Topran 103 420 fuel pump relay

Hi

Have had an ongoing problem with the fuel pump relay on my Mk1
I set out the problem in detail in a post yesterday.

I have since checked my fuse box and I think I have identified the problem.

The Topran relay that I have (bought new) only activates when the switched ignition 12v is connected to
the pin marked 31 with negative going to pin 15.
It will not work if the connections are reversed with the positive connected to pin 15 and earth to pin 31.

The fusebox wiring is the other way round !!!

When the relay is inserted into the fuse box the 12v switched is at slot 4 on the fuse box and connects to
spade 15 on the relay with the earth (slot 1 on the fuse box) going to spade 31 when the relay is inserted.

Is the problem with my fuse box (everything else works ok and fuel pump works with a number 18 relay)
or the relay?

Has any other member had a similar problem

Thanks



 

Whilst I don't think your issue is in the fuse box, as they can't be bassackwards wired as if you take a look at the internals they look like this:



It is probably an issue with your relay that you bought being bad.
If a horn relay operates the fuel pump then you know it isn't wired incorrectly and that the relay is the issue.
Yes new to you parts straight out of the box have known to be bad from time to time.

 

Now if your old relay has the Fuse at the top of it, and your new one doesn't, then I would suspect that even though they say the new part is compatible, it isn't

Take photos of your old one and your new one so we can see, that is the top and bottom, and the internals if you can get the covers off…..

Me thinks your new relay is either incorrect for your car, and or bad.

Also the Year Make and Model is important as
GTI to me is about 4 different versions.  as in Vert, or hardtop GTI as the Vert was made at the Karmann Coachworks Plant whereas the hardtop was made at the VW plant.

PMH169 said

quote="Briano1234"]Now if your old relay has the Fuse at the top of it, and your new one doesn't, then I would suspect that even though they say the new part is compatible, it isn't

Take photos of your old one and your new one so we can see, that is the top and bottom, and the internals if you can get the covers off…..

Me thinks your new relay is either incorrect for your car, and or bad.

Also the Year Make and Model is important as
GTI to me is about 4 different versions.  as in Vert, or hardtop GTI as the Vert was made at the Karmann Coachworks Plant whereas the hardtop was made at the VW plant.

HI,

Have attached photos of the fuse box in my car and the two relays that I have been supplied.
Neither work.
The Topran has the larger spades but the connections do not mate up correctly.

Thanks again for the help and advice
Very much appreciated.









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Don't reply back to me only posting to your thread is more likely to get you the proper answers quicker.

You forgot the year of the Car.....

Build date: 31:12:1980
Date of first registration: 01:02:1981
Original engine number: EG262410
Replaced with engine number: EG 155512 (1.6 manufactured June/July 1979)

Fuse box fitted is, I think, a model CE1

Hi,

Have run a few checks on the wiring and fuse box.

Connector B19(red) has a red and black wire to the rev counter which works fine.
Connector D26 (white) has a red/black wire which runs back to the coil negative.

What I seem to have on the fuse box is as follows:

Slot 3 runs to the fuel pump and is ok
Slot 2 is the permanent 12v fuel pump supply and is ok
Slot 4 is the 12v ignition switched supply and is ok
Slot 1 is the negative and is ok
Slot 7 runs to the coil negative and is ok.

Have checked the coil negative when the engine is running and it shows 11.58v.

The issue seems to be that the Topran relay has the switched 12v and negative positions reversed so will not work.
Thanks