Hello,
Recently I bought a 1982 MCI MC9 with a 6v92 and an automatic transmission.
We drove it 100 miles home without any issues whatsoever.
We parked it, and came back to it 3 days later to try and move the bus and it would not start.
Engine doesn't even try to turn over. Step chime lights are on, bus is in neutral, but pressing the starter button (front or rear) gets you nothing. Just a single click from the engine compartment. All of the lights, gauges, and accessories work, but the bus just will not crank.
We originally thought it might be the batteries, as the ones in the bus were over 14 years old.
We replaced both 8D batteries with a brand new set and still have the same issue.
Any insight on what to check next? We're pretty handy, but pretty stumped on what it could be, since it was fine a week ago and just randomly stopped cranking without any symptoms beforehand.
1st check the switches in the rear and see if it's accidentally been put on rear start.
2nd while at those switches put it on rear and hit the start switch (it will be the spring loaded toggle switch) if it starts from the rear then either a problem up front, somewhere in between or it was on rear.
Also try moving the shifter while pushing the button, and also make sure the brake button is UP.
Yes I know the brake button is supposed to pop up whenever it gets below 60 psi but I can tell you I have seen many times they didn't!
If these don't work we'll need to start checking some other things.
Does it have a wheelchair lift or door?
Any windows been opened and not shut good?
;D BK ;D
My MC8 has experienced a couple on-strike situations. Like you, push start and zero, no noise in my case. Check the gear selector, yes to in neutral, parking brake knob up, lights/buzzers ok. Go to back to start and one time it started there, second time it did not. Went back to front and it then started right up.
Since it has happened only a couple random times, it is on the quirky list for now. Very interested to follow this one and learn that circuit and how it goes foul.
Probably gonna be dirty, loose or corroded connections somewhere along the way. Could be at the dash switches, could be the rear control box, could be the front junction box, could be the rear junction box, could be in the battery box, could be the connections on the starter solenoid, could be THE solenoid! Could be... Could be.... could be ......
;D BK ;D
The rear switches are in the correct position, brake is all the way up. I have tried moving the shifter while pressing the button and get nothing still.
I'm really stumped on how it was fine one day and we get absolutely nothing the next.
Starter would be my guess. At least to test. Get someone to push start button and determine the source of the noise.
Since you have new batteries, check all of the connections for corrosion. Check the voltage at the batteries, and then at every step between them and the starter. It could be a bad cable with internal corrosion or a bad ground connection.
New batteries doesn't mean they are charged...
What's your voltage?
Happy coaching!
Buswarrior
Go to NAPA or same and get a remote starter button Heavy duty and hook it to your starter has clips. See if it starts that way if it does it might be your neutral switch on the transmission if it is an automatic. Also in the rear bulkhead driver side electrical box there are two Ice cube fuses. Pull those and put them back in a few times. Then try it again. ONe of them is your neutral switch fuse and can be replace with your heat ice cube fuse up in the left front electrical box to see if that fixes it then if it does just get a new one at any big electrical supply like Platt.
Also, toggle the rear start switches. I've seen them be dirty from non use also.
Another quick test would be to use a jumper wire from the main 24V positive post on the starter and touch it to the small wire on the solenoid to see if it starts!
:D BK :D
By pass the fuel pressure switch mounted on the filter
Recheck your interlock requirements. Might be something not so obvious like the door having to be closed.
Jim
Dang, so many great tips - we ran him off.
putting a can of contact cleaner on the shopping list. lol
Still here! Yesterday was busy pulling the seats!
Unfortunately the bus is about 30 minutes from my house so I plan on trying all these suggestions this weekend when I've got a bit of free time!
Okay so little bit of an update. I went and bought a remote starter switch and hooked it up to these two spots on the solenoid. I hit the button and she fired right up without any sort of hesitation.
I believe this means I've got an issue with the neutral safety switch right? At least I know I can manually fire her up if need be.
Kyle,
The best advice is to get familiar with the original FSM (Factory Service Manual). It is the bible as to how the majority of the bus works and is wired. Any subsequent alterations or factory manual updates will be missing. Still, 99% overall is accurate.
There is a large section on wiring, do not have it in front of me. It could be starting section. Either way, become familiar with the components on the diagrams, looking for the starter, start button, rear remote start box, and gear selector. Since it starts it gets power and starter is working, so problem is in the start circuit.
Forgot if you tried starting using both switches, the rear one on the left side of the engine compartment and the driver dash.
You also need to invest in a decent multimeter, preferably a clamp meter for reading current. A circuit chaser is had at HF. That will be enough to start looking for a break in the connection.
Not always the neutral switch,the fuel pressure sensor will not let the starter engage from the front or rear without over riding it ,the MCI 9 is easy to trouble shoot just follow the wire from the "S" terminal on the starter it should be hot when trying to start
Well, unfortunately things took a turn south this weekend.
We had to move the bus, it started up fine but wouldn't shut down without shutting off the disconnect at the batteries. As soon as you'd flip it back on the bus would immediately start back up.
Didn't catch it in time, but it looks like the starter was staying engaged and unfortunately I'm pretty sure it smoked itself yesterday. Going to try to replace the solenoid, but there's a good chance that the starter itself is cooked.