By Chris Dougherty
Chris Dougherty is a certified RV technician. Here is a letter he received from a reader while he was serving as RVtravel.com’s technical editor.
I have a problem with my converter/charger on my 2006 Winnebago Sightseer. The converter is a Parallax model 7345, which is causing excessive noise on the AM radio band. The noise stops when the converter is shut off, plus the house batteries are never above 12.1 volts. My question is: Can I replace the Parallax with a WFCO converter/charger 45 or 55 amp? Thanks. —Lawrence M.
The short answer is, yes, you can theoretically abandon the lower section of the Parallax system and install a deck-mounted unit. However, it will require the installation of a new deck-mounted converter/charger with an AC receptacle, new appropriately sized wiring for the DC side, grounding, etc. Furthermore, modification of the Parallax power center would be required to run the new wiring in. Not impossible, but should be done with care.
That said, if all the system is putting out is 12.1 VDC, then the lower section has most likely failed anyway. Parallax has a diagnostic flowchart which helps determine this. (This site contains a number of archived documents, including diagnostic flowcharts for several converters, including the Magnatek and BW Phillips lines. Locate brand name of your converter and use the pull-down menu to access “diagnostic” information – ed. )
If you determine that the unit has failed, the company has introduced an upgrade package called the TCRU which will upgrade the converter to a regulated 12 VDC power supply with temperature regulated battery charging. It is a direct replacement for the lower section of your existing unit. According to the manufacturer, the new TempAssure system provides “multi-staged output coupled with temperature compensation.” I think this is not only an easier option, but a better one, as it has the temperature compensation feature which is only available with Parallax and Xantrex (TrueCharge2) to my knowledge. (And here’s a link to help you find replacements – ed. )
The WFCO universal replacement lower section, which is the model you would need, is just a basic converter.
Be sure, whatever you do, to work safely: Make sure power is off and batteries disconnected before working on system. We always recommend having a Certified RV Technician make these kinds of modifications.