Due to an overwhelming response to my first such missive (one guy said it was good stuff) I feel emboldened to try it again.

My '70 has the pump mounted approximately midships under the kitchen cabinet. The converter is near the rear end and the switch that controls the pump is at the opposite end of the trailer.

The pump is a fairly husky little motor that draws significant current --particularly just before the pressure switch shuts it off, The wiring that supports this operation is probably no bigger than 16 gauge.

Given these conditions, and the overall length of the wire run, it should come as no surprise to anyone that the pump operates in somewhat less than a sprightly manner--particularly after several days of parking in the boonies. No solar panels here just yet, y'know.

Not wishing to offend anyone, but it's a sorry piece of DC circuit engineering.

The cure:

The pump is current starved. It needs to have some beefier wire (I used 10 gauge "monster speaker" wire) run directly from the same distribution point in the converter that supports the pump to a suitable relay mounted at or near the pump. Radio Shack (I swear I have no stock in this outfit) sells an excellent relay for this purpose.

The circuit is modified so that the switch merely "arms" the relay. The pressure switch turns on the relay which, in turn supplies the current to the pump (via the 10 Gauge wire.)

Be sure to include the ground return in your 10 gauge circuit--thru the other conductor, of course.

You will be pleased with the decided improvement in pump operation and the reduction in the flickering of the lights when it operates. Everything is controlled as before--therefore, no "training program" is required.

Now, does anyone have an ammeter in their trailer that doesn't seem to do anything? I know why . . .

Clark
WA7GGV
27' '70