Ideas on jump starting bus, other than connecting to battery?

Adarian · December 21, 2009, 02:08:16 PM

I have a bus with an air starter. I parked the bus in storage and now two of four batteries are dead.
There is a vehicle park next to the bus that prevents me from accessing the battery tray.
I can access the engine bay and the electrical panel.
I need at least 19v to activate the solenoid to the air starter and the fuel cut off solenoid.
Can I hook up a 24v battery pack at the positive cable at the alternator and frame ground to get enough voltage to activate the solenoid to the air starter and the fuel cut off solenoid without frying anything?
The bus is an 88 Flx Metro with 12v and 24v systems.
The alternator puts out 24v and I think 270 amps.
Thank you

robertglines1 · December 21, 2009, 03:13:55 PM

not familiar with your set up at all but mine has a jump and or charging terminal in engine compartment..might be worth looking around in there

FloridaCliff · December 21, 2009, 04:18:11 PM

A lot of Hot rodders use a connection like this as the batteries are usually put under the chassis to make the engine compartment cleaner.

You could wire these in an accessible place for future jump starts.

If you do, and you know this, it will always start.

fe2_o3 · December 21, 2009, 04:52:31 PM

Can you get to the solenoids directly? Do you have rear start? Once it starts it should take care of it self, if the alt. works..Cable

luvrbus · December 21, 2009, 05:02:21 PM

Check your manual the air starter should have a manual override to start without batteries.

good luck

Adarian · December 21, 2009, 05:55:06 PM

I can get to the solenoid, it is under the bus next to the air tank.
I have rear start. Yep once it starts I can move it and replace the batteries.
No manual override, fuel cut off solenoid would need to be energized.
Should have stated bus has a turbo on it. Cummins L10 motor.
I basically need 24 volts to energize the system.
Just wanted to be sure I wouldn't fry anything by adding a power source outside of the batteries.

buswarrior · December 21, 2009, 07:06:32 PM

Just hook up to the alternator post and good to go.

For the rest of the viewers, if you are unfamiliar with air starters, there will be no large surge of current, like there would be with an electric starter. Only the required voltage push to get the solenoid valve on the air starter to open, and the fuel systems requirements as noted.

happy coaching!
buswarrior

RTS/Daytona · December 22, 2009, 05:00:43 AM

I agree with Buswarrior

The big post on the alternator is a direct path to the 24 volt side of the battery - USUALLY VIA THE 24 VOLT CUTOFF SWITCH

bevans6 · December 22, 2009, 06:00:37 AM

Just a bit of an aside comment. When I installed my trailer-light converter, I used a bi-directional 12v/24v converter to adapt my 24 v bus power to 12 v for the trailer. I powered the converter from the 24v buss in the rear junction panel. What I was surprised by is that when I connected my trailer with it's 12 volt breakaway brake battery, I powered up the bus 24 volt system too! Obviously at low power, 20 amp 24 v max, but that would power your solenoid I'm sure. So a system like this would possibly be a way that you could build in for future use to "jump" your bus from a 12 volt battery, which is obviously totally common compared to 24 volt battery sources.

My question is with the bus stored for a long time, where will you get air to power the starter?

Brian

Adarian · December 22, 2009, 07:28:21 PM

Quote from: bevans6 on December 22, 2009, 06:00:37 AM

My question is with the bus stored for a long time, where will you get air to power the starter?

Brian

The air tank gauge for the air starter system is showing 120 psi.
So plenty of air.

The primary and secondary tank gauges are showing 0 psi.

Hartley · December 23, 2009, 08:14:39 AM

There should be a 24 volt buss-bar in the rear junction control panel
that you could hook a 24 volt supply to and get some charge/power into
the batteries. On Most FLX Metro's, Open the panel and look for a buss-bar
(maybe the vertical one? ).

The start solenoid only needs a couple of amps to operate.

Adarian · December 23, 2009, 08:17:18 AM

Quote from: DrDave-Reloaded on December 23, 2009, 08:14:39 AM
There should be a 24 volt buss-bar in the rear junction control panel
that you could hook a 24 volt supply to and get some charge/power into
the batteries. On Most FLX Metro's, Open the panel and look for a buss-bar
(maybe the vertical one? ).

The start solenoid only needs a couple of amps to operate.

Thanks, I know which one you are talking about.

Adarian · January 03, 2010, 04:41:37 PM

Got it started. Got it moved.
Used two lawn and garden type batteries connected in series.
Used the positive cable going to the alternator and the negative cable going to the engine block ground to complete the circuit.
I disconnected the jump batteries as soon as the engine started.
Thanks