Hi all! I have a 99 F350 7.3L that just had a new fuel heater put on 2 weeks ago because it kept blowing my 30amp fuse when I tried to start it. Its cold here so I do plug it up and it was still doing this. So two weeks ago its replaced. NOW its doing it again. Unplugging the fuel heater allows me to start it but plugged in it just continually blows fuses. I am not sure if should be looking at something else or what? Not long after installing it my battery light started to flicker/pulse when driving also. It stopped a few days ago. I did read on here that it could be the alternator. I had it tested 2x and it reads good. I have 2 brand new batteries that were installed last month. any tips or ideas on what to look for? Thanks!

 

Are talking about the block heater? If so, was just the heating element changed? If it was, maybe you need to replace the wiring too.

 

We replaced the fuel heater unit, block heater is good. They told me the fuel heater keeps the fuel warm for start up? It was only like a $100 part. But if I have truck plugged in at block heater(I unplug before starting) and disconnect the fuel heater truck will start. If I have the fuel heater connected it will not start and blows fuses. Its got us and few others stumped. Even the guys I work with aren't sure and they work with diesel trucks almost daily

 

Replace the alternator before you get stuck/stranded. It is definitely bad but it is not the cause of your fuse blowing issue.

— Dave

 

Unplug the fuel (bowl) heater and leave it that way. It's an unnecessary accessory that'll leave you stranded. The PCM and the bowl heater are on the same 30 amp fuse and that's why your truck is dead.

Your battery light flickering could be your alternator but you really need to check all of your grounding points. My guess is that your body to frame and frame to engine ground straps are disintegrated and/or missing completely.

Also, go back and get your money back from whoever replaced your fuel bowl heater. They should have known better.