Classic fuel gauge problem

Hello Folks.

Just had some extensive welding done on my 1990 classic and prior to the work being done the fuel gauge worked fine..now it doesn't ! it will rise no further than the edge of the reserve marker and the light comes on and off even with the tank full to the brim.

From what i can gather through searching the forum and google i have a problem with either the sender unit itself or perhaps the wiring.
I've checked all the battery connections and nothing untoward there.

so my question is ,before i start cutting access holes in the floor pan are there any wiring connections i should be checking first or any handy hints and tips that anyone could recommend ?

t.i.a
mag

Hi.
Do you trust the garage and are you sure they disconnected the battery.
Is your gut instinct that they fried it? If so go back and just pose the question and see what they say. Other wise see if anybody has got a sender unit you can plug into the existing wireing to see if thats at fault rather than doing needless work. I'm wondering if they might of melted the wiring somewhere. Just a thought.

Cheers Nick.

First check around the weded area for damaged wires as Nick said, If it is sender ther should be an access panel in floor, if not its easier to drop tank a bit than cut holes.