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unimo55

No Power To Allison Panel

8 posts in this topic

Monaco Coach Cheetah Safari.

I have no power to the Allison Transmission control panel, and when the engine start key is turned to 'start' nothing happens and there is no dimmng of the lights in the instrument panel. The electrical bay on the left side of the vehicle at the front does not contain any fuses marked 'Transmission' I am not sure whether I am doing the right things with the alarm/immobilizer.

Does anyone know whether these vehicles would have been fitted with immobilisers working through the transmission's start inhibitor? Or where the Allison ECU gets its power supply from?

This vehicle has been parked for 2 years, connected to shorepower and I started the engine about 6 weeks ago but there was no charge showing. Investigation revealed a seized (frozen) alternator and broken drive belt, which was renewed and the alternator overhauled. Now I can't start it!

Thanks

Stefan

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Hi Stefan,

Welcome to FMCA !!

Could you post the year of your coach and transmission model for the group?

When you mention not able to start, do you mean the starter will not engage ?

How is the battery charge? and did the battery cables get reconnected properly?

Rich.

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Does anything else that only works with ignition on not work-- dash HVAC fan for example?

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Had this problem with my Dynasty. It was a solenoid.

There are two in the electrical panel in front of the front left wheel. Get a circuit tester and find a ground. With the key on check both sides if each solenoid. you should have 12 volts on each side. If not then the solenoid is bad. When I found this I jumped across the solenoid with jumper cables til I got home.

Herman

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Actually, a safer way to temporarily work around a bad ignition solenoid is to label all the wires on one large lug, then move them to the other large lug. Now the solenoid is effectively bypassed.

The advantage is that you don't have a high amp hot jumper cable that could short to ground and/or jump off, turning off the engine/transmission.

Be sure to return the wires to their original position after stopping for the night.

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Hi Stefan,

Welcome to FMCA !!

Could you post the year of your coach and transmission model for the group?

When you mention not able to start, do you mean the starter will not engage ?

How is the battery charge? and did the battery cables get reconnected properly?

Rich.

Hi Rich,

Thanks for your response. When the key is turned to the start position, the starter does not engage and there is no feed being switched to the starter contactor, as there is no voltage drop and the panel lights such as the 'low air pressure' and the gauges do not dim or fluctuate. The battery charge state is good, the batteries are connected correctly and I have tried it with jumper batteries connected. The voltmeter on the panel at the helm shows 13.5 volts with the ignition switched on and it does not show any less when the key is turned to 'start'. This is why I believe the starter is being inhibited either by the immobiliser or by the transmission having no power to the panel so that it doesn't know it is in Neutral.

Stefan

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Hi Stefan,

Welcome to FMCA !!

Could you post the year of your coach and transmission model for the group?

When you mention not able to start, do you mean the starter will not engage ?

How is the battery charge? and did the battery cables get reconnected properly?

Rich.

Sorry, I don't know the year of manufacture. It was registered in England in 2005 so before then. The Unit No. is 706806 Manufacturer I.D. M-38

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Stefan,

There is a possibility your coach has a fuse panel on the drivers side compartment under the drivers side window.

Open the compartment and see if there is a screwed on panel covering the fuse panel.

There is a main ignition fuse often 50 amp size, if the power step does not work. this is one of many of the items powered from this fuse. Also looks like there is a ignition relay on the panel. Might control the starter circuit.

I also have been thinking that the ignition switch might be the problem. you mentioned that when the ignition switch is in the run position all the circuits powered from the switch work in this position, if I'm reading things properly.

One way to test the starter circuit is to find the exciter supply voltage at the alternator and see if there is voltage there or not. If you have no power on that terminal, then look and see if that wire got grounded and that is also grounding the starter relay power. Should that happen then you could not start the engine.

One little wire in the wrong place and things do not work. You did get the starter repaired and replaced just before this issue came up !!!!!

Should you fine that the alternator energizer wire got grounded in error, then you might want to check the diode in that circuit ti see if it got damaged. Stranger things have happened.

NOTE ! The alternator exciter voltage and starter voltage are only present when the key is in the start position.

You could check out my Alternator issues photo gallery at this link.

http://community.fmca.com/gallery/album/265-alternator-problems/

Still looking for additional information.

The VIN number for your coach.

VIN number location.Try turning the front wheels hard left
and look on the outside of the right (passenger) side frame rail behind the
right front wheel.

With it we might be able to locate some additional information.

This link might be worth looking into.

http://www.monacointernationalrvclub.com/


Rich.

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