Hello all! New to the forum - glad I found it! Sorry if my 1st post is kind of long...
I have a 92 F700 22' box truck with about 290K miles on it. It has a 6.6l turbo diesel and a Lucas Gerrling brake system. I only use it maybe 10 times a year and most trips are less than 100 miles round trip. It is fairly beat up but until recently it ran well.
A few months ago it developed an issue where the brake warning buzzer would stay on whenever the truck wasnt actually running - even with the key out of the ignition. The brake lights stayed on also. If I lift the brake pedal up just a bit the buzzer goes off. I have been just disconnecting the batteries when the truck isnt in use though.
I hadnt used it in about 2 months but Sunday I was going to help a friend move so I checked all the fluids (all fine) and I fired it up. The bendix (?) is real weak and only engages the starter for about a second but normally in warm weather that isnt a problem - usually I only have to turn it over 2 or 3 times and it starts right up. Sunday though I had to hit it like 30 times. Once it started it sounded fine though - sounded like it always does anyway. I put it in reverse and gave it some pedal but it didnt move. I had to play a little - put it in drive, give it some pedal, put it in reverse, give it some pedal, etc - and it finally started moving. It stalled on me at the end of the driveway - that has never happened. It started right back up though and I took off. It had about a 1/4 tank so I headed to the gas station about 5 miles away. I never got over 30mph. I went ahead and filled up and headed out. I went maybe another 4 miles still never getting above about 30 or 35mph before I decided to turn around and head home.
When I got home I set the brake, turned the key and pulled it out but the truck kept running... I tried putting the key back in and shutting it off a few times but no luck, it just kept running. A friend suggested that I pull the fuel pump fuse but I couldnt find it so I pulled all of the fuses under the dash, no luck. He then said to look for a fuel shutoff valve but I didnt see anything like that either. Finally I drained the tank (into a couple garbage pails which ruined all that diesel) and it finally shut down.
I believe that the brake buzzer and ignition switch issue are electrical and the lack of power is something else entirely but I dont know where to start looking.
Any ideas?
Thanks!