garykd Report post Posted January 19, 2010 Pulled into the Tampa RV Super Show. Went to deploy the jacks and no joy. Key in ACC and HWH panel shows the system is on. When I pushed any jack button the system would make a noise reminding me of someone who is trying to bench press too much weight. Then all the HWH lights would go off, at the driver's control panel. The lights on the HWH circuit board remained on. I know the drill. Document all the lights (off, red or yellow) and call HWH. They called me back the same day! The tech told me as someone pressed the jack button, take a voltage reading between a point on the circuit board and the circuit board ground point. Then take a reading between the same circuit board point and chassis ground. The first reading was 6 VDC. The second reading was 11 VDC. The tech said I had a bad ground. I was to run a new ground wire from the negative side of the pump to chassis ground. I'm not sure how the pros do this, but I was not able to access the negative side of the pump. Newmar put the HWH system on before the coach is mounted to the chassis. Obviously, they never expect anyone of shade tree skill to attempt to get at the pump connections. So, I decide to run a new ground wire direct from the circuit board to the chassis. I remove the seal and front plastic window. Next, I removed the screw holding one end of the circuit board ground wire. Bad decision. I hear tinkle, tinkle, tinkle! There is a nut on the back of this screw that has now fallen to the bottom of the housing for the HWH circuit board. To make a long story short, I had to take out the entire metal housing that contains the circuit board (no small trick). The hardest part was getting the 5 plugs unplugged. Now that the housing was out of the coach I could repair my mistake and use the other end of the wire to make my connection. Put it all back together, then put the assembly back into the coach. Ran the new ground wire to chassis ground. The jacks worked flawlessly. Better than new. All the above took about 1 day. What a way to start the Tampa RV Show. Lastly, the level adjustment needed to be re adjusted. Share this post Link to post Share on other sites
wolfe10 Report post Posted January 20, 2010 Gary, If all you needed to do is ground the board, you did OK. But, if HWH suggested that the pump to chassis ground is bad, you still need to run that ground. You sure don't want the "best ground" for that high amp motor to be through the circuit board. And on most of them (verify with HWH) a pre-made battery cable (auto parts house) from any point on the body of the motor/bolt securing it, etc to known good chassis ground is the ticket. And just use long carpenter's level on the floor to calibrate the level sensor. Takes a little time, but not difficult. Brett Share this post Link to post Share on other sites
cpenn Report post Posted January 26, 2011 Gary, I just experienced the same problem. My ground problem was so bad I burnt up two curcuit boards while trying to find the problem. I finally found the negative side of the motor with a small ground wire going to the back of the circuit board. I wire brushed the connector and bolt but no luck. Evidently the wire went bad because the motor would not budge. I ran a ground wire from the negative side of the motor to the chassis (ground off a new location on the chassis, drilled a hole, and attached a new battery cable with screw & nut). So far, jacks have worked flawlessly. I do not understand how you can use a small ground wire, which was not attached to the chassis, on a high amp motor. I also have a Newmar so I assume the pump was installed the same way. In my opinion this is just a shortcut that is doomed to fail from the start. Thanks for your post because it got me started in the right direction. Charles Share this post Link to post Share on other sites
garykd Report post Posted January 26, 2011 Hi cpenn, Thanks for the thanks. Over a year later the HWH continues to work like new. I agree with you, my feeling is Newmar has a bad process. Share this post Link to post Share on other sites