Engine does not start, transmission selector problem

Forum for both AC and DC electrical components. From engine alternator to dashboard, inverter to batteries, and everything electrical in-between.
geantbrun
Posts: 48
Joined: Fri Nov 01, 2019 12:52 pm

Engine does not start, transmission selector problem

Post by geantbrun »

Hi to everyone
I need your help again and now for a more serious problem than my microwave not working! We left yesterday for a week trip and at the first stop at a gas station I made a pause. When I tried to restart the engine, I heard this noise that I thought is characteristic of low battery. I suspected a more serious problem as it's not normal that batteries are low if alternator is doing its job right? Anyway, I called the assistance for a boost and the guy took a measure before the boost: 11.7A, not so low. The measure dropped to 9 when I started the engine (would it be a sign that starter is asking too much?). We finally get to the camping (with no pause this time!) and just before arriving, I noticed something strange: the "do no shift" warning light was on and the gear seemed to be stuck on 5th. At the front desk of the camping (engine still running), I could not shift to Neutral, nor to Reverse! Fortunately enough, they found me a pull through and we were to able to get to our site. I turned off the engine and when I went to turn off the pacbrake switch (close to bed) I could hear its buzzing sound that went on and off every second. Strange.

We're there now on our site with no possibility to move. When I tried to start the engine this morning, I get no noise at all. Before I call someone for a tow, I would like to know a little bit more what could be the problem. Alternator? Starter? Electrical connexions that are broken/corroded and that could explain the problems with the electronic transmission?

Any help from your part would be greatly appreciated, as usual
Regards,
Patrick
Safari Sahara '96
Transmission Allison 6sp
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: Engine does not start, transmission selector problem

Post by wolfe10 »

What is the voltage at your chassis battery now (engine not running)?

What was the voltage at your chassis battery with engine running?

You need to diagnose (or pay someone to do it) your battery and charging system.

BTW 11.7 VDC is a DEAD BATTERY.

And, yes, the Allison ECU operates on 12 VDC, so inadequate voltage will cause transmission symptoms as well.
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Engine does not start, transmission selector problem

Post by stuplich@ymail.com »

geantbrun wrote: Mon Jul 27, 2020 8:34 am Hi to everyone
I need your help again and now for a more serious problem than my microwave not working! We left yesterday for a week trip and at the first stop at a gas station I made a pause. When I tried to restart the engine, I heard this noise that I thought is characteristic of low battery. I suspected a more serious problem as it's not normal that batteries are low if alternator is doing its job right? Anyway, I called the assistance for a boost and the guy took a measure before the boost: 11.7A, not so low. The measure dropped to 9 when I started the engine (would it be a sign that starter is asking too much?). We finally get to the camping (with no pause this time!) and just before arriving, I noticed something strange: the "do no shift" warning light was on and the gear seemed to be stuck on 5th. At the front desk of the camping (engine still running), I could not shift to Neutral, nor to Reverse! Fortunately enough, they found me a pull through and we were to able to get to our site. I turned off the engine and when I went to turn off the pacbrake switch (close to bed) I could hear its buzzing sound that went on and off every second. Strange.

We're there now on our site with no possibility to move. When I tried to start the engine this morning, I get no noise at all. Before I call someone for a tow, I would like to know a little bit more what could be the problem. Alternator? Starter? Electrical connexions that are broken/corroded and that could explain the problems with the electronic transmission?

Any help from your part would be greatly appreciated, as usual
Regards,
Patrick
Safari Sahara '96
Transmission Allison 6sp
Patrick
I've had a similar DO NOT SHIFT condition twice in 150k miles.....
Both times it was caused by lack of, (or insufficient DC power to), the Allison VIM, (Vehicle Interface Module), from the chassis batteries.

In addition to verifying that your chasiss batteries are OK and fully charged, I suggest that you verify that each of the inline fuses, (in the 14 gauge wires connected to your chassis battery positive post), are OK...(not blown or corroded).
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
Robert K
Posts: 105
Joined: Mon Oct 28, 2019 2:27 am

Re: Engine does not start, transmission selector problem

Post by Robert K »

my do not shift light was caused by corroded butt connecters . They were in the wire looms on top of the ac condenser.

And yes low voltage will cause the do not shift light to come on
Bob
96 Serengeti 37'
3126 Cat
6 speed Allison
2011 jeep wrangler towd
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Engine does not start, transmission selector problem

Post by TDJohn »

Patrick,

Brett is right on the money, as he always is. As he stated, check the voltage of the engine batteries. If they are low, which I'm sure they will be, and assuming you are plugged into shore power, use a battery charger to charge the engine batteries. If you don't have a battery charger, use jumper cables to tie the two battery banks together. Doing this will let the inverter/charger charge the batteries up. While charging, while charging, periodically check that non of the batteries are not overheating, (just in case you have a bad battery).
If your engine batteries are able to be fully charged up. Measure the voltage again, after an hour or two of stopping the charge. Also attempt to start the engine and observe how well the starter turns over the engine after the full charge, and measure the battery voltage while the engine is running. The voltage should be higher than the voltage meausred when the batteries have rested an hour or two after charging.

By the sounds of it, it is likely that you have a charging issue. Often on these older coaches the battery isolator fails, this will prevent the batteries from getting charged and also can wipe out the alternator.

BTW, have you recently had your engine batteries disconnected???
If yes, it is possible that you accidentally connected your charge wire, that goes from the isolator to the engine battery positive, to the negative. Many of those wires are not color coded red and black, so it is easy to make that mistake. On most of these Safari coaches, the OEM wires running from the isolator are black, even though they should be red, or at least labeled. I've seen this mistake happen on numerous occasions. So if you are not getting a charge, and you recently had your battery cables disconnected, I would suggest that you double check and trace the wire that runs from the isolator to the engine battery bank and make sure it is connected to the positive terminal, even thought this wire will likely be black in color.
Please let us know what you find...
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
geantbrun
Posts: 48
Joined: Fri Nov 01, 2019 12:52 pm

Re: Engine does not start, transmission selector problem

Post by geantbrun »

Hi again
It seems that you ate right again. I am at an automotive store to check the batteries and they tell me that they are dead. My batteries are 1000A but they only have 800A (150$) or 1080A (400$). I don't know if 800 is sufficient or not. Your advice would be very welcome!
Regards
Patrick
Safari Sahara 96
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Engine does not start, transmission selector problem

Post by stuplich@ymail.com »

geantbrun wrote: Tue Jul 28, 2020 8:58 am Hi again
It seems that you ate right again. I am at an automotive store to check the batteries and they tell me that they are dead. My batteries are 1000A but they only have 800A (150$) or 1080A (400$). I don't know if 800 is sufficient or not. Your advice would be very welcome!
Regards
Patrick
Safari Sahara 96
Patrick
I'm using 2 of these 950 cold cranking amp Duracell batteries as my chassis batteries: https://www.batteriesplus.com/product-d ... ra/sli31sa
Last edited by stuplich@ymail.com on Tue Jul 28, 2020 10:13 am, edited 1 time in total.
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
geantbrun
Posts: 48
Joined: Fri Nov 01, 2019 12:52 pm

Re: Engine does not start, transmission selector problem

Post by geantbrun »

Thank you Mr Mel, I will go for the same. They found 950 in the group 31, commercial. They are not deep cycle though, does it matter?
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: Engine does not start, transmission selector problem

Post by stuplich@ymail.com »

geantbrun wrote: Tue Jul 28, 2020 10:12 am Thank you Mr Mel, I will go for the same. They found 950 in the group 31, commercial.
They are not deep cycle though, does it matter?
Patrick
Deep cycle not needed for chassis batteries.
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
geantbrun
Posts: 48
Joined: Fri Nov 01, 2019 12:52 pm

Re: Engine does not start, transmission selector problem

Post by geantbrun »

thank you to all of you, Brett, Mel, John and Bob!
very appreciated as usual
Patrick
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