Title says it all.

1986 e350 cut away 460 carb dual tanks

rear tank pumps fine and vehicle will run on rear tank

cannot switch between tanks

cannot get fuel gauge reading on either tank

fuel selector works when 12 volts applied directly to it from battery

currently have switch E6UB-9A050-AB wondering if this is the wrong one and should use aftermarket switch sw48

 

Does this link help any?
https://www.ford-trucks.com/forums/1...nk-wiring.html

 

Dave,

Thanks, but actually that link is the reason for my question. I guess what I'm asking is E6UB-9A050-AB some non compatible switch that the PO installed (presumably in a roadside jam) and is now causing me problems trying to get back to factory. That's what I get from that link but looking for verification from the experts. Thanks again and sorry for my thickheadedness.

 

I opened up the dash on the van and that switch and connector appears to to have come stock, so something is amiss. Sure wish the parts numbers guy could clear things up for me here. I haven't tested the selector valve plug from the harness to see if power is coming to pins 1 and 2 yet.

One question, are both pumps supposed to have power all the time and the selector valve merely lets one of them push fuel to the carb?

If that is the case then I know the pump in tank 1 is shot.

 

You might post a response in that other thread Franklin listed, possibly subford is subscribed to it, he'd get the e-mail and might come check it out.

I doubt many people here know what SW48 is....

No. Only one pump & sending unit get power at a time.

 

There are no Ford part numbers marked on parts after 1956. Only casting and ID numbers (when applicable).

Marked with ID number: E6UB-9A050-AB = Ford part number: E6UZ-9A050-A .. Fuel Tank Selector Switch / Available from Ford

Applications (Cut-Away makes no difference): 1986/2001 E150/350 (probably after 2001 as my parts catalog ends in 2001).

MSRP: $53.38 // FTE Ford Dealer Parts Dept sponsor tousleyfordparts.com price: $32.30.
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Does the problem lie with the switch? Or does it lie with the fuel tank selector valve that has been a notorious POS from day one?!

1986 E250/350 (gas) & 1985/86 F250/350 (gas) (all over 8,500 lbs. GVWR):

There are two different valves, one has 3 ports, t'other has 6 ports. The 6 port valve is a more notorious POS than the 3 port valve!

E5TZ-9189-A .. Fuel Tank Selector Valve ~ 3 ports / Marked with ID number: E57B-9F271-AA

E5TZ-9189-B .. Fuel Tank Selector Valve ~ 6 ports / Marked with ID number: E57B-9F271-BA or E67B-9F271-AA

 

I believe the switch is ok. With the van running and switch to side A (not marked)I can get voltage (12 or greater) across pins 1 and 2 and across pins 5 and 6. When I switch to side B voltage reverses to pins 2 and 3 and also pins 4 and 5. My best guess is the switch works.

Now I cannot get any readings at the tank selector valve connector at all. With the van running, neither a meter or test light show anything on wires 1 or 2. When I jumper ports 3 and 4 or 4 and 5 the fuel gauge doesn't even bump away from below E. I only put about 5 gallons back in after changing the pump in the rear tank, but that should at least register, right?

Just for kicks, I unplugged the connector and the van eventually died out and wouldn't restart until I plugged it back in, so I know the voltage to the new rear tank fuel pump is going through that wiring. Any ideas would be helpful. Thanks again.

 

5 gallons may not be enough. But you need to make a decision. Do you not put anymore gas in it and take the tank back down and pull the sending unit and check it, or go ahead and put more gas in it to see if it works. You will have to put at least around 3 gallons in it just to get to the bottom of the float and then the 2 gallons will raise the float a little bit but I don't know if it would be enough to register on the gauge.

Do you remember how much fuel you used to have to put in when the guage read empty? I know when my truck reads very close to empty and I go to the gas station, I usually can only get 15 or 16 gallons in it, and it's a 19 gallon tank on mine. So about 3 or 4 gallons stays in the tank all the time. Sort of like a reserve I guess, and also to keep the pump submerged as much as possible in the case of your truck. The fuel keeps the pump cool, and it's generally known it's better to keep the tank from getting too low when a electric pump is used inside the tank.

 

FYI, the tank selector switch connector was unplugged. In the engine compartment near the drivers side firewall, under the power steering pump the connector was dangling. Plugged the connectors together and now have fuel gauge and can switch between tanks. The front tank fuel pump was shot so had to replace that, but it was better than buying a selector valve. Been using the camper with only the rear tank and no fuel gauge all the while, what a pia!

 

Thanks for the followup! Wish more people would do that....