My '89 F150 (4.9) has the duel tanks. The back works fine. When I switch it to the front, something starts to smell hot pretty quickly. I can't really tell where the smell is coming from.

It seems to run okay although I switch it to the back after a short time.

Is it hard to replace the pump (or dangerous)?

Any fuses or relays to check?

 

Seems maybe you should trace the wire and make sure its not grounding somewhere along its path. Its easy to pop the switch panel off and start tracing from there.

 

i would think it would blow a fuse if its grounding out somwhere or pop a breaker so that does sound kina odd but yeah it can be dangerous when something gets not near your gas tank so if it was me i would look into it pretty quick so it dont go bang!

 

 

I have had fuses not pop. Whole cab filled with smoke for a minute until I could get the window down. It was just a malfunctioning fuse. Or it could be a bad connector melting. Ford of this era had problems with other areas.

 

Unfortunately I haven't had a chance to crawl underneath yet to have a look.

I usually only drive it on weekends around the farm. It's a beater, but I'd still like to get that front tank working right.

Thanks for all the feedback so far. I'll check back when I find something.