91 D50 3.0 fuel pump relay

[Law Dog]

Just got the new truck going the one with the ECU/AIC issue it runs good but the fuel pump relay sounds like a door ajar buzzer. Does not buzz when running but turn it off then after a delay it starts to buzz, moving the key to on will shut the buzzing off turn it back it starts up again? Ran a ground wire to check that ant it still goes off?

Any ideas beyond a new relay?

[geezer101]

I'd be wondering if there is actually anything wrong with it. Are you sure the relay isn't just shutting off and on when it's reached fuel pressure and it's just sensitive? :shrug:

[Law Dog]

It makes noise just sitting there after about 15-20 seconds when the key is off it’s only stops buzzing when the car is running any other key position and will buzz even if I pull the key out it does the same thing?

We did some wire repairs in the battery area “main loom” from rodent damage from when it was parked before I got it might try a new relay then look into why it powers up with that delay if that’s no help. Any ideas on what gets powered up after the key is turned off I might need to take the test light to it one wire at a time.

Once the vehicle it turned off key out of the ignition the battery needs to be disconnected in order to stop the buzzing to prevent battery drain.

Cant get the number on the part to cross reference anyplace to find a replacement one. Found one with 8 pins but mine has 9 pins on it and the plus is divided.

[Law Dog]

Top 3 photos off of truck bottom pic the replacement Rock Auto offers.

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27710&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27709&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27712&stc=1
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27711&stc=1

[Law Dog]

Found a 9 pin one they say it will work on my truck so if its not the relay its in the wire repair area then that's my guess.

[Law Dog]

FINALLY fixed the ECU repair fuel relay buzzing issue on my 91 3.0 it turned out to be the repaired Computer I sent it back a second time and same problem so I was thinking a wire loom problem from chewed wires. I had to put a disconnect switch on the battery to keep from draining the battery or worse.

The repair place was looking for another unit to repair and send me for their cost to see if it was the wiring but I found the right ECU on eBay used, as scary as that sounds but I was desperate to move forward on the project. I was just shocked to even find one that was like Christmas in May.

Now I can put plates on it and insure the thing.

[Law Dog]

If I send the “repaired” computer back they will remove the parts they put on it and refund my repair fee. I’d rather have a good unit but the way it is now its like having a donut spare you would only use in an extreme emergency. LOL