924Board.org

skota · Joined: 10 Dec 2021 Posts: 27 Location: Madison, Wisconsin

Hi Folks,

The plug on the back of my factory fuse box is pretty burnt at the A8 port for the cooling fan.

I'm planning on installing a new 40a relay with switch power being tapped into the relay off of one of the ignition switch leads. I found this diagram and wanted advise on if this looked like a reliable way to restore switched power.

Advise on placement on the new relay would also be apreciated.

Thank you for any advise given.

https://imgur.com/a/pZhtCbw[img]

Eliza · Posted: Mon Feb 07, 2022 9:45 pm Post subject:

A8 for the fan? You must have a pre-MY80 car I assume.
From MY 80, A8 would be switched power for the horn.
Is your stock blower relay situated on the lower of the two relay rows?

If yes: A similar situation occurred on very early VW Golf mk1s where the fuel pump relay caused a multipin plug at the rear of the fuse box to burn out owing to undersized supply wiring.
VW advised to re-route the relay to the top row, and supplied for the recall a pigtail with a new relay holder. Give a shout if you want more info on how that was done, or google "early Golf mk1 FPR bypass kit".

The relay holders for the top row are still available from VW. They simply slide into the fuse box. Part no for those holders, which you could wire in, is 135.937.501A.

Also, let me know if you want a wiring diagram how the later blower relays were wired. They have the blower relay on the top row ( apparently for a reason which now we know

)

Eliza
_________________
1985 924 NA RoW
1981 931 S2 RoW

skota · Joined: 10 Dec 2021 Posts: 27 Location: Madison, Wisconsin

Hi Eliza,

I suppose say what car I have would've helped.

It is indeed a pre 80, 1978 to be exact.

I wired in a new relay this weekend and I was wandering about adding a relay holder to the top of the panel so your post is a big help. Thank you!

Steve

skota · Joined: 10 Dec 2021 Posts: 27 Location: Madison, Wisconsin

Here is an updated drawing of how I have things wired now. There are a couple things I'm wondering about this and would appreciate any advice.

1. Will running the power from the relay through the temp switch to the fans be too much for the temp switch?
It looks like this is how it was done from the factory per the factory wiring diagram but I am running the ground from the fans, not through the temp switch.

This worked on initial trial but only one fan came on. I'm going to check the connections to the non-running fan but I'm also wondering if having the ground wires coming off the fans connected may cause this. Yes, electrical is NOT my finest asset.

Thank you,
Steve