Have a 93 f150 4.9 5 spd two wheel drive. I need to locate splice 400. This is the point that both fuel pumps and fuel gage senders are grounded. Any help would be appreciated.
Dave 14

 

I wonder if @Steve83 comes to the rescue here.

 

It's inside the frame harness section somewhere between the firewall connector (C205) & the take-out for the front tank. Pull the harness out of the split loom cover and spread the wires until you find the splice.

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Why are you looking for it?

 

This truck has been setting for two years when it was parked both pumps worked and the gas gauges also worked. Now the front pump is the only thing which works. Both gas gauges are off the scale on the full side and if I read from the fuel pump relay through the rear pump it only shows 7 1/2 volts. I have checked and cleaned the grounds both near the negative battery terminal and at the point near the left head light. It seemed more likely that the splice was the problem rather than the front / rear tank selector switch.

 

No, the splice is not a likely fault location. The problems are distinct, and NOT directly related, even though they're caused by the same thing: stale gas. Click this & read the captions about the fuel gauge:

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This & the NEXT few show an extreme case of fuel pump failure due to old gas:

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The PREVious several show how to access the tank from above.