Safari CAT Won't Start

[CarlGeo]

97 Safari CAT 3126 Allison MD 3060. Earlier today started just fine, but about 3 hours later will not start. Turn the switch on and all dash lights are on including Silverleaf monitor and 'wait to start'. Battery voltage is about 12.5 both chassis batteries. Transmission windows both show N N.
Where do I start looking? Solenoid relay, ignition switch? All suggestions appreciated.

[CarlGeo]

Hello to All,

I have found and fixed the problem. Today, I started retracing my earlier investigation along with everyones suggestions. Started with the batteries and their connections. I found the 12 ga. wire on the chassis positive terminal to the ECM was broken inside the barrel of the terminal, and therefore no connection. Replaced the connection and it started just like it should.
I truly appreciate everyones suggestions and comments. I check into and tried everyone. Thank You!
Carl

[Ivylog]

It's not your ignition switch as the one at the back bypasses it. Take a hammer and hit the starter several times and then try although it sounds like a starter solenoid problem. I would take a screwdriver and short between the small wire and the large + lug on the solenoid bypassing everything other than the batteries and their cables.
*Having thought about this a little more, did you have the ignition switch on when you tried to start from the back? The ignition switch has to be on/working to give power to the injection pump. If shorting the starter solenoid makes the starter work, then it's back to the ignition switch.

[FIRE_UP]

lj2654 wrote:
How are your battery connections...check for terminal corrosion and tightness of lugs....check the grounds to be sure they are tight.

That was going to be my suggestion. Those battery grounds, exist in bad joo-joo environment. When we purchased our coach and got it home, we didn't have any ignition or, starting problems but, in doing a thorough inspection of the entire battery system, I crawled under the big beast and found the ground cable attachment points on the frame. Wow, those were seriously rusted/corroded. I was amazed that the big CAT even cranked over with those looking like they did.

So, a bit of up-side-down work for a while and I had clean, nice connections. So, it maybe worth a look-see at those ground connections. They're under the phrase, "Out of sight/Out of mind" thing.
Scott

[CarlGeo]

Ivylog wrote:
Do you have a switch in the back that lets you start it from back there? My previous Beaver had it and so does this MH. I'd start at the ignition switch.

Yes, I do have the engine start switch at the rear compartment, and I just tried it and it did not work. It was dead just like the ignition switch. The ignition switch may be the culprit.
Thank you for bringing that to my attention.

[CarlGeo]

lj2654 wrote:
How are your battery connections...check for terminal corrosion and tightness of lugs....check the grounds to be sure they are tight.

The battery connections are tight and clean, no corrosion. I have not yet checked all the grounds, but will do that tomorrow.

Thank you
Carl

[CarlGeo]

JohnnyT wrote:
Does the motor turn over? Are there any sounds or indications that the starting sequence has been initiated? If you could provide any additional information... There are a lot of folks that can provide some insights... It would also help to narrow down what the battery voltage is and how you determined it...

If I had the issue I will be wanting to see if I had the proper voltage to the solenoid.. and if I had the proper voltage to the starter... There are a couple of steps to get there.

I have always been of the school eliminate the simple things first. Usually the simple thing is low battery voltage... Then solenoid, starter motor, ignition switch...

You will need a multimeter and a way (usually a wire) to bypass the ignition switch and energize the starter solenoid....

JohnnyT

Johnny
Yes, when the switch is turned on everything lights up normally, the dash lights come on, the 'wait to start' light illuminates, and the Silverleaf monitor starts, and the air compressor for the chassis starts running, BUT the engine does not turn over when the switch is turned to the start position.
I checked the battery voltage directly at the batteries with a digital volt meter.
I have not checked voltage at the starter solenoid, nor have I checked the ignition switch.
Thanks for the suggestions
Carl

[Electronpusher]

Been a while since I sold my '96 but..

Even though it shows NN I would look at the Allison book for failure modes and reset procedure. ..

Also I seem to remember the brake light switch being part of the interlock and it is prone to failure. .. It can be wired around for engine start....

Good luck..

[Ivylog]

Do you have a switch in the back that lets you start it from back there? My previous Beaver had it and so does this MH. I'd start at the ignition switch.

[lj2654]

How are your battery connections...check for terminal corrosion and tightness of lugs....check the grounds to be sure they are tight.

[JohnnyT]

Does the motor turn over? Are there any sounds or indications that the starting sequence has been initiated? If you could provide any additional information... There are a lot of folks that can provide some insights... It would also help to narrow down what the battery voltage is and how you determined it...

If I had the issue I will be wanting to see if I had the proper voltage to the solenoid.. and if I had the proper voltage to the starter... There are a couple of steps to get there.

I have always been of the school eliminate the simple things first. Usually the simple thing is low battery voltage... Then solenoid, starter motor, ignition switch...

You will need a multimeter and a way (usually a wire) to bypass the ignition switch and energize the starter solenoid....

JohnnyT