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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Frank @ TX on August 29, 2010, 03:57:53 PM

Title: Starting Motor Problems
Post by: Frank @ TX on August 29, 2010, 03:57:53 PM
Hi
I have an MCI-9 , 1984 , 6V92.
Every once in a while I start the engine between trips to charge the bats and warm up things.
Well , it didn't crank over this time.
The bats are full , no corrosion at the connections anywhere.
I tryed to jump the starting motor at the terminals on the back of the solenoid.
The motors spins but the gear isn't thrown in to the fly wheel.
Is there another connection on the solenoid that is the right one to use?
I did tap on the motor and solenoid a few times to see if that would free things , but no help.
Seems to me that there should be a connection on the solenoid that throws the gear in first and starts the motor at that time.
Any help would be appreciated.
Frank
Title: Re: Starting Motor Problems
Post by: luvrbus on August 29, 2010, 04:04:33 PM
The small wire on the solenoid engages the bendix drive, jump from the battery cable on the bendix to that terminal that should do the trick
Title: Re: Starting Motor Problems
Post by: Frank @ TX on August 29, 2010, 04:12:23 PM
Hi , I'll look around for a smaller wire.
I touched a small jumper between the two BIG terminals and all that happend is the motor ran.
It seems that there should be a smaller wire terminal on the solenoid but didn't find it.
I'll look again tomorrow.
Thanks
Frank
Title: Re: Starting Motor Problems
Post by: luvrbus on August 29, 2010, 04:20:58 PM
Frank, you should have 2 small wires on the starter solenoid at the bottom for power and one for the starter button

good luck
Title: Re: Starting Motor Problems
Post by: Frank @ TX on August 29, 2010, 04:39:40 PM
Hi luvurbus,
I just went out , I see one smaller wire coming from the bottom of the solenoid to the big terminal at the motor end.
AND I see an empty terminal screw between the big terminals at the back of the solenoid but no wire coming from it.
This smaller terminal screw is about a #8 or #10 screw. but I don't see a wire that may have fallen off.
I've got the neighbors cats sometime living in the engine area , they could have knocked it off.
But right now I can't see a loose wire at all in that area.
I'll look again tomorrow when it's brighter.
Thank you very much luvurbus.
Title: Re: Starting Motor Problems
Post by: luvrbus on August 29, 2010, 06:01:11 PM
Frank, depending on the way your bus is wired you could have just one wire

good luck
Title: Re: Starting Motor Problems
Post by: steve wardwell on August 29, 2010, 06:54:32 PM
is it possable the rear engine start switch is in rear start mode?  forgive me if this is too obviously wrong.............s...............
Title: Re: Starting Motor Problems
Post by: RickB on August 30, 2010, 10:50:54 AM
Check all of your grounds
Title: Re: Starting Motor Problems
Post by: txjeff on August 30, 2010, 11:23:43 AM
Dont ask how I know this, but if its a automatic transmission make sure its in neutral. ;D

Jeff
Title: Re: Starting Motor Problems
Post by: Jriddle on August 30, 2010, 01:40:33 PM
Might try grounding the terminals on the fuel pressure switch. I had to go through this one and the rear start switch and the transmition neutral switch. I am not sure how many more I will learn about. Keep us posted even it it is embarrassing. We all learn from others pain. http://www.busconversions.com/bbs/index.php?topic=14563.0 (http://www.busconversions.com/bbs/index.php?topic=14563.0)
John
Title: Re: Starting Motor Problems
Post by: Frank @ TX on August 30, 2010, 01:46:11 PM
Hi,
I could jump the starter and the engine starts good.
The front start control and the rear start control will not run the starter.
By jumping the starter I got the warm up cycle I needed.
There must be a lose wire some where that I'll have to find.
I don't like ( safety ) jumping the starter.

Might be a coincidence but the fast idle system stopped working.
The small air cylinder did not extend toward the linkage.
Very strange to have two problems at the same time , maybe they are related somehow.
Still Working at It
Frank
Title: Re: Starting Motor Problems
Post by: Len Silva on August 30, 2010, 02:14:33 PM
That sounds like it might be the neutral safety switch.
Title: Re: Starting Motor Problems
Post by: robertglines1 on August 30, 2010, 05:20:31 PM
ck see if you have power thru the ford type selonoid feeding the ign switch and fast idle..had one go bad once..on mci 8  Bob
Title: Re: Starting Motor Problems
Post by: Frank @ TX on August 31, 2010, 06:12:43 PM
THANKS for all your help
The culprit was the relay in the back electrical right above the muffler.  ( MC9 )
The relay is an eight pin octo type.
Thru it goes the neutral switch and the fast idle.
Both the neutral switch and the fast idle use the relay because of different systems.
Of course you can start the engine while in gear
AND
If you're in fast idle and try to put it in gear the fast idle drops out.
I just love all the safety systems but it takes awhile to find the culprit when there is a problem.
Thanks to all that helped
Frank