Community Forums

Diesel Fool · 05-13-2012, 05:11 PM

Hi-

Pulling what's left of my hair out.

2004 Newmar Cat 300 will not start 38K miles

About a week ago I replaced both batteries on the diesel side. The house batteries were fine. The coach started with no problem. Next day replaced 9 of the 10 LED marker lights & all lit up perfectly. Next replaced 1 burned out tail lamp bulb & my wife started coach to check all signals: LH, RH, back up, 4 way. Made the mistake (?) of turning off ignition right after testing lamps instead of letting it run 5-10 minutes. Half an hour later started again, tested signals & again turned off the ignition too soon (?) - did not let it run 5-10 minutes which is or is not advised with diesel. I don’t know.

Next day would not crank. Dash lights up, wait to start & hear the usual sounds as is it waking up behind the dash. Also hear electronic activity back by the engine – like something is being energized. But no cranking whatsoever. Check engine light illuminates.

Checked all the flat blade style fuses, front & rear and all show green with tester. Checked new diesel & older house batteries with multi meter & shows OK voltage. Read about Silver Leaf electronics VMSpc code reader here & ordered one. Loaded it to a Vista laptop & plugged into the port above the diesel in the rear. (I don’t know if there is supposed to be another port under the dash.) But I get no diagnostics if I open that software before or after turning the ignition key to on.

I’m stumped. Did I screw up some relay or ??? by not letting it run 5-10 minutes. Never started & shut it down quickly before. I’m not opposed to getting a service call, but towing out of my driveway would probably be near impossible because of the incline with a sharp narrow turn at the end. I’m calling Silver Leaf tomorrow, their screen loads but clicking on diagnostics does not produce a list of anything. No codes appear.

Diesel Fool 34’ Freightliner chassis / Newmar Kountry Star coach bought new (never a problem before – except dash AC which was fixed 4 times under warranty & crapped out within a mile of leaving Branford, CT Freightliner.) I‘m reluctant to go back there for that on my dime.

EngineerMike · 05-13-2012, 05:29 PM

No crank but power to the dash is good, as its usually easy to locate the culprit. No worries about a few starts w/out warming up; your Cat is tougher than that.

Pretty sure its a connection in the starter circuit. Sounds like all other 12V stuff is working, but not enough juice from batteries (probably not batts themselves although possible there was a drain sufficient to pull batt's down below cranking level) to the starter (connections sometimes rattle loose over time).

I'd start w/the new batts & check all connections on cables, solenoids & relays to the starter. Bet you find one or more loose or corroded that need fixing.

BTW,

Mike Canter · 05-13-2012, 05:32 PM

When you turn the key to spin the starter you say you get nothing? No clicking or anything? Or is the motor spinning over but not firing? What does the volt meter show when you do this, does the needle drop? Turn the headlights on and have somebody watch them while you try and start it. Do they stay bright or go dim or go out. The Check Engine Light will be on because it didn't start. There is no set time limit to run a diesel before you shut it off. Silver Leaf probably will not show a code for the starter not spinning over. There should be no relay other than the starter solenoid between the key and the starter.

Check your Allison key pad and make sure it is on and the N is showing for in Neutral. The motor will not turn over if the Allison pad is not on.

Fred Cooper · 05-15-2012, 08:41 PM

Call the Freightliner help desk 1(800) 385-4357. Have your vin number available. They will pull up your exact wiring diagram and help you troubleshoot. I've always gotten great help from them...all for free.

fred

Air Baron · 05-16-2012, 06:59 AM

I just went thru this with my 2001 Newmar Cummins 350 with 21k miles. Working together with me at the ignition switch, the mechanic used a test light and then began wiggling wires while laying underneath the engine...found a corroded connection to the starter solenoid. I also had an 18 month old Interstate Workaholic 950 battery that had given up the ghost...but that did not prevent the cranking.

Rather than spending $250 (or more) on another service call to visit me at some remote campground, I am calling Spartan to get the wiring diagrams for my coach emailed to me in pdf. The mobile mechanic needed to see what relays are in the start circuit, and where they might be located. So do all of us who want to solve our own problems.

Mike Canter · 05-16-2012, 07:10 AM

Guys, you don't need a wiring diagram to troubleshoot a starter motor cranking system. It is the same as on a car. It is not that complicated and simple logic will prevail. Most owners manuals have a troubleshooting tree if the motor will not spin over.

Randy blase · 05-16-2012, 07:45 AM

Same thing happen to me this past weekend while camping got ready to leave and no start all the lights on dash came one and the buzzer when I turn key but no start it turn out to be corroded cables at starter toke them off clean them and put back on and she fired right up

Air Baron · 05-16-2012, 09:56 AM

Quote:

Originally Posted by Mike Canter

Guys, you don't need a wiring diagram to troubleshoot a starter motor cranking system. It is the same as on a car. It is not that complicated and simple logic will prevail. Most owners manuals have a troubleshooting tree if the motor will not spin over.

Really, is that so. Check out this thread. I don't know what I don't know, and these motorhomes evidently contain all sorts of surprises. You never know what you might find, or not find, or even where to find it.

http://www.irv2.com/forums/f25/isc-3...eas-70820.html

Mike
I was an AT2...who got out in '72.

Dennis

Mike Canter · 05-16-2012, 12:39 PM

AT2 Dennis they still had vacuum tubes when you got out.

. I was an AX then an AW then made it up to AWCS and then made Chief Warrant Officer. Retired as a CW04. I started out on vacuum tubes and transistors also. I was lucky and stayed in the P-3 community for 26 years.

The starter circuits are very simple. I have known cars to start without keys in the ignition also. There are just a few steps one has to do to isolate it down to the area of the problem.

The funniest thing I have seen was a tech remove the throttle controls out of a fighter cockpit and had both jets start up. Scared him to death. The jet was tied down and they stayed at idle. He didn't follow the procedures.

Mr_D · 05-16-2012, 12:53 PM

Our 2002 DSDP did the same thing last week. Turned out to be a bad starter on the Cummins. Cost us $1,008 for the part and labor, Coach Net paid the almost $700 towing bill.

Mike Canter · 05-16-2012, 12:59 PM

Wow that is a lot of money. You can buy a premium Denso geared starter for under $500 which is ten times better. That means he charged you five hours labor.

bbeane · 05-16-2012, 06:56 PM

Sounds to me like you might check your connections at the starter. Quick easy check is loosen wiggle retighten all connections try it. If it works bad connections remove and clean replace.
As others have said starter circuits are not complicated.

Diesel Fool · 05-20-2012, 10:24 PM

Thanks you for all the suggestions. Tried some. Will also call Freightliner - soon.

I have checked all the battery connections in the battery compartment. Found 3 Black ground cables on Cat near junction with Allison. One single cables had a bolt that came right out. The other two were Siamesed and that bolt broke off. There was so little room under this coach that I could not begin to think about extracting the threaded portion. Both of those grounds were too short to reach the other grounds mounting bolt so I fabricated a steel bracket to mount between those 2 cables to span the distance to the good ground mounting bolt. What a PIA. Cleaned all battery box compartment terminals & the previous 3 grounds to the Cat with electronic cleaner spray, sanded surfaces to get rid of remaining oxidation & assembled with dielectric grease. Tried to start: same as before – everything on dash lights up with usual sounds - but no cranking. After the wait to start light goes out, try with the battery booster switch – nothing but the check engine light illuminates.

The red positive cables mounting stud nuts to the starter are quite corroded. Also the access is terrible. Truthfully I think the mounting studs will break. If they do I’m screwed. Any ideas ??????

What really baffles me is this. After I replaced the two 12 volt coach batteries with new ones, my wife started the coach twice and then the next day it would not start. I’ve checked the voltage for both the 12 volt coach batteries & the two 6 volt house batteries & my digital multi meter shows good voltage. My BIL on the Midwest drives an 18 wheeler & advised that low water & oil level will prevent starting. Checked them also.

I read suggestions about relays & solenoids, but cannot figure how one would check them. I haven't "messed" with the ignition switch because I have no clue what to do.

Tomorrow I'm placing a paid WANTED display advt in the main Connecticut pulp newspaper that states: 2004 Cat 300 HP Diesel Trouble Shooter wanted. Generous reward for knowledgeable tech to troubleshoot my Cat diesel at my house. Not sure it will do any good. I'm not opposed to getting a tow but the left turn out of my driveway is not going to be an easy task for any pro. I doubt it can be done without excavation. Also read in Freightliner manual that air suspension must be inflated for a tow & drive shaft must be disconnected. Not sure how to inflate the suspension , but I can't see a drive shaft at all. My Dodge Dakota pickup has so much more ground clearance it makes me sick, cramped & claustrophobic under this coach. Sux in plain RV language.

Fred Cooper · 05-20-2012, 10:41 PM

Just a few thoughts. Might be worth what you've paid for them, but I hope they help.

Clearance under the coach can be improved by deploying the jacks, and then stabilizing with jack stands.

Have you considered rigging a 12 volt test lamp with long leads and connecting it to the 12 volt positive connection to the starter motor, with the other lead to a good ground. Run the leads out so that you can see the test lamp when you turn the key. If the lamp does not light when the key is turned, you have an electrical problem between the battery, ignition switch, relays, etc...anything affecting delivery to the starter motor.

If the light comes on, I'd remove the starter motor and have it tested.

If the drive shaft is removed for towing, be sure it is marked for alignment before it is removed. It needs to be replaced in the same position as it is removed.

Good luck with your problem.

Fred