Fuel Pump Relay location and replacement 1984 GN

Hot Air Beast

Hot Air Lover
Mar 10, 2007
Close to Ottawa, Ontario, Canada
There have been a number of inquiries over the years as to the exact location of the Fuel Pump (FP) relay on a 1984 Grand National. As I once again have an FP problem I began to refresh my memory.

In the GM manual, Driveability and Emissions - Fuel Injection 6E3-183 figure 180 G series 3.8L, it is plain to see that there are four sensors on a single bracket bolted to the passenger side inner fender on a 1984 GN and I believe this to be the same for the 85.

The one closest to the firewall is the ESC Module
The next one, moving towards the front of the car, is the AC Cut out relay
The next one, towards the front of the car, is the FP relay
and the fourth one, is the Boost Guage Sensor (MAP sensor).

The FP relay has a grey connector, while the AC cutout relay has a black connector.

As the GM manual says "Other than checking for loose connectors, then only service possible is replacement".

I always disconnect the positive side of my battery whenever touching anything electrical.

I found the easiest way to remove the FP relay is to remove the entire bracket with the sensors intact ( two self tapping screws). Once removed, flip the bracket over and pry the metal retaining prong holding the FP relay in place, up ever so slightly. Then push the relay up towards the top of the bracket.

Once the relay is removed there is a small prong portion of the grey connector on the single wire side. Gently pry it up while pulling on the connector. The entire connector will come off revealing the three contact side and the single contact side. It is not necessary to open the hinged sides of the grey plastic.

Push the connector onto your new relay and place the relay up as close to the underside top of the bracket and pull down onto the metal relay support. Once the relay is fully down onto the support push the metal retaining prong back down. This ensures that the relay will not work its way loose, although for the life of me I cannot see why this prong is necessary except to make my life more difficult.

Job is done - re-screw the bracket to the inner fender well.

Hope this helps.

ps if anyone needs info from a specific part of the GM manuals pm me and I will copy and email the part of the manual to you. I have a full set of shop manuals that I bought in 1988. Index plus sections 1 through 9 - 11 inches of manuals.


Apr 6, 2017
It seems that the Fuel Pump relay between the 84 and 86-87 is different. Some sites show different part numbers (though not all). Kirban says they are different on his site.

What are the differences? Are they different electrically, or is it the connectors are different?

I bought a relay for my 84 but it didn't fit the connector. (My car had been switched by the prior owner to the 86 ECM, but I don't know how much other stuff has been switched to a later car)

Also, Can the A/C relay next to the FP be used in a pinch as a way of troubleshooting a possible relay problem?
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