dual fuel tank only 1 working

I just bought 1991 f150 4.9 dual tank the rear tank works fuel level and pump switch it to front and gauge drops to bottom and no noise from pump and will not
start checked all possible contacts and did not see anything unusual is there any way to check wiring for power or any good thoughts?? I was about tempted to make some jumper leads to see if pump is good (taking wiring off rear tank and put to front to make sure not issue in tank) just grabbing straws
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jump it accros at the selector valve much closer than trying to get at the tank wiring. KB
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On Fri, 28 Mar 2014 21:08:48 +0000 (UTC), Kevin Bottorff

Which won't tell you if it is a bad wiring problem or a fuel level/pump issue.
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snipped-for-privacy@snyder.on.ca wrote in

he wanted to start by testing the pumps, thats the easiest way. KB
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On Sun, 30 Mar 2014 20:17:27 +0000 (UTC), Kevin Bottorff

But if the pump does not work he STILL doesn't know if it's a bad pump or bad wiring. To test the pump you need to apply power AT the pump. If it works jumpering the selector but not with the selector all you have tested is the selector. If it doesn't work, you have not tested anything.
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snipped-for-privacy@snyder.on.ca wrote in

see

at

the rear pump is working, so taking power off the selector valve means he HAS know power supply and is right by front tank too. Get it???? KB
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On Mon, 31 Mar 2014 16:45:34 +0000 (UTC), Kevin Bottorff

Someone is not understanding someone else here.
If by "jumpering" you mean taking power from the selector switch and using jumper leads going directly to the front pump, yes that will work. If, on the other hand, by "jumpering" you mean bypassing the switch or connecting the wires from the selector switch to the front pump to the connections at the swith for the rear pump, then my concern is valid.
"jumpering" is a bit ambiguous. Jumpering "at the selector switch" sounds a whole lot like making all the test connections "at the switch" because it is closer and easier than "trying to get at the tank wiring" which I interpreted as getting to the front tank wiring.
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snipped-for-privacy@snyder.on.ca wrote in

pump

any

all

means

both front and rear tank are hard to get at directly unless you lower the tank, so do the quick test first at the selector valve on the frame rail right next to the fr tank. if that fails you can know either way your dropping the front tank. if it works then nothing else is required outboard of the selector switch, (which are not unusual to have problems, as is the pumps in the tank going out.) KB
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