SharkBus -- Power to Ignition question

[SharkBus]

Hello Skoolie enthusiasts ---

I have a 1987 School bus with a 366 big block GMC engine.

It was very lightly used, as it was a church bus -- so it is in excellent condition.

Before I purchased it, it started no problem. We left it sitting in the yard for a few months and after hooking up the new battery ( which reads 12v ) we have absolutely no power.

Lights, fans, etc... nothing has power.
The engine won't even turn over.


Has anyone encountered an issue like this before, or have any clues as how to resolve it?

Thank you so much.

Sharkbus

 

[Tango-SKO]

Check battery level...if still hot enough to crank...check the connections, especially ground. They can corrode pretty quickly while sitting.

 

[Jolly Roger-SKO]

Like Tango said check the main ground wire connections. 12v should run the lights until but it won't start the engine. Need to average 13-14 to start.
If you have 12v checking the battery itself( not just relying on the guage) I would start looking and listening for the solenoids to click,thump,engage whatever you want to call it.
I have seperate solenoids for starting and auxiliary power/lighting check that you have power to them and leaving them

 

[cowlitzcoach]

This might sound dumb but I hope you took the plastic covers off of the battery posts before you put the battery cables on.

After taking the plastic covers off, did you take a battery post cleaner and shine up the posts? The protective covering on the posts can make it hard to make a good connection.

Did you clean the ends of the battery cables to make the insides look nice and shiny? Shiny will make a good connection. Not shiny not so good.

And lastly, did you get the battery cables tightened down so they don't move on the posts? Tight works well. Loose will require greater amperage to cross the gap to make a connection.

Finally, check to make sure the ignition switch is working correctly. We had one bus that had a small leak between the cowl and the bus body that allowed a little leak to drip down onto the ignition switch. Over time it turned the switch green and got to the point where nothing worked.

Good luck and let us know how you solved your problem.

 

[Roadrunner-SKO]

Also, check the ground cable where it connects to the bus itself. You may have to remove that end and make sure you are getting a good ground. If that is ok check where the positive cable connects, probably the starter to make sure you have a good connection there too. Since nothing at all works it sounds like a battery cable connection somewhere. I hope this helps.

 

[roach711]

Some buses have a battery disconnect switch. Mine is beside the driver's seat.

 

[SharkBus]

Thanks everyone so much for your detailed responses--- it must be something to do with the wiring, I will look at it next week and let you all know what the problem was and how I resolved it.

Thanks again

 

[SharkBus]

Hey everyone--- just to keep you in the know---- I got it up and running!!!
The only problem is that I have no idea what made it start.
We unbolted the fuse box under the dash (the bolts go through to under the hood) and then we tightened it back up again, so I think that a wire must have been loose and was re-situated properly in the process.

We also cleaned up the ground cable because it was rusted, and we cleaned up the spot where it attached to the chassis . This didnt help until we played around with the wires by the fuse box.

So many little delicate wires. Thanks again for all the ideas in tackling this.

 

[Robin97396]

As usual, it usually comes down to a little elbow grease.

 

[engelstad]

I have kind of similar symptoms... The bus has been used every week or so for the last 6 months, and yesterday I drove it, then changed the oil, then drove it again this morning, and then turned it back on to check the trany oil level using the allison pushbutton display thing, and then turned it off. I then changed the trany oil, and went to start it, and nothing (no beeping ignition sound, nothing when trying to start it)... I tried to jump start it, and even when the jumping car rev'd to 4k rpms, at least it had the beeping ignition noise, but when I turned the key to start the bus, it just did the clicking every half-second or so, but no turn over, etc.

I tried looking at the ignition area, and I don't see anything obvious, though I'm not sure exactly what to look for. The fact that when there is jumping car connected to the bus battery, it makes me think the ignition is OK. But, the bus battery has been fine, and whenever in the past I drained it too much, it would easily jump using the same car I'm trying to use now.

The only work I've done in the last day is replace the engine oil and the trany oil, and I'm not understanding how these are related, etc. Any ideas or suggestions?

 

[Docsgsxr]

Automotive batteries don't normally have the CCA's needed to turn those big flywheels. Also, you can burn up your alternator that way as well.

Clicks mean dead batteries, or bad connections. I would try removing all wires 1 at a time and cleaning and re attaching them. Coat the ends on the terminals with some petroleum jelly for corrosive resistance.

If none of that works,

100 Amp 6/12V Battery Load Tester

Go get one of these and test your battery(ies)

 

[engelstad]

Thanks Docsgsxr... I was in the final stages of installing a battery isolator between the bus starting battery and the solar battery array (eight 6V batteries, connected to form 12V battery array of ~840Ah).

This morning when I had the starting issue, the battery isolator was not installed. The battery isolator is installed, and when I do the override, which connect the solar battery array to the bus starting battery, the bus starts right up.

But, when I disconnect the override, the bus dies immediately. I would have figured that even if the bus had dead battery, the alternator would be enough to keep the bus running, right? What do you think is my issue? Thx!

 

[Robin97396]

What Doc said.

Yeah, when using your car to start another vehicle leave the ignition turned off and jump the other vehicle using just the battery power. Not only can you damage your alternator the way you're using it, but you can also do a royal job on the computer in your car. That's really hard on a car alternator to do that. I usually estimate they are good for about 4 to 10 jump starts before going bad.

I hate to say it but if your battery terminals are already clean, check your ground wire to the frame. Disconnect it and use some sandpaper to clean the contact area on the frame and on the terminal end, bolt it back on tightly then smear some grease on it.

But then since we're far away it's kind of hard to judge. If your battery is good, it's got to be a connection. They get corroded on older vehicles.

 

[Robin97396]

It sounds like an electric fuel pump is probably cutting out and starving the engine when you disconnect the solar array.

 

[Docsgsxr]

Thanks Docsgsxr... I was in the final stages of installing a battery isolator between the bus starting battery and the solar battery array (eight 6V batteries, connected to form 12V battery array of ~840Ah).

This morning when I had the starting issue, the battery isolator was not installed. The battery isolator is installed, and when I do the override, which connect the solar battery array to the bus starting battery, the bus starts right up.

But, when I disconnect the override, the bus dies immediately. I would have figured that even if the bus had dead battery, the alternator would be enough to keep the bus running, right? What do you think is my issue? Thx!

So let me get this straight, when the coach batteries are connected to the start batteries it starts and runs, engage the isolator and it dies?? Sounds like you have bad starting battery issues my friend.

 

[Docsgsxr]

Engelstad, check your pm's.