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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: hargreaves on July 08, 2008, 08:43:15 AM

Title: MCI 102A3 Power draw
Post by: hargreaves on July 08, 2008, 08:43:15 AM
Well I got the roof all raised and some interior done, well, enough to take the bus and the boys on a golf/ shakedown cruise . I noted the starting batteries were getting run down. It seems the relays for the operation of the air that opens and closes the door are always on even when the coach is not running. Is this normal or has something been modified. It draws enough power to kill the batteries in two days. I don't as yet have a manual so if I could pick the brains of all you wizards out there it would be appreciated.   Thanks in advance   Gerry.
Title: Re: MCI 102A3 Power draw
Post by: Dallas on July 08, 2008, 09:03:39 AM
This might be a dumb question, but are you turning off the master battery switch in the battery compartment when you shut the bus down? If not, all your systems except for a few things are hot.

Make it a habit to turn the master Battery switch off every time you shut the engine down.

IHTH,
Dallas
Title: Re: MCI 102A3 Power draw
Post by: hargreaves on July 08, 2008, 09:30:04 AM
Hey Dallas, I quess that means I have to bleed the air off the doors, because when I shut the power off the door slams shut or is there a mod that is done so the door can be used?
Title: Re: MCI 102A3 Power draw
Post by: Hartley on July 08, 2008, 11:03:56 AM
Quote from: hargreaves on July 08, 2008, 09:30:04 AM
Hey Dallas, I quess that means I have to bleed the air off the doors, because when I shut the power off the door slams shut or is there a mod that is done so the door can be used?

You should have a manual release valve somewhere under the dash or near the door...

Just my thought since mine has one.
Title: Re: MCI 102A3 Power draw
Post by: buswarrior on July 09, 2008, 08:25:43 AM
The PA amplifier can be a hidden parasite often overlooked, depending on what happened to the various microphone wiring during tear out.

happy coaching!
buswarrior
Title: Re: MCI 102A3 Power draw
Post by: hargreaves on July 09, 2008, 09:12:51 AM
Thanks BusWarrior, I find it hard to believe that the manufacturer would have that much of a power draw when the coach engine is off but the batteries are still on. When I pull the two relays in the front AC compartment that control the air valves for the door operation , the load goes away but then I have no door operation. I wonder if anyone has modified them to only work when the engine is running. Or maybe even better disconnect them altogether and open and close the door manually and put in a door latch. The mic equipment has been removed.       Gerry
Title: Re: MCI 102A3 Power draw
Post by: Busted Knuckle on July 09, 2008, 09:22:05 AM
Quote from: hargreaves on July 09, 2008, 09:12:51 AM
Thanks BusWarrior, I find it hard to believe that the manufacturer would have that much of a power draw when the coach engine is off but the batteries are still on. When I pull the two relays in the front AC compartment that control the air valves for the door operation , the load goes away but then I have no door operation. I wonder if anyone has modified them to only work when the engine is running. Or maybe even better disconnect them altogether and open and close the door manually and put in a door latch. The mic equipment has been removed.       Gerry

Gerry,
You maybe onto something, I have a manual door opening closing system on my 102A3 and would like to convert it to the air operated door. Wanna swap parts? ;D  BK  ;D

PS by the way we always turn our batteries of on our MCI's if it is going to be "overnight" or more before restarting. Our Setra's have a soleniod that does it for us!
Title: Re: MCI 102A3 Power draw
Post by: hargreaves on July 09, 2008, 11:18:28 AM
BK,
I would like to keep the air operated door if possible. I'm interested in the solonoid system you have. Does it shut all the power to the coach or just some parts.     Gerry
Title: Re: MCI 102A3 Power draw
Post by: Ednj on July 09, 2008, 11:45:19 AM
One of my Phantom power draws was the original light in the bays,
The button switches were rusted badly.
Just throwing it out there something else to check.
;)
Title: Re: MCI 102A3 Power draw
Post by: Busted Knuckle on July 09, 2008, 04:36:27 PM
Quote from: hargreaves on July 09, 2008, 11:18:28 AM
BK,
I would like to keep the air operated door if possible. I'm interested in the solonoid system you have. Does it shut all the power to the coach or just some parts.     Gerry

Gerry,
To my knowledge it shuts down the whole 24 Volt system. But it must leave something on in order for it to work with the key! When you turn the key on you can here the huge relay click on. There has to be power somewhere for it to be able to do that! I'll see what I can find out about it. The other offer still stands though! LOL! ;D  BK  ;D
Title: Re: MCI 102A3 Power draw
Post by: Sammy on July 09, 2008, 04:47:05 PM
Prevost uses that main battery disconnect switch too.
There should be a small handle with a small red ball on it, just above or just to the right of your right knee (when you are in the operator's seat).This controls air pressure to entrance door cylinder.
Title: Re: MCI 102A3 Power draw
Post by: Sojourner on July 09, 2008, 05:24:27 PM
Gerry....I think you are not aware that your MCI come with master shut down switch on the side of battery compartment. That cut off all OEM connection to the batteries.

FWIW

Sojourn for Christ, Jerry
Title: Re: MCI 102A3 Power draw
Post by: hargreaves on July 09, 2008, 10:02:10 PM
I see the red handle . Does it bleed all the air from the coach or just the doors?  also you have to hold it to bleed the air.  I'm an impatient guy, lol .I know there is a master switch but being as absent minded as I am I forget to turn it off.
Title: Re: MCI 102A3 Power draw
Post by: Busted Knuckle on July 10, 2008, 04:33:59 AM
Quote from: Sojourner on July 09, 2008, 05:24:27 PM
Gerry....I think you are not aware that your MCI come with master shut down switch on the side of battery compartment. That cut off all OEM connection to the batteries.

FWIW

Sojourn for Christ, Jerry

Jerry if you reread what's been posted he's aware of the power cut off, but he's looking to avoid the door automaticlly closing when the power is shut down! (unless he lets the air pressure off it first!) FWIW ;D  BK  ;D
Title: Re: MCI 102A3 Power draw
Post by: belfert on July 10, 2008, 06:05:27 AM
Couldn't the door mechanism be reworked to work off the house batteries if the house system is 24 volts?

I think the bigger problem will be lack of air for operatiing the door after going in and out for a few days.  An auxiliary 110 volt compressor would take care of this.
Title: Re: MCI 102A3 Power draw
Post by: Sojourner on July 10, 2008, 11:23:24 AM
Thank BK.....I am sorry for rambling on. Your right....
Quote from: hargreaves on July 08, 2008, 09:30:04 AM
Hey Dallas, I quess that means I have to bleed the air off the doors, because when I shut the power off the door slams shut or is there a mod that is done so the door can be used?
.....Try to be more careful next time.

Sojourn for Christ, Jerry
Title: Re: MCI 102A3 Power draw
Post by: Busted Knuckle on July 10, 2008, 03:31:21 PM
Quote from: Sojourner on July 10, 2008, 11:23:24 AM
Thank BK.....I am sorry for rambling on. Your right....
Quote from: hargreaves on July 08, 2008, 09:30:04 AM
Hey Dallas, I quess that means I have to bleed the air off the doors, because when I shut the power off the door slams shut or is there a mod that is done so the door can be used?
.....Try to be more careful next time.

Sojourn for Christ, Jerry

Not a problem Jerry, just trying to point out the issue at hand. Also still willing to trade Gerry opening systems! LOL! ;D  BK  ;D
Title: Re: MCI 102A3 Power draw
Post by: hargreaves on July 10, 2008, 08:04:07 PM
Don,t mind opening and closing the doors manually once the air has gone it,s either bleeding through the red knob ( time consuming) or pumping the brake pedal (looking like an idiot in a campground) or waiting the six hours for the air to  bleed down, by that time ( a few whiskies later i've forgotten to turn off the batteries( gee I wonder why)    Gerry.
Title: Re: MCI 102A3 Power draw
Post by: Sojourner on July 10, 2008, 08:36:04 PM
You can add a 2-way solenoid between cylinder & line and power from after master switch power source. Every time you cut master power off....it will stop air to cylinder as well bleed to manually open & close folding doors.

Grainger has normally close valve with bleeder or exhaust.

It may already have it installed from the factory....trace the line from cylinder until you see 2 solenoid valve...one is normally open "NO" and the second one is "NC".

FWIW

Sojourn for Christ, Jerry
Title: Re: MCI 102A3 Power draw
Post by: Lin on July 10, 2008, 09:03:06 PM
I have never turned off the main switch on my 5a, and the batteries have never shown any signs of discharging.  Is this admonition to turn off the battery disconnect just for later models?
Title: Re: MCI 102A3 Power draw
Post by: Sojourner on July 11, 2008, 05:31:42 AM
About the whys of the "cut-off" master switch:
1)   All electrical appliances are inoperative.
2)   All drivers' control panel is inoperative.
3)   Alternator's hot post is dead to avoid normal diode (0 to .5 volts) drainage.
4)   Most MCI are not equips with keyed switch.
5)   Locked batteries & master switch entry door or cover for thief proof.
6)   Less chances of electrical (high-current) fire while no one present.
7)   No parasite load while shut down.
8)   No need to turn off interior lamps that the passenger left-on.
9)   ....someone on board may have more to add to the list? ? ?

FWIW

Sojourn for Christ, Jerry