504: how not to wire a fuel pump

Andrew Buc (abuc@ibm.net)
Tue, 24 Aug 1999 06:26:45 -0700

Since the mechanical fuel pump on my 504 failed 2 or 3 years ago, I've
been using an aftermarket electric pump. Actually, I bought it ~15 yrs
ago for a Saab 96 I had at the time. When I parted out the 96, my
mechanic Glen Edinger hauled the carcass away. When the 504 fuel pump
failed, he dusted off the old electric pump and gave it back to me.
It's one of those rectangular solid-state ones w/a transistor on the
side. I got mine from Bugpack, a firm that sells VW stuff, but I've
also seen the pump under the Facet name.

This past Sunday in Vancouver, B.C., the pump suddenly quit. I fooled
around and tried to hot-wire it w/a direct connection to the battery,
but no luck. Chris Youngson had told me of a Peugeot garage in the
area, so I called him to confirm their contact info: N&M Sports Car
Ltd., 1107 W. 14th St., North Vancouver, B.C. V7P 1J9, Canada, phone
(604) 985-4840.

I called shortly after 8 a.m. on Monday and talked to Nizar, the owner.
I had the car towed out to N&M. Turned out Glen had wired the pump into
the engine-fan circuit. This had been a satisfactory arrangement until
now, but the fuse had blown. (If this seems like an obvious thing to
overlook, I never said I was the world's greatest diagnostician, and my
frustration didn't make for clear thinking.) Nizar's take was that the
current for both fuel pump and fan was too much for an 8A fuse. I asked
if I could have saved myself all this trouble by replacing the fuse.
Nizar said the fuse would probably have blown again. He rewired the
fuel pump so it takes its power off one of the coil terminals. I was