ebay.co.uk/itm/221153538914?hash=item3...

5 pin if you want to change like for like

https://www.ebay.co.uk/itm/221233396126?hash=item3...

As above, there is something strange going on when a 5 terminal relay is used to control a single fan

There is always the possibility that there are 2 fans fitted and a 5 terminal relay is being used as part of a circuit that will switch from 1 fan running to 2 fans running if the temperature reaches above a chosen one

[phillpot]

There is nothing strange at all going on, Simply a case of someone slotting a 5 pin in because that's all they had. All the relay sockets in an S fuse board will take a 4 or 5 pin relay,

[mentall]

...or TVR slotting-in a 5-pin because it's all they had!

Simple: check if there's a wire connected to the 87a (normally-closed) terminal in the holder.

[GreenV8S]

I tend to use 5 pin type B relays evreywhere so that they are interchangeable and I only need to carry one spare. The only different ones are the ones with a flyback diode for the ECU controlled circuits.

[jned2]

Relay arrived today, fitted it and took the car for a spin to get the temperature up, the fan kicked in just below the red line, great news. Quick question - apart from old age why would a relay fail?

[phillpot]

Open it up and find out!

coil windings burnt out, contacts corroded or may be just a connection failed?