I tried to sort this out, but I need reinforcements. Bus won't start...ughhh

[BlackJohn]

What is the door light even on for when you are trying to start the bus? Door open or what? Is the switch bad that turns that light on, if it's even separate from all else.

You say sometimes the buzzer doesn't buzz. Under what conditions do this happen?
Is the air drier at those times than when the buzzer buzzes. That's moisture creating paths for current to flow when and where it shouldn't.

What changes did you make removing the hatches? Were they alarmed with switches on each frame for the warning buzzer.
Tell us something here other than you have tried and no start exists.

[RC000E]

Originally Posted by turf

never trust what you think is a good battery or battery connections.

more info please. include voltage from a meter.

Bus has solid 12v all through it. I'd point out a battery can have 12v but fail under load. Static 12v doesn't confirm much from a load perspective, but to be clear, the batteries are very good, and have full 12v. To be clear, this is all via meter...I only test with a Fluke meter that is very high quality.

I've done some additional testing at the panel, as indicated in next post.

Thanks so far.

[RC000E]

Originally Posted by BlackJohn

What is the door light even on for when you are trying to start the bus? Door open or what? Is the switch bad that turns that light on, if it's even separate from all else.

You say sometimes the buzzer doesn't buzz. Under what conditions do this happen?
Is the air drier at those times than when the buzzer buzzes. That's moisture creating paths for current to flow when and where it shouldn't.

What changes did you make removing the hatches? Were they alarmed with switches on each frame for the warning buzzer.
Tell us something here other than you have tried and no start exists.

No collapsible position switches on the roof hatch like seen on the back window, rear engine hatch, etc but they do have a voltage and ground wire. Of course, since the bus ran before the sign, roof hatch and front turn signal removal I want to blame these sources, but none have position switches.


Here is what I've found today. In the side panel, the two main solenoids are functioning normally. They make connection with key in "on" position and send power through the two copper bus bars. When I hit "start" the solenoid on the right in the pic disconnects and the lead wire to it loses 12v. I clipped that wire, then jumpered 12v to manually stimulate the solenoid, but in the "start" position the starter didn't engage still.

So, I assume the interrupt is somewhere else, or is this function normal? Anyone have a bus to compare? This is why in the "run" position all interior lights and accessories turn off, which I think is likely normal function to allow all battery power to go to starting the bus in the "start" position.

Next step, all I can think is start at the starter, and see if manually stimulating the solenoid makes the starter turn, then start fishing through the bus to find where the issue may be.

The guy who helped me unbolt the seats may have pulled something underneath? I can't imagine there is much exposed under there. The wires probably are in a protected bundle.

still lookin...

[turf]

12v is a dead battery, jus saying.

your battery cable should go straight to the solenoid and starter. its not hard to trace. they are the big fat ones. if you jump the solenoid and starter doesnt move. its the starter or the battery.

make sure you are neutral and tires chocked. underneath a bus is no place to be when it moves

[turf]

the solenoids in that panel are not your start solenoid. you may be pre heating a fuel grid or who knows what. the starter circuit is very basic. a big fat wire goes from the battery to the solenoid and then to the starter. a third wire triggers the solenoid. if the starter is grounded, and juice is applied, it will turn.

[BlackJohn]

Here is what I've found today. In the side panel, the two main solenoids are functioning normally. They make connection with key in "on" position and send power through the two copper bus bars. When I hit "start" the solenoid on the right in the pic disconnects and the lead wire to it loses 12v. I clipped that wire, then jumpered 12v to manually stimulate the solenoid, but in the "start" position the starter didn't engage still.

That too me seems as normal. The key is turned to "on" which disconnects everything from "Accessory" and that solenoid drops out of the circuit.
When the key is still on the other solenoid is powered and a further turn of the key to "Start" energizes the starter relay which then feeds the starter solenoid, which allows cranking of the starter motor.

This is not the time to clip any wires and try to feed from another source as you have done.
I do feel worried you will hurt yourself bad with that approach if under the bus doing that. It'll bite you!

[BlackJohn]

No collapsible position switches on the roof hatch like seen on the back window, rear engine hatch, etc but they do have a voltage and ground wire.

What does this mean? No factory switches? Or, wiring but no factory switches?

You'll have to make yourself clearer in what you say or I can't help you.

[EastCoastCB]

The roof hatch has a switch, just not the same switch the side and rear doors would have.

[turf]

your fluke meter should give you readings.

12.0v is dead

13.5 volts is pretty well charged.

you keep saying 12.... so...its dead!!

its a rear engine bus? are the switches in the right position on the remote?

[BlackJohn]

Originally Posted by turf

your fluke meter should give you readings.

12.0v is dead

13.5 volts is pretty well charged.

you keep saying 12.... so...its dead!!

its a rear engine bus? are the switches in the right position on the remote?

I agree with turf, 12 v is dead. Might start a warmed up engine but not one that has been sitting and needs lots of juice to turn the starter and make heat for the fuel mixture to ignite and stay running.

[BlackJohn]

I understand his bus isn't like what you explain CB. No answer yet from him.

[BlackJohn]

Originally Posted by RC000E

Currently buzzer isn't going off upon retry...no buzzers.

Key on initiates 4 clicks in succession, each progressively closer to the rear of the bus and it cycles that sequence 2 x in a row (8 clicks total). I recall this being normal when it ran. When I then turn to start, I hear a solenoid click in the side panel, but no start.

"When I then turn to start, I hear a solenoid click in the side panel, but no start."

The click you hear when you turn to start is I hope, the fuel solenoid energizing. Have you checked that ? Oh wait, you still haven't clarified if it even turns over.

[RC000E]

Originally Posted by BlackJohn

No collapsible position switches on the roof hatch like seen on the back window, rear engine hatch, etc but they do have a voltage and ground wire.

What does this mean? No factory switches? Or, wiring but no factory switches?

You'll have to make yourself clearer in what you say or I can't help you.

I mean that the roof hatch area has no indicated microswitch or collapsible switch visible. Upon removal there is one white wire and one black, indicating there were 2 wires going to each roof hatch. In the "on" position they have 12v, one ground, on power.

[RC000E]

Originally Posted by BlackJohn

"When I then turn to start, I hear a solenoid click in the side panel, but no start."

The click you hear when you turn to start is I hope, the fuel solenoid energizing. Have you checked that ? Oh wait, you still haven't clarified if it even turns over.

The solenoid that clicks is for the accessory panel...warning lights, interior lights, etc. I've determined this to be "normal" via the manual. It allows all battery power to be used for the start cycle.

Does not turn over whatsoever.

I need to test from the back but, unfortunately backed the bus to a wall pretty tight and now in a bit of a pickle on that...lol.

[RC000E]

Originally Posted by turf

12v is a dead battery, jus saying.

your battery cable should go straight to the solenoid and starter. its not hard to trace. they are the big fat ones. if you jump the solenoid and starter doesnt move. its the starter or the battery.

make sure you are neutral and tires chocked. underneath a bus is no place to be when it moves

Originally Posted by turf

the solenoids in that panel are not your start solenoid. you may be pre heating a fuel grid or who knows what. the starter circuit is very basic. a big fat wire goes from the battery to the solenoid and then to the starter. a third wire triggers the solenoid. if the starter is grounded, and juice is applied, it will turn.

Originally Posted by turf

your fluke meter should give you readings.

12.0v is dead

13.5 volts is pretty well charged.

you keep saying 12.... so...its dead!!

its a rear engine bus? are the switches in the right position on the remote?

12.5-12.6v in static, non running state is a fully charged automotive battery. Under running conditions you see higher because the alternator outputs a charge voltage. A RUNNING engine with a charging battery outputs the voltage you're quoting. I'm also quite aware the starter solenoid is on the starter. I've built forced induction cars for 20 years and wired full fuel injection systems from scratch, as well as built standalone fuel management systems from scratch, down to soldering every 5pin high side switch, resistor and diode. Just to be clear.

These batteries started the bus confidently prior to removal of seats, sign, etc. The terminals are 100% clean, the connections are completely clean. In addition, I've maintenance charged the batteries and even put on a full start 200amp connection via a plug in battery charger.

It is 100%, not the batteries and not the system voltage.

[RC000E]

At this stage I've opened the rear electrical modular panel. I've also located what I feel are pretty accurate electrical diagrams for this bus, by searching and the user Porkchopsandwiches posted them.

I can't start it via the rear modular panel start switch, so it appears it's neutral switch (VIM) or interlock related. What I'm attempting to do is just energize the starter relay.

I'd like to stimulate the starter solenoid, but getting back there is a bit of a mother at this moment. I may have to air up the tank and release the parking brake and pull the bus forward tomorrow.

Seems my best course is to work starter forward.

I would love to know why the roof hatches have wires going to them. The hatches are transpec roof hatches. One white wire, one black. No diagrams I've found point to what the wires were for, and I don't recall there being a light on them. Just a red handle. Clearly the wires served a purpose that I'd like to eliminate.

[EastCoastCB]

Originally Posted by RC000E

At this stage I've opened the rear electrical modular panel. I've also located what I feel are pretty accurate electrical diagrams for this bus, by searching and the user Porkchopsandwiches posted them.

I can't start it via the rear modular panel start switch, so it appears it's neutral switch (VIM) or interlock related. What I'm attempting to do is just energize the starter relay.

I'd like to stimulate the starter solenoid, but getting back there is a bit of a mother at this moment. I may have to air up the tank and release the parking brake and pull the bus forward tomorrow.

Seems my best course is to work starter forward.

I would love to know why the roof hatches have wires going to them. The hatches are transpec roof hatches. One white wire, one black. No diagrams I've found point to what the wires were for, and I don't recall there being a light on them. Just a red handle. Clearly the wires served a purpose that I'd like to eliminate.

They sound a buzzer when the hatch isn't fully closed and the bus is running or in the on position.

[DoubleO7]

Is it a handicapper bus?

[superdave]

when you start it from the rear you need to have the key turned on and the engine door button pushed in for it to work.

[turf]

don't air your bus up in an attempt to start it! it will only roll away. lack of air is not stopping the starter.

it didn't break while it sat there. your starter didn't go bad, your solenoid didnt go bad since you havent used them.

it something simple you have overlooked. or damage that you caused

trans in neutral
close doors or child counter
low voltage

with all the race cars experience in the world, you sound pretty green with diesel buses.