Hello All,
One of my many Ford trucks is a 1985 F-250 with the 5.0 FI 302...I've been restoring this bad boy slowly as I drive it almost daily. I recently replaced the VR, alternator, starter solenoid and patched up some old wiring that I found needed fixed...(my alt gauge now works after finding a corroded wire in the harness!)...

My connectors for my fuel pump relay and EEC relay were in pretty bad shape so I ordered new connectors and relays to get that fixed up...yesterday when my wife was driving it, it stalled on her and wouldn't restart...this truck usually starts on half a turn so we knew something wasn't right...so I told her to turn the key and listen for the fuel pump to kick on it...it didn't...so I grabbed the parts that arrived a few days ago and went out and changed the harness and relays on the side of the road...truck fired right up and I brought it home...so we loaded the kayaks and headed out to float...on the way the truck died again...UGH...turn key...no fuel pump sound...now what?....

I've noticed a relay that hangs down below my dash above the gas pedal and it was taped up for some reason...so I unwrapped the tape to find out that the relay casing was broken and I could see the coil / contacts inside so just for S&G's I push the contacts closed and BAM...the fuel pump kicks on!!...I always thought that the EEC relay and the fuel pump relay (driver's side fender mount) were the only two that controlled the fuel pump...so here is my question...

What relay is this?...any ideas on part number?...

I'm thinking that after replacing most of my electric components the stronger current running through my system is finding the weak points and blowing them out or causing malfunction... thanks in advance for your thoughts...this board has helped me TREMENDOUSLY with all of my trucks...but this '85 is my favorite...

 

Maybe the "Inertia Switch" (cuts fuel pump off in the event of a collision).

Post a picture -or some numbers.

 

Look on the relay for its ID engineering number, post what it is.

 

Here are some images of the relay...just drove the truck and I can say this thing was HOT when I removed it...I see no markings other than FORD...this part must be pretty stinkin old....case was broke/cut on it and taped up...

Another thing I notice is this will kick on the fuel pump if you manually close the contacts even if the key is off...




Where it plugs into....



Case is cut/broken...shows Ford logo...



Contact arrangement...



Coil side...

Hope this helps identify the mystery relay...don't think it is an inertia switch because I think those "trip" and have to be reset...this relay is on/off depending on if the coil is energized...

 

If you go down to page 63 in this link

Electronic Engine Control - ???Gary's Garagemahal

You will see the location of the EEC power relay is near the ECA under the dash. I think that relay is the main power relay for the computer. These early trucks where a little different in they way they were wired up.

 

Is your electric fuel pump relay mounted under the hood on the booster side of the firewall like is shown in this link, page 106 and 107?

Electric Fuel Pump Control - ???Gary's Garagemahal

 

Check to see if the wire colors in this photo match the diagram. The diagram has;

white/lightblue

black/lightgreen

yellow

darkblue

 

Thanks for the response...I think you are correct Dave!...I have 2 relays under the hood "near the firewall"...they lay on the fender for now...original mounts are gone...pretty sure 1 is the fuel pump relay and the other is grey...not sure about that one...but the one I need to figure out is mounted next to the ECU under the dash...it is larger than the ones under the hood...makes sense that the EEC relay would be there, I thought it was the grey one under the hood...

I'll take photos in the am and post them for others reference for the '85 folks out there...seems to be an odd year for some things...not sure if the color codes are stock (PO did some "creative" wiring on it but I'll post them anyway)...

Thanks again everyone...this place is a goldmine if you love Ford trucks...