Battery Merge?

[Brian Hunter]

Our 1983 has the standard coach/starting battery switch, meter, and a three way switch (center off, up merge, down merge). When I move the merge switch from the up to the up or down position (in either coach or starting mode) I get a different meter reading. Any ideas out there why this happens? Is it the merge switch or solenoid or? :roll:

[TechTalk]

Unless the batteries are merged, you will get different readings on the engine and house batteries. They are independent, see different loads and have different charge sources. If the merge solenoid is working, the voltages should equalize a short period after merging. If the voltage doesn't equalize, it is a good indication that the merge solenoid has failed. Because these solenoids are mechanical, have a finite life, and are not expensive, we recommend they be changed annually rather than waiting for a failure that might be inconvenient. Later model coaches also have an Echo Charger, a small Heart Interface device wired between the engine and coach batteries, that trickle charges the engine batteries from the house batteries anytime it sees more than a small voltage differential between the two. This is a passive device. It relieves the need to merge the batteries to keep the engine battery charged while the coach is in storage. They can be easily retrofitted and are nominal in cost. You can buy them from Newell parts.