1988 Ford Motorhome 1987 E-350 electric fuel pump problem

Yes we need more wiring diagrams and not so many people changing wires with out a written in stone what they did LOL

Congratulations sister! You persevered. Now you can plan some travel.
That wiring? I don't know... Somebody may have connected wiring for some feature that isn't there, thinking they were solving a problem. We'd need more wiring diagrams.

J-D Good News!!!!!!!!!! She purrs like a baby kitten. Check this out on the steering Colom side closes to under dash, was a red wire connected to a blk/Green wire running direct to the Fuel pump relay via the oil pressure rd/Y
wire. Disconnected the red wire from the blk/green wire and voltage is correct. why I do not have a clue. Also disconnect the ground from neg. and ran it straight to frame. All seems to be happy now. I am going to grab a pole and head on down to the fishin hole. Thank you so much for all your input. I am one happy girl

I really don't think I have to even say this, you're being so thorough, but... Weather Proof your Splices.

Anxiously awaiting a good report!

OK input is good J-D. Wiring now I changed ok here goes. Battery neg. ground wire connected to wire coming from neg. Connected on to ground at fuel relay about 7" spliced in ground wire to screw on motorhome. checked and solid ground.
Next checked to make sure that instrument cluster that the orange turn in to green connected and ground is true. Next I will install new wired hanger and new pump and will connect plug to pins. secure tank and all. I am putting 10 gals. gas in, just insure no foul up. next message will tell whether all if repaired or not. One thing I will say. Any one that is repairing wiring in a auto or house, take the time to incorporate color code, the next owner will praise your name.

If this E350 is plumbed like ours was, full pressure doesn't really reach the Float Needle in the Carburetor. The Supply and Return Lines meet at a fitting right at the Carb. It's a "Y" where Supply, Return, and Carb Feed all come together. Fitting is supposed to restrict Return enough that Carb gets what it needs but the system is never totally shut off when the Float Needle is closed.

I've mentioned in other correspondence that Dealers and many Shops want to replace the entire "Pump and Sender Assembly" NOT just the "Pump Kit." This case is an example of WHY. Sometimes the extra expense and shop profit actually work in the owner's favor.

I think we got this licked took the pump out and this is the one that did not run 5 minutes. The terminals on the pump showed a green/white corrosion which is a short, most often. I found that the power (Hot lead and ground) were rubbing inside on the under side of the lid and the power ground was going to the sending side and A make shift short wire hooked around a lose nut. I removed the pump and hooked to battery and pump no good. I had a spare pump for testing hooked it up to battery and proper ground and son of a buck took off. So $202.00 later new hanger wiring the whole deal for inside tank and new 3 pin terminal will install tomorrow and boy I hope this is the end of this mystery. One little worry is the pump is a max 17 psi min. is 4 psi so could have to drop tank again if to high of pressure, but worth a try

Proud of You! Digging in, doing it Right.

The pump acts like it is not getting power but it is. However no pump no start nothing. I will know more once ZI get it out and I will hook up to battery and see what happens

yes voltage good
ground is good
I have ordered a new plug and apparatus for pump
also. What to do next.?? I am hoping to get the new today Keep fingers crossed that this works