fuel level gauge NOT the sending unit

[Ltk]

so the fuel sending unit was replaced in my truck today and after re-installing the tank and driving it was working fine. after driving about 10 miles i hit a bump in the road, and bam, not working again!!

i have traced all wiring, brand new sending unit, etc...

could a short in the PCM cause this?? i am stumped..

 

[Nighthawk]

Well, my experience with this maybe differ but..

Over the summer I dropped the tank to replace the sending unit as it was starting to read incorrectly. Drop the new assembly in, and left for a road trip a few days later. When i filled up at my destination, the gauge never moved even though the pump clicked off.

So, after prob 3 to 4 more fill-ups with no gauge change (always read 1/8 to 0) I dropped the tank again to find the sender arm & float just floating around in my tank. No evidence of broken parts, snapped the arm back onto the sender and no problems since.

My conclusion was the sender arm & float weren't fully snapped together when assembled an came loose over the trip (350 miles).

 

[Ltk]

my arm and float are fine and still working properly. dropped the tank again when the problem happened, but everything from the fuel tank to the pcm is perfect.

i just dont understand how ONLY the fuel sending unit has short and nothing else does.

could this be soldered and if so has anyone done it? i cant find anybody with similar issues

 

[BigPapa]

Is there anything else that's not working? Have you done anything under the hood lately?

When I first got my truck together I had several issues that were intermittent: fuel gauge did not work, alternator wouldn't charge, and tranny was in limp mode. I finally discovered a connector, the bottom one shown below, that was not completely snapped together.

 

[Ltk]

havent done anything under the hood in a long time.

the only other thing on this truck that does not work is the low beams. when on low, they do not work. when i switch to high beams, both highs and the driver side low come on.

the fuel gauge never budged off of empty until i changed the sending unit then it worked for a little bit until that bump. now again its not working

 

[Ltk]

ill check that connection thanks for the pic!

ive never heard of a pcm being shorted but its the only alternative i can think of.. (except for loose connections like you had)