I have a 2000 F-250. The fuse for the vacuum pump that runs the Vent system for the A/C keeps blowing. I have replaced the pump thinking that it shorted out but it still continues to blow fuse. I also unplugged the harness from the pump replaced fuse and it blows as soon as ignition is turned on even with pump disconnected. Any suggestions will be appreciated.

Thanks

 

That fuse goes many places like your front hubs, daytime running lights. Shift actuator,
Speed control module and transmission..Think is there anything that was done to the truck prior to this happening?

Welcome to FTE

 

Everything else on the truck is working properly even with the fuse out. I was thinking maybe there is a relay somewhere that could be bad. I bought the truck used and do not have a manual to trace the relays. It is a 2WD 6 speed so thier is no vacuum to the shift module or hubs. As far as I can tell this fuse seams to only work this vacuum pump.

 

Well with your type of truck the only thing may be the backup lights see if they work with the fuse out if not look for a bad bulb shorted. Or wires etc. No relays as soon as the key is on you get power.

Dick

 

The backup lights are not working. I replaced both bulbs and put a new fuse in. The vacuum pump came on but as soon as I put the truck in reverse it blew the fuse. Where is the backup switch located? Maybe I can check to see if it has a short. Also what size fuse is suppose to be in this spot. Truck had a 10A put have a friends manual for 2001 says 15A?

 

I would check wires under the truck for damage. Check trailer connector . The reverse sw must be on the column underneath the dash . 10A fuse. You have a direct short you have to search for it..Follow the wires where they go to the rear lites...

 

Well I finally had a chance to get under the truck and trace the back up lights wiring. I located the switch and took it out thinking it may have a short. Could not find anything wrong with the switch so I put it back in. When I went to plug the harness back in to the switch I felt a hole in the plastic casing. Pulled the wires out and sure enough both wires were bare on one side. It seems the routing of the wires places them next to the yoke of the transmission and wore off the insulation on the wires which was causing the short. I repaired the wires a routed them in a different direction away from the transmission. Problem Solved!!! Thanks for the help.

 

You are welcome thanks for letting us know how you made out.

 

I have a 99 350 7.3 and my I can't find the fuse for the vent vacuum pump could you help put me in the right direction of finding it

 

Believe it is fuse #28, 10 amps. Powers the vacuum pump motor and some other stuff related to transmission.

 

i didnt see this info in the last fuse diagram i read! this could help me out greatly! can this fuse have anything to do with trans not shifting to 3rd or overdrive? i have first and second fine and reverse. gunna check my reverse lights! and see what happens! fuse diagram i saw didnt say it went to that either .. smh

 

I have had the recurring 28 fuse blowing and thanks to this thread I was able to find the problem. The two wires going to the backup switch had gotten down on the drive shaft and stripped them bare. I managed to manipulate my 75-year-old carcass under there and re-wrap them and tie the wire back.

I just wanted to thank the author of this thread and the people who replied and all these years later you helped an old dude out! Bought the 2000 F-250
new 21 years ago and now I have cold air in my face if I need it. Thank y’all again.