Chassis Batteries not transmitting power.

[Bruce Sieloff]

Chassis battery pair is producing 12.36V right now (I have had it on a 15 amp battery charger for most of the afternoon), The Coach battery pairs are producing 14.02V. The Echo Ground wire when disconnected from ground and tested with one probe at the Echo and the other to any common ground is putting out 12.5V. Contacting Xantrex they said it is unlikely the Echo is the issue, I must have a positive lead going to ground somewhere, although I don't know where, I've been careful to avoid mixed connections. I have no idea how a ground wire coming directly out of the Echo can produce voltage unless there is something wrong with the Echo. No chassis battery loads that I can find. I am going to disconnect the Echo charger and watch the chassis batteries for continued discharge, maybe the Echo is pulling voltage from the chassis batteries and routing it to ground.

[Edward Buker]

Bruce,

In order to get a good reading you should not be disconnecting the ground wire from the coach chassis ground. It is a reference 0V ground connection that is used by the Echo Charger. All measurements are taken from the ground lead of the Echo charger connected to chassis ground (black probe). The red probe to the + battery post of the battery banks. At 14V the house set are OK.

All you need now, with all Echo Charger leads connected, Red wire to house battery bank + 14V post, Red stripe wire to chassis + battery post, black wire screw lug to frame ground, is to measure the chassis + battery post to ground. You can use the Echo Charger black lead frame connection or your chassis battery negative post for the ground measurement point, readings should be the same.

Your portable charger needs to be disconnected and wait maybe 1/2 hr before taking the reading with the Echo Connected. If that value is not 12.8 to 13.8V then your Echo Charger is defective. That voltage range is wide based on the charge state of the chassis battery set affects this value. Eventually they should be 13V+ while using the Echo Charger when fully charged.

The only other cause of low voltage is if a chassis battery is bad and you have had them tested so that should rule that out. Let us know what you find.

Later Ed

[Bruce Sieloff]

Ed,
Today is moving day. I did the test as you described and am pulling 12.1V at the starter batteries and between the + post on the starter side and a ground on the house side. Same readings. I currently have the generator running to charge the starter side and will test again when we get settled. Don't expect any magic. The 13 volt draw still concerns me. I have done several swaps of the solenoid in the electrical bay, I don't think I swapped any wires but just as a check, which terminal does the ignition ground go on as you face it, FWD or aft?

[Edward Buker]

Bruce,

I think the Echo Charger is bad if you only have 12.1V and your chassis batteries are good and your house set are being charged at 14V when you took the measurement. Not sure what you mean by 13V draw, if that is ground wire lifted off chassis from the Echo Charger and measured to ground do not worry about it. You can have voltage there without current flow when lifted.

Unless the generator has its own alternator, or the Echo Charger is working, there will not be a charging source to the chassis battery set with the generator running. Some had a built in alternator but most did not.

The two solenoid small terminals should have a diode across them. The diode end with the bar on it should go to the + 12V side, the other terminal would be the ground.

Later Ed

[Gerald Farris]

Bruce,
There seems to be a misunderstanding here in the definition for electrical terms. This may put them into nontechnical language. 

Voltage is the electrical pressure that pushes the current or electrons through the circuit, and it is not a measurement for the amount of electricity that travels through a circuit.

Amperage is a measurement for the volume of current that travels through a circuit.

Ohms is a measurement for the resistance to the flow of current through a circuit.

Therefore, as you can see from the descriptions above, the presence of voltage in an open circuit (disconnected wire) does not mean that it is the source of a battery drain problem. The circuit may only be flowing an amperage in the milliamp range because of a high resistance, but it could still have full system voltage when disconnected.

Gerald