09-09-2012, 07:22 AM
Several months ago I noticed my dash gauge for engine oil pressue was pegged high. VMSpc/DDEC were getting a good reading so the project was not on the top of my list.
At that time Richard said:
"I popped the screw head off my sender during the engine work. I actually sourced a new one from NAPA. Sorry but I don't recall the part number.
It's located on the driver side of the block, at the front, at the top of the block.
Good luck reaching it without 8 ft arms.
I had the hatch open when I replaced mine."
Well the time to fix it has arrived. I knew the gauge was okay since I could ground the sense wire at the rear engine junction box and the gauge would zero. I crawled under and looked where Richard suggested, and was happy to see the sender with no wire attached. I felt around and found the convoluted sleeve and the wire within. I made up a small extension with a ring terminal and crimped it on. The knurled nut holding the old terminal was very difficult to get off, but finally it came loose and I hooked up the wire. I started the coach to verify the dash gauge worked now. It didn't! Rats! I removed the wire from the sensor and grounded it and the gauge zeroed, so the only thing left was the sensor. Now I don't believe the sensor failure and the wire breaking could have both happend in that short time. I am assuming when I turned so hard with the pliars to get the knurled nut of the sensor it may have turned inside the housing and broken the connection. Anyway I was faced with getting the old sender unit out. I got my 8 foot arm out, since I did not have access from above.... just kidding. I was able to get a 17mm open end wrench on the base of the sender, but could not put enough pressure way up there to even come close to turning it. I finally hit upon the idea of using a piece of pipe to push on the end of the wrench, and I broke it free
The gauge and sender are VDO. It appears when the resistance of the sender decreases, the needle on the gauge decreases its reading as well. Now to try and find the right sender. There are no other markings except VDO on the sender that I can see. I will use some resistors and try to determine what resistance makes the gauge real full scale - 80 psi. I hope with that much information I can find the correct sender. I'll try to remember to post back the results.
At that time Richard said:
"I popped the screw head off my sender during the engine work. I actually sourced a new one from NAPA. Sorry but I don't recall the part number.
It's located on the driver side of the block, at the front, at the top of the block.
Good luck reaching it without 8 ft arms.
I had the hatch open when I replaced mine."
Well the time to fix it has arrived. I knew the gauge was okay since I could ground the sense wire at the rear engine junction box and the gauge would zero. I crawled under and looked where Richard suggested, and was happy to see the sender with no wire attached. I felt around and found the convoluted sleeve and the wire within. I made up a small extension with a ring terminal and crimped it on. The knurled nut holding the old terminal was very difficult to get off, but finally it came loose and I hooked up the wire. I started the coach to verify the dash gauge worked now. It didn't! Rats! I removed the wire from the sensor and grounded it and the gauge zeroed, so the only thing left was the sensor. Now I don't believe the sensor failure and the wire breaking could have both happend in that short time. I am assuming when I turned so hard with the pliars to get the knurled nut of the sensor it may have turned inside the housing and broken the connection. Anyway I was faced with getting the old sender unit out. I got my 8 foot arm out, since I did not have access from above.... just kidding. I was able to get a 17mm open end wrench on the base of the sender, but could not put enough pressure way up there to even come close to turning it. I finally hit upon the idea of using a piece of pipe to push on the end of the wrench, and I broke it free
The gauge and sender are VDO. It appears when the resistance of the sender decreases, the needle on the gauge decreases its reading as well. Now to try and find the right sender. There are no other markings except VDO on the sender that I can see. I will use some resistors and try to determine what resistance makes the gauge real full scale - 80 psi. I hope with that much information I can find the correct sender. I'll try to remember to post back the results.
Russ White
2016 Winnebago Vista LX 30T
#530 ( Sold )
1999 45' Double Slide - Factory upgrade 2004