tank selector switch prob

[aaklingler]

When I bought my 93 the fuse was blown for the tank selector switch, I put a new fuse in and has has been working fine. Last night I flipped the switch to the front tank and it blew the fuse. Anybody run into this problem before?

 

[franklin2]

I would look for damaged wiring along the driver's side frame to the fuel tank switching unit.

 

[Dsl_Dog_Treat]

Could be a faulty fuel selector valve and it's hanging up partially between tanks causing the switching power to remain active.


Just battled a FSV problem last night myself.

 

[aaklingler]

How did you decide thats what it was?

 

[hesutton]

Ron, have you ever opened up one of the FSV's? I have an old one I'm tempted to open up and see if I can't "rebuild" it.

Heath

 

[Dsl_Dog_Treat]

Heath, I haven't yet. I do intend to once I get the wiring bypassed for the fuel gauge. I may save it for a rally deconstruction item since that of all items is far from my list of things to play with right now.

Yup, Mel had to talk me back off the ledge last night as to not convert Mater back to a gasser!

Being stranded twice in the same night due to the defueling issue and to top it off, a heater core erruption spewing 1.5 gallons of coolant into the cab and fogging the glass over in a blinding snowstorm at 7:30 p.m. was fuel for a very bad night on top of being sick as well.

How did you decide thats what it was?

My problem was more of a flow related problem but talking with Mel last night trying to eliminate a few variables, I had suspected it to be plugged or something as I could hear it switching, but didn't have access to an ammeter to see if the latch was switching between tanks completely, so I just began testing areas in the fuel lines to check for flow restrictions. The FSV was found to be the culprit.

 

[aaklingler]

Is there a way to test it with an ammeter?

 

[aaklingler]

Anybody know how to check the tank selector valve?

 

[bushpig7]

had one apart recently

I rebuilt my fuel tank selector valve on my 93 crew cab. the one I have is a pollack almost identical (except for a slightly different plug) to pollack's part no. 42-159. The valve changes positions when the polarity on plug terminals 1 &2 is reversed. you have to drill out the four rivets to get it apart but it isn't all that complicated. there's only about three things that could go wrong with it:
a build-up of "crud" on the internal contacts (that was my problem), worn out seals in the actual valve part, or worn electric motor and the screw feed system in there that actually moves it forward and back. I just cleaned the contacts and replaced the old dirty grease with new light grease (brake slide grease would be perfect) . I lined up the motor with the connector, put it back together with nuts and screws where the rivets had been and it works like new. If the seals are done I think you would have to throw it away since they are locked into place by melting and repositioning part of the casing at the factory. and if the screw feed aparatus wears out you would have to harvest parts out of another which defeats the purpose of taking it apart if you have to get another one anyway. I bet that the most common reason for failure is dirty contacts inside where they slide back and forth . Also, a cold solder joint could cause failure (there are 3 or four solder joints inside).