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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: mwf on November 29, 2007, 04:57:06 PM

Title: selonoid or relay
Post by: mwf on November 29, 2007, 04:57:06 PM
As I am sure all can tell, I am a novice at this.  The relay for the starter in the rear electric panel is bad.  I think it would be 24 v.  Any one know?    1988 MCI 96A8     DD 8V92.

Also looking for a driverside window with the toll window  frame and all if some one has done a conversion and has one.

Thanks
Title: Re: selonoid or relay
Post by: Sammy on November 29, 2007, 05:30:16 PM
Make sure bus is in neutral and parking brake is applied.
Neutral safety switch is part of that circuit - will interrupt starter circuit to prevent starting in gear.
MUST be in Neutral for relay to energize.

Put a voltmeter on the small stud of relay, have an assist try to start the bus for you - read voltage.
You also have a rear start switch in the engine compartment - make sure it's in the proper position.
Good luck  8)
Title: Re: selonoid or relay
Post by: mwf on November 29, 2007, 07:04:19 PM
Thanks sammy.
Have had to use the rear start for a couple of weeks, but last week just before leaving for Miami that switch would not work.  Bus was in neutral, but have had to jump the relay to start the bus.  Plan to pull off relay this weekend and pick one up, will have to check the volts comming into the relay.
Title: Re: selonoid or relay
Post by: JackConrad on November 30, 2007, 04:40:00 AM
If it is the same as our MC-8, it will be 24 volt.  Jack
Title: Re: selonoid or relay
Post by: Stan on November 30, 2007, 05:27:12 AM
Jumping the relay contacts is only valid if the relay closes but the contacts do not make. Putting an external voltage to the relay coil is defeating a built-in safety system. Study your start system wiring diagram and locate all the switches that are in the line to the coil on both the hot side and ground side. IIRC the fuel pressure switch is in the ground side on earlier MCIs. A cheap voltmeter could isolate your problem in minutes With the starter switch engaged, you should have full voltage (26? volts) on the relay coil hot terminal and zero volts on the ground terminal  referenced to a good ground. If you don't have that, locate the open switch.

Defeating engine protection and bus safety systems is a bad habit.
Title: Re: selonoid or relay
Post by: gumpy on November 30, 2007, 06:17:41 AM
I have the driver window from my MC9. Not sure if it's the same for the A3. It's yours if you want it. Located in MN.