Will not start and Allison transmission key pad does not light on start

[Mike Canter]

Find that butt connector and replace it.

[mel s]

Originally Posted by Jeff753

Anyone have a part number for the battery switch. Mine looks like this now and it's pretty old.

Since I'm having trouble I should probably have another one
I'm not at the coach to look what the part number is on the old ones. I have two switches. One for the 8D Chassis battery and one for the 440AH 4 - 6V House Bank

Jeff753
Try here: Products | Cole Hersee - Littelfuse

[walt2137]

Here is the ph no. And it a M 750 switch
Cole Hersee Company
20 Old Colony Avenue
Boston MA 02127-2467
617-268-2100

[Mike Canter]

The power to the Allison transmission ECU is wired direct and NOT through the battery disconnect switch or through the main battery cable. To check your currently installed battery cut off switch just turn it off and on and see if things turn on and off it the motorhome.

[Jeff753]

Originally Posted by Mike Canter

Find that butt connector and replace it.

I will do that and report back. Probably going to be Friday

[terry735001]

both ECM and TCM have wires for hot at all time then hot with key on

red hot at all time
pink hot when key is on

some RV makers love to have fun and run black and wight wring at that time black is not - this is what gets alot of guys if they go by cooler code

so keep it in mind the black can be + at times but you most of the time find that on TT and 5ers and older class A

good thing to do is all ways take pics

think back do you have you have any pics of the inside of the bay

[Jeff753]

Originally Posted by Mike Canter

Back in those years of Monaco motorhomes it is very common to loose power to the Allison ECU because of a butt connector located on the small wire going from the positive battery post directly to the transmission ECU. If you follow all the small wires going out of the battery box area you will find the connector. It is 2-3ft down the wire. Most likely when you had the batteries changed you disturbed it and caused the problem. Without power to the Allison transmission ECU the neutral safety switch will not let it start

Got rained out but 1)6 red wires and 6 white wires are wired directly to the battery (red on positive white on negative ) post. 2 are 7 amp, three are 10 amp and 1 has a 20 amp in line fuse. One of the 12 ga wires with a 10 amp fuse is in its own loom so I started with it Found a butt connector about two feet down. Checked and found voltage on both ends of the butt connector. Checked neutral safety relay and found no voltage across coil Took off all connections from chassis battery and jumped the red wire I was focusing on. Transmission display came on but then I could hear the level safety relay was clicking and flashing the display. Keep in mind at this time the chassis battery and the other 5 red leads were not connected. Rain came.

Next I am going to replace the wire from the butt connection to the battery even though voltage was metered on both ends. It seems that wire is suspect number 1 at this point as Mike suspected. At least I know which of the 6 wires is the ECM. Anyone has any idea what the others might be. I thought it might be things like co2 or propane connections but they were both on with the 6 reds disconnected. Will get back on it tomorrow. I can't really get under it to chase the wire out of the battery box. Is the other end of that red wire go to the ECM and where is the ECM located on the transmission housing or under the shifter?

[Mike Canter]

The Allison ECM is under the shift pad. One of the other smaller wires goes to the engine ECU and another one is the accessory wire to lights, dash, ignition switch. People have also said that the butt connector gets corroded inside. I think you are on the right track. It has to be something that was disturbed when you changed batteries

[Jeff753]

Originally Posted by Jeff753

Got rained out but 1)6 red wires and 6 white wires are wired directly to the battery (red on positive white on negative ) post. 2 are 7 amp, three are 10 amp and 1 has a 20 amp in line fuse. One of the 12 ga wires with a 10 amp fuse is in its own loom so I started with it Found a butt connector about two feet down. Checked and found voltage on both ends of the butt connector. Checked neutral safety relay and found no voltage across coil Took off all connections from chassis battery and jumped the red wire I was focusing on. Transmission display came on but then I could hear the level safety relay was clicking and flashing the display. Keep in mind at this time the chassis battery and the other 5 red leads were not connected. Rain came. Next I am going to replace the wire from the butt connection to the battery even though voltage was metered on both ends. It seems that wire is suspect number 1 at this point as Mike suspected. At least I know which of the 6 wires is the ECM. Anyone has any idea what the others might be. I thought it might be things like co2 or propane connections but they were both on with the 6 reds disconnected. Will get back on it tomorrow. I can't really get under it to chase the wire out of the battery box. Is the other end of that red wire go to the ECM and where is the ECM located on the transmission housing or under the shifter?

I cut out the butt splice on the wire I identified as feeding power from the chassis battery to the transmission ECM and put in a new piece of wire. Put it all back together and the transmission key pad lit up. Turned the key and started I'm a bit confused because I measured voltage on both sides of the butt connector before the repair. The connector looked okay but I will cut it open and check for corrosion. I suppose it could have just been removing all the battery wires and resetting them that fixed it too. Anyway, check that off the list for now. Thanks to all again for your help and suggestion. Special thanks to Mike!!

[Mike Canter]

That's great to hear. Congratulations. I said it my earlie post that it may look good but it's not. They get loose and corroded inside the connector and will work ok with no load and current flow but as soon as you put a load on the wire and get higher current flow it arcs I breaks the connection. This problem has been return to this forum ever since I joined and probably way before that.

[Jeff753]

Originally Posted by Mike Canter

That's great to hear. Congratulations. I said it my earlie post that it may look good but it's not. They get loose and corroded inside the connector and will work ok with no load and current flow but as soon as you put a load on the wire and get higher current flow it arcs I breaks the connection. This problem has been return to this forum ever since I joined and probably way before that.

I violated my rule of tearing into something away from home if I don't have to. After I started a few times we hit the road for Easter. On the way I noticed my LCD odometer was showing ERR1. I thought that's probably related to my non start/ECM issue also. I read you can unhook the CHASSIS ground for two minutes to clear the error. I tried it. Guess what happened? No transmission display nor start since it can't pass the neutral safety check to the relay. The gremlin is back!!! It must be the battery drawer There are 7 red wires wired directly to the positive side of the Chassis battery. 1 with a 20 amp in line fuse, 3 - 10 amp and 3- 7.5 amp fuses. You may recall Saturday I replaced one of the but connectors (10amp fuse) that I did determine would power the transmission display (by connecting that single red wire to the battery). Now with my non start again I pulled some more wire loom off and noticed the 20 amp fuse has a butt connector that has frayed wires and looks a bit suspect. It has continuity on both sides though may fail under load. I'm going to replace it tomorrow. Of course Mike told me there were two wires from the battery to the Allison boxes;(. I'm hoping the 20 amp is my problem. It's something to do with disturbing the batteries and making/breaking a contact.

I would like to know what these 7 separate fused direct leads to the chassis battery are though. They seem significant to successful operation

I will call Monaco Monday. Maybe they know. What would the 20 amp be? Dash?? I have never noticed these wires in the wiring diagram I have.

[Jeff753]

Originally Posted by Statgeek

if wiggling the wiring makes things work, i wouldn't be happy until i removed and replaced every wire in your battery bay to make sure they are TIGHT. you could easily fry your new lifeline batteries with loose connections...even if you wiggle it enough to start the coach.

I share your concern!! One problem is I can only replace 1) butt connectors and short wire and 2) battery connections. I'm doing that next. I had a suspicion I didn't really fix the problem when it started a few times Saturday.

[Jeff753]

Originally Posted by Jeff753

I violated my rule of tearing into something away from home if I don't have to. After I started a few times we hit the road for Easter. On the way I noticed my LCD odometer was showing ERR1. I thought that's probably related to my non start/ECM issue also. I read you can unhook the CHASSIS ground for two minutes to clear the error. I tried it. Guess what happened? No transmission display nor start since it can't pass the neutral safety check to the relay. The gremlin is back!!! It must be the battery drawer There are 7 red wires wired directly to the positive side of the Chassis battery. 1 with a 20 amp in line fuse, 3 - 10 amp and 3- 7.5 amp fuses. You may recall Saturday I replaced one of the but connectors (10amp fuse) that I did determine would power the transmission display (by connecting that single red wire to the battery). Now with my non start again I pulled some more wire loom off and noticed the 20 amp fuse has a butt connector that has frayed wires and looks a bit suspect. It has continuity on both sides though may fail under load. I'm going to replace it tomorrow. Of course Mike told me there were two wires from the battery to the Allison boxes;(. I'm hoping the 20 amp is my problem. It's something to do with disturbing the batteries and making/breaking a contact. I would like to know what these 7 separate fused direct leads to the chassis battery are though. They seem significant to successful operation I will call Monaco Monday. Maybe they know. What would the 20 amp be? Dash?? I have never noticed these wires in the wiring diagram I have.

Fixed again. Sheared the thin 5/16 ring connection from the 10 amp Allison wire. I used a backing washer between the last ring terminal and the nut this time.

I did find out the 20 amp direct wire to the chassis battery is from the RV30D solar charge controller. This pair has voltage when it's disconnected from the battery because it's a charge feed from the 90 watt panel. Need to cover the panel to stop the voltage prior to working on the wires.

I still have the ERR1 error on the odometer but I'll work on that when I'm back at home base. I'll run a direct ground wire. If it's a Beede LCD Odometer I have a lead on getting a new one.

[HJLowell]

Originally Posted by Mike Canter

Back in those years of Monaco motorhomes it is very common to loose power to the Allison ECU because of a butt connector located on the small wire going from the positive battery post directly to the transmission ECU. If you follow all the small wires going out of the battery box area you will find the connector. It is 2-3ft down the wire. Most likely when you had the batteries changed you disturbed it and caused the problem. Without power to the Allison transmission ECU the neutral safety switch will not let it start

Thanks much