vacum pump troubles
Thread Starter
|
New User
Joined: Jan 2012
Posts: 12
Likes: 0
vacum pump troubles
I have a 1999 F250 4x4 super duty desel my vacum pump stopped working , replaced it , still did not work , hot wired the motors, new one and the old one both work but the old one does sound bad , checked the factory wire to the pump and no power , have been looking for a bad fuse but can't find one .
Any ideas ???
Any ideas ???
Lead Driver
Joined: Sep 2007
Posts: 8,180
Likes: 669
From: Scio, OR
The vacuum pump is on fuse 28 in the Central Junction Box under the dash. There are a number of other things running off of that fuse as well (shift lock actuator, DRL relay, vacuum hublock solenoid, speed control module, backup lamp switch and Digital Transmission Range Sensor).
So unless none of that stuff is working either, the fuse is probably OK. It wouldn't hurt to check it though.
Most likely you have a broken wire in the wiring harness. A good chance it's right at the pigtail. You could use a test light to probe the hot wire to find out. It should be hot with the key in the RUN position.
So unless none of that stuff is working either, the fuse is probably OK. It wouldn't hurt to check it though.
Most likely you have a broken wire in the wiring harness. A good chance it's right at the pigtail. You could use a test light to probe the hot wire to find out. It should be hot with the key in the RUN position.
Thread Starter
|
New User
Joined: Jan 2012
Posts: 12
Likes: 0
Well we found a bad fuse under the dash , got the pump running , won't stop though , and it still won't change the AC from windshield to straight at ya , anyway I found what looks like a selinoid bolted on the inside of the fender , 2 vacum lines going to it , I tapped it and the AC change direction but only got it to work once so am thinking this is now the problem .!?
Lead Driver
Joined: Sep 2007
Posts: 8,180
Likes: 669
From: Scio, OR
First thing, unplug the line right at the pump. Put your finger over the nipple. The pump should stop running immediately. If it doesn't, the pump is bad.
If the pump is OK, unplug the 2 lines from the PVH (pulse vacuum hublock) solenoid. One of those lines should go to the reservoir and one should go down to the hubs. Plug the one going to the reservoir. The pump should shut off in a minute or two, as soon as it pulls down a good vacuum in the reservoir. If it does, the PVH solenoid is bad and needs replaced.
If the pump is OK, unplug the 2 lines from the PVH (pulse vacuum hublock) solenoid. One of those lines should go to the reservoir and one should go down to the hubs. Plug the one going to the reservoir. The pump should shut off in a minute or two, as soon as it pulls down a good vacuum in the reservoir. If it does, the PVH solenoid is bad and needs replaced.
Senior User
Joined: Dec 2009
Posts: 199
Likes: 0
The vacuum pump is on fuse 28 in the Central Junction Box under the dash. There are a number of other things running off of that fuse as well (shift lock actuator, DRL relay, vacuum hublock solenoid, speed control module, backup lamp switch and Digital Transmission Range Sensor).
So unless none of that stuff is working either, the fuse is probably OK. It wouldn't hurt to check it though.
Most likely you have a broken wire in the wiring harness. A good chance it's right at the pigtail. You could use a test light to probe the hot wire to find out. It should be hot with the key in the RUN position.
So unless none of that stuff is working either, the fuse is probably OK. It wouldn't hurt to check it though.
Most likely you have a broken wire in the wiring harness. A good chance it's right at the pigtail. You could use a test light to probe the hot wire to find out. It should be hot with the key in the RUN position.
Thread
Thread Starter
Forum
Replies
Last Post
rmh1999
1999 - 2003 7.3L Power Stroke Diesel
14
Jun 2, 2023 11:40 PM
