Mercedes Benz O305/7 starting issue

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BembokaO305
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Joined: Tue Jul 21, 2020 11:34 pm

Mercedes Benz O305/7 starting issue

Post by BembokaO305 »

Hi all, I'm trying to move an old MB305 for a friend and it refuses to turn over. We have put two good batteries in it, pushed in the key and pushed the start button. The centre relay/solenoid clicks (quite audible) but nothing else. Is there any other master kill switch that may be the problem? It was running okay about 12 months ago apparently. The park brake is engaged and gear shift is in neutral. Are there any other safety checks which might be stopping it? Thanks Paul, Bemboka NSW

BembokaO305
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Joined: Tue Jul 21, 2020 11:34 pm

Re: Mercedes Benz O305/7 starting issue

Post by BembokaO305 »

And a related question, do these buses use a positive earth electrical system? I have connected the two batteries to the bus according to the colour of the terminals .... ie red connected to positive end of battery. But this cable seems to go straight to a large solenoid and from that solenoid the other cable is attached to the chassis .... thoughts?

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boronia
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Joined: Fri Mar 05, 2004 7:18 pm
Favourite Vehicle: Fire engine; PD4107
Location: Sydney

Re: Mercedes Benz O305/7 starting issue

Post by boronia »

Check for a safety isolation switch on the engine hatch. Some buses won't start if this is open. or not closed properly.
The Sydney Classic and Antique Truck (and Bus) Show
On again June 2021
@ The Museum of Fire.

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Guy_Arab
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Favourite Vehicle: M.A.N Bus & Guy Arab
Location: Perth W.A.

Re: Mercedes Benz O305/7 starting issue

Post by Guy_Arab »

IF YOU REQUIRE A WIRING DATA CONTACT ME I SEND IT FREE
GUY ARAB tram1one@bigpond.com

BembokaO305
Posts: 0
Joined: Tue Jul 21, 2020 11:34 pm

Re: Mercedes Benz O305/7 starting issue

Post by BembokaO305 »

Thanks boronia, I'll check that out. Email sent Guy, thanks.

BembokaO305
Posts: 0
Joined: Tue Jul 21, 2020 11:34 pm

Re: Mercedes Benz O305/7 starting issue

Post by BembokaO305 »

Anyone on here currently driving one of these around? Especially if it's not too modified... I would love to able to talk through the details with you.

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