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Wed Nov 03, 2004 2:55 pm

Hi all, can anybody please give me a description/sketch of the wiring logic of the fuel pump on a 74 L-Jet, 412. I just got the car not too long ago and it wont start. After a long a lot of frustrated trouble shooting I pinpointed the cause. It was a toasted seat belt relay under the fuse box. I bridged the ign wires and now the starter turns but the fuel pump does not. I tried with another good pump, the same result. The relays click but no juice to pump. Is it possible that the seat belt relay also cuts the circuit of the pump? there is 6 wires going into it, are any of them going to the pump? I am really stumped and any help will be greatly appreciated.

Fri Nov 05, 2004 6:57 am

There is a three page thread on the other site, same exact situation. try this:

http://www.shoptalkforums.com/viewtopic.php?t=77101&sid=da0d1ac9b2e1a949866419f1cfe08d09

Fri Nov 05, 2004 7:32 am

Dude, I think it's the same guy.

Fri Nov 05, 2004 11:59 am

by joove, I thinks ye be right. Is that you Longbeach?

Fri Nov 05, 2004 11:03 pm

yes sirry am it! As you can see from the shoptalk thread that we were throwing dodo on the wall and none of it stuck. Then I got real busy and then had an operation and other good things. Just this past week I had the strength to take another crack at her again. In talking with my FLAPS I found out that all 74 vws are plagued with this seat belt relay thing and he said it sound like your relay, and sure enough, it was. Now she cranks but I need to figure out how to trace the fuel pump circuit, physically and schematically to see why the pump isn't running. Whats worse is that I know nothing about L-Jet or type 4s. My knowledge stops at Type 3s and D-Jet. Also it seems st the moment that the shoptalk gang and Ray Greenwood are on a sebatical for whatever reasons, so I am trying my luck here where I have been a member a while back. Thanks for any clues guys. Peace

Sun Nov 07, 2004 1:03 pm

I understand seeking all venues, that's why I'm here (aka 67 T1). You know, I've got two 74 wagons, so your thread has given me an education on potential 'put on your damn seatbelt' problems. :D

I'm still working suspension at the moment, in between trips to DC and other foresaken lands.

Sun Nov 07, 2004 5:33 pm

Hey 67 T1, no kidden. I am finding out that 74 is a year all to itself in many aspects than one. Actually it makes sense when you think about it as it is typical of auto makers to throw all their odds & ends, left over parts and ideas, as well as trying out some new stuff on a doomed last year production. For example I am finding out (not sure yet but almost there) that the fuel pump realy is in the bottom of the fuse box! My question is; since you also have 74s do you know what the relays ( I got 3 in there) under the back seat are for? especially the one on the far right (right is right)?

Fri Nov 12, 2004 11:47 am

The one I am currently working on was piliaged by the PO, as he installed the dreaded double progressive webber. I only remember seeing one relay under the back seat, but will give it another look.

I've not messed around with the other 74' wagon (manual tranny :D ). But it still has fuel inj set-up. Too many tasks and too little time, just like everyone else. I've not even lifted the back seat on it.

I looked in the Bently catalog the other day for 412 stuff, only thing that was in there was the owners manual. That wouldn't be much help.

Fri Nov 12, 2004 10:37 pm

Thanks 67 for the help but I've already moved on. I've gone as far as getting the starter going and figuring out what the AFM does on an L-jet system and proving that the pump circuit is ok. Now am back where i started and the starter is not getting juice again! and right now am going nowhere! every spare minute of my time has gone to waist so far :x . Anyways, my inputs are back on the shoptalk forum. Best Regards

Sat Dec 04, 2004 1:34 pm

Checking...how's it going with your starter/fuel pump problem?