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Topic: 1987 Grand Villa - coach and engine battery confusion (Read 1449 times) previous topic - next topic

1987 Grand Villa - coach and engine battery confusion

There appears to be a mix-up between the coach and engine batteries on my recently purchased MH. Below are the anomolies that I have observed and I wonder if they are all connected.
1. When I turn the ignition switch to Acc, the dashboard gauges power up just as they do when I start the engine.
2. While replacing the radio fuse (earlier post) I noticed a blown 20 amp fuse marked "Battery accessories".  I replaced the fuse, isolated the coach batteries (or so I thought) via the isolator switch and left the MH for 3 days.  Upon my return the engine batteries did not have enough charge to turn the engine over and the coach 12V system was energised even though the isolator switch was "off".  I removed that 20 amp fuse and the isolator switch worked as it should.
3. I charged the engine batteries overnight then decided to top-up the coach batteries.  I disconnected the "coach" batteries (2 in parallel.  There are also 2 for the engine) yet the monitor showed them to be almost fully charged.  Therefore the monitor must have been reading the engine batteries.
4. The charge/boost switch does not illuminate when activated.  I have yet to check the switch continuity.
The wiring diagrams in my manuals are not comprehensive.  Does anyone have any ideas?

Further to the above, I have activated the charge/boost switch and heard a click which I assume is the solenoid kicking in.  Also, with the engine batteries negative terminal disconnected and the coach batteries connected the coach battery monitor is dead but when I activate the charge/boost switch then the battery monitor and all the other monitors and instrument gauges work OK. So the charge/boost switch appears to be working although it does not illuminate.  I guess that I need to find the wire that feeds the monitor from the coach batteries.

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #1 –
You probably need to replace the light in the boost switch.

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #2 –
Get out the Owners Book and check wiring diagram, mean time use the Salesman's Switch located by the door, just turn everything off when not using.

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #3 –
Quote from: Steve & Nancy Snow –
Get out the Owners Book and check wiring diagram, mean time use the Salesman's Switch located by the door, just turn everything off when not using.
Be aware that the "Salesman's Switch" turns off a lot of stuff. However, it does not turn off everything that operates from the house batteries. It also does not turn off any loads on the chassis batteries. There are usually some small loads that will drain the batteries even when all switches are off. The most reliable way to disconnect everything from the batteries is to disconnect the negative connections at the battery posts.

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #4 –
Thanks, people.  The wiring diagrams in the manuals are pretty basic and do not show all the wiring and the Foretravel Owner's manual is not vehicle-specific.  I do turn off the coach batteries with the door switch and that is satisfactory now that I don't have a fuse in the "Battery Accessories" fuse holder.

I shall contact Foretravel and see if they have any comprehensive wiring diagrams.

Thanks again

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #5 –
Quote from: J. D. Stevens –
Be aware that the "Salesman's Switch" turns off a lot of stuff. However, it does not turn off everything that operates from the house batteries. It also does not turn off any loads on the chassis batteries. There are usually some small loads that will drain the batteries even when all switches are off. The most reliable way to disconnect everything from the batteries is to disconnect the negative connections at the battery posts.
Isnt there a battery isolation switch that isolates all the battery power,
Instead of disconnecting the negative leads from the batterys,
The PO of mine said he was replacing the battery isolation switch as it was a bit dodgy,So I assumed it would disconnect the batterys totally,

I have no idea, As I havent even seen my bus yet, All info is very helpfull. Thanks,

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #6 –
Quote from: MR B2 –
Isnt there a battery isolation switch that isolates all the battery power,
Instead of disconnecting the negative leads from the batterys,
The PO of mine said he was replacing the battery isolation switch as it was a bit dodgy,So I assumed it would disconnect the batterys totally,
I just checked the wiring diagram for our 1997 U295. The battery disconnect switch by the entry door does not disconnect the refrigerator control, LP leak detector, dash memory, or amp-hour meter. Those items remain connected to the house batteries. They will continue to draw power even when the battery disconnect switch is off.

I was not able to identify any specific loads on the engine batteries from the diagrams. There will likely be voltage sense line to the alternator, and there may be other loads on the engine batteries. The previous owner of our coach had connected a satellite phone to the engine batteries (old technology wired to the wrong circuit).

If a coach is without external power for more than a month, it would be prudent to disconnect the battery cables at the posts and protect the terminals from accidental contact.

 

Re: 1987 Grand Villa - coach and engine battery confusion

Reply #7 –
JD is correct as some items are left powered on. Some are safety related. That is why I suggested earlier that the neg terminal be disconnected.
John