Cummins Won't Start

[smokeater75]

Hi everyone,

I'm wondering if anyone out there has had this problem. We are currently in Salt Lake City Utah, I went to start the motorhome yesterday and it wouldn't start. I had the same problem 2yrs ago in Sioux City Iowa, the RV was towed to a cummins dealer and after they backed it into the shop the service tech started it and asked me what the problem was. They checked everything and I mean everything and could find nothing wrong. Here we are two yrs later and bingo the identical problem, you turn the key wait to start light goes out try to start the engine and the volt meter dips to 8 volts and nothing happens. I did and checked everything I could just like last time with the same results. I have brand new batteries, starter and deep cycle, its a pain in you know where.

Coach-net is sending a tow truck first thing Monday morning to take the motorhome to a Cummins dealer, anyone had this problem.

Thanks Smokeater 75

2003 Monaco Windsor,Cummins 8.8 L .

[wolfe10]

That kind of voltage drop would indicate:

Weak battery OR bad cable connection OR bad starter.

Start by having the batteries load tested, remove, clean and properly tighten all large connections between battery and starter. If the problem continues, suspect the starter.

Brett

[smokeater75]

Thanks Brett, I'm thinking its the starter. Batteries are good, it almost seems like theirs a dead spot on the starter and if it lands there bingo.

Thanks again for suggestions.

I will post the results after Monday when it gets towed to the shop.

[dickandlois]

Smokeater, If you have a soft blow hammer laying around give the starter a couple of hits and see if it turns over. A piece of wood works also. Metal hammer not quite as hard of a hit !!! Have the DW or someone try to start it while giving it a hit or two --- just do not jump to far if it starts, can be a little startling !! pun intended !!!

If it starts it is the starter !!!!!

Rich

[smokeater75]

Thanks Rich, tried that too, the good news is it didn't happen on the road, we are comfortably in a RV park hooked up, so we were very lucky in that respect.

Thanks again for the info.

[desertdeals69]

If the voltage drops to 8 volts when trying to crank chances are its not the starter. It might be the starter solenoid or the connections at the solenoid. When cranking what is the voltage at the battery terminal? Be sure to check the ground circuit also.

[bobbyks]

My Cummins 425 is in the shop now to replace the starter, I was lucky to be at home and had a local tech come to get started, he had to bang and beat on the starter to get it engaged and get to his shop.

[smokeater75]

Hi everyone and thanks for the info. Sorry about the voltage error, the voltage drops to just below 12 volts on the dash volt-meter when I try to start it. Thanks again. Smokeater75

[ticat900]

If the voltage drops to 8 volts when trying to crank chances are its not the starter. It might be the starter solenoid or the connections at the solenoid. When cranking what is the voltage at the battery terminal? Be sure to check the ground circuit also.

how do u check the voltage when cranking when it will not crank?

[smokeater75]

I didn't say it was cranking, that's the problem there's nothing. All that happens when you turn the key after the wait to start light goes out is the volt meter drops to just below 12 volts and nothing.

[dickandlois]

Smokeater,

With very little voltage drop, that could mean that the relay in the starter circuit is not working.

Wat Chassis do you have ? If its a Freightliner Chassis, then look for a large wire running from the starter solenoid to a relay that frequently is located / mounted to the frame rail close to the starter.

Check to see if the small wire(s) from the ignition switch are OK, nice clean connection(s) and the wire is not broken if it is protected with shrink tubing. Check to see if you have voltage at the relay when the key to turned to start. If No voltage then its a problem other then the starter.

With the key on very carefully jump across the large terminals on the relay if the starter engages, you have a bad relay .....

Just be very careful when jumping these terminals !!! Very High Current Area . If you are not sure just get some help !!!!!

Just be aware that being under a coach engine when its cranking and starts can be a little hair raising !!

Should it crank you have found the problem and can get it started so no tow is needed to get where you need to get it replaced...

EDIT 4-8-2013----A little slow yesterday. If you have a Monaco the starter relay in often in the rear engine compartment electrical box.

Work Safe Rich..

[smokeater75]

Good morning everyone, its 10:20 am here in Salt lake city. The tow truck driver came yesterday morning and between the two of us and a lot of banging on the starter we got the motorhome started much to both of our relief. I drove over to Rocky Mountain Cummins and they took the RV in and spent two hrs doing a diagnostic and just like two years ago in Sioux city Iowa at a Cummins dealer they could find nothing wrong.

The measured voltage drop on the starter cables were as follows 0.77 VDC on the positive cable and 0.94 on the negative cable. The starter cables and batteries are OK. The starter was cranked several times without any problems. The thing that bothers me the most is not the $400.00 dollars it cost but two yrs ago the same thing happened with the same result. It took 22,000 miles and 2yrs with who knows how many starts and stops for it to resurface again. The Cummins people say that they only look at what goes on in the engine bay. They have no idea what the manufacturer's have done between there and the ignition switch on the dash. So here we go again wondering when it will happen again.

All part of the adventure I guess, thanks again to everyone who responded.

Smokeater75

[dickandlois]

Smokeater, If you live out our way I would get you into the local starter shop and have JR rebuild it.

The fact that you got it to work by hitting it leads to knowing its an issue with the starter.

Could you get the OEM part number for the starter and post it for me ?

Will do a little book work and see what I can find out about it and see what options and prices I can find.

Good to have a few options, regarding replacements and where to get one. I have been down that road and now keep a spare in the coach. Mine died and the dealer we stopped at did not stock it, so I asked if they would install the one I carry. They had no problem with it.

Rich.

[ticat900]

Good morning everyone, its 10:20 am here in Salt lake city. The tow truck driver came yesterday morning and between the two of us and a lot of banging on the starter we got the motorhome started much to both of our relief. I drove over to Rocky Mountain Cummins and they took the RV in and spent two hrs doing a diagnostic and just like two years ago in Sioux city Iowa at a Cummins dealer they could find nothing wrong.

The measured voltage drop on the starter cables were as follows 0.77 VDC on the positive cable and 0.94 on the negative cable. The starter cables and batteries are OK. The starter was cranked several times without any problems. The thing that bothers me the most is not the $400.00 dollars it cost but two yrs ago the same thing happened with the same result. It took 22,000 miles and 2yrs with who knows how many starts and stops for it to resurface again. The Cummins people say that they only look at what goes on in the engine bay. They have no idea what the manufacturer's have done between there and the ignition switch on the dash. So here we go again wondering when it will happen again.

All part of the adventure I guess, thanks again to everyone who responded.

Smokeater75

starter on ebay is 198.00 I would have just changed it rather than waste money chasing the dogs tail.The fact that you banged on the starter and it turned over would be enough to convince me to replace it as your cost to diagnoise was more than that and still no results

[HarveyWhite]

i'm with Rich if you tapped on the starter and it started then you need a starter, or at least it rebuilt. it will catch you somewhere and you will be in a bind that's for sure. Cummins are known for the solenoid going bad they sell kits for just the solenoid.

[smokeater75]

Thanks to everyone who replied, I guess I should have mentioned this back in April. Cummins Rocky Mountain in Salt Lake City put in a new starter, and here we are 5000 miles later and everything seems to be fine. Thanks again. Smokeater75.