View Single Post
JFairman JFairman is offline
Registered User
Join Date: Jul 2006
Location: S. Florida
Posts: 7,274
You should connect an ammeter across the pins you would jump in the red relay sockets to see how much current each fuel pump is drawing while it runs.
Jump pins 87 and 30 on a red relay socket with an ammeter set to the 30 amp setting to make a pump run and check amperage draw of the fuel pump. The pin numbers are on the bottom of a red relay next to the pins.

Do not ever jump those same pins on the yellow relay socket in the rear of the car or you'll melt wire insulation from the socket and see smoke come from under the relay panel... BTDT.
To check or jump the yellow relay socket you jump socket pins 87a and 86 and the pin location markings are on the side of my 1987 yellow relay, not on the bottom. The yellow relay for a 1987 does not have the brown wire coming out of the side. I don't know what yours is like.

Check them individually while only the pump being tested is running and again while the other pump is running too for a current draw comparison.

You'll probably see the 044 is doing most of the work and drawing more amperage or current than the front pump because it's a bigger and higher flow pump. On top of that you said your front pump has no identifcation markings in an earlier post and that usually means it's a chinese fake bosch fuel pump.

That would be in check with the front pump sounding quieter now while the 044 in the rear is running.
Old 06-19-2010, 11:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)