Club 80-90 Forums

What on earth is a retardation relay?
Never seen one, never had to fix one, can't find any info on them but they were however fitted in 1988 to T3 Diesels in relay socket 4 in the fusebox/central electrics.
There is another retardation relay fitted under the back seat of a carat for the lights on the step but I have no idea what the other one is.
Someone ordered one today and Michael asked me what it was and I didn't have an answer for him!
I can see from a wiring diagram for the fuse box that it appears to have a ignition live, an earth and an engine speed signal and that's it.

Any ideas?

Ask Hutch maybe Simon?

I know he has a couple, one on his pace maker and one in his head

Does the van have aircon....if so it could operate the compressor clutch.

what part number ?

Never heard of it...nothing in the wiring books I have...

Aidan wrote:what part number ?

251919082

Switches something off when revs get too low or to high I suppose

I have never found the definitive answer but, I did once read that a retard relay works by applying a time controlled reduced starting voltage ... usually on Ac pumps but I think that VW used them for fuel pumps too. .... as I say not ever found the full answer.

Is the retardation relay for the aircon not mounted in the n/s/r C post. Don't think its for fuel pumps on a diesel!

syncropaddy wrote:IDon't think its for fuel pumps on a diesel!

nope, it was on a VR6 Golf that I came accross it .

Out of Curiosity I tried to look this up. I have the original VW folder with ALL electrical diagrams from 1979-1991. I checked the relay positions and diagrams for 1988 and can't find anything. Position no.4 on the relay board is unused, on petrol as well as on diesel. Do you have a vw part number for the relay or the two digit number on top of the relay?

The only thing I can think of is the GALA relay (Geschwindigkeits Abhangige Lautprecher Anlage) or as it translates to the speed dependant stereo volume. This uses a speed sensor in the speedometer. As the speed of the car increases, the volume of your stereo goes up automatically. It is basically an impulse doubler ( I tried to use it for the speed signal for a VDO cruise control, but used the hall sensor of a Golf mark II instead). This relay is not in position 4 on the relay board however, but on top of the relay box, above the fuses in an extra plastic mounting that clips in.

Just seen this. In the T3 wiring diagrams, relay position 4 is shown wired like this:

Relay pin CE1 connector ref.
1 -------> Connects to eng speed signal (Alternator W) inside relay plate
2 -------> A27
3 -------> A3
4 -------> Connects to term 15 (Ignition) inside relay plate
5 -------> D3, B18
6 -------> Connects to term 31 (Earth) inside relay plate
7 -------> D8

A2 resource CE1 page suggests these pins sometimes connect to a thing they call an 'Upshift relay';

A27 -> Upshift relay pin 2
A3 -> Upshift relay pin 3
B18 -> Upshift relay pin 5, Upshift solenoid shut-off
D3 -> Upshift relay pin 5, Transmission Upshift switch
D8 -> Upshift relay pin 7, Upshift switch, vacuum (Throttle and idle switches, diesel)

Golf part number for the upshift relay is 171 919 091 (marked with a '5'). I think it puts a lamp on at a predetermined engine revs to tell the driver to shift up a gear.

A very quick search didn't suggest this option was ever fitted as standard to the T3, so the fact there's a T3 part number is puzzling.

E D I T: PS. That Golf p/n may be for petrol or diesel, I haven't checked.

Cheers Andy.
I'll have a look at the relay when it turn up and see if the terminals give any more clues.
Customer seems to think their van won't run without out it?

Simon Baxter wrote: Customer seems to think their van won't run without out it?