Community Forums

Skip426 · 08-27-2014, 09:26 PM

My 99 Freightliner chassis has these 2 fuse and relay boxes as part of the chassis harness, Winne may have located these boxes in a different location , but mine are above the gen set, and one contains an ignition relay that if yours has the same, the relay may be stuck constantly feeding power to the ECM.

RandyS549 · 08-31-2014, 01:03 PM

I had the same problem with a '93 Rockwood Embassy diesel pusher on a Spartan ec2000 chassis. Actually, I created the problem when I found a wire with melted insulation in the front electrical box. I assumed (there's that word again) the melted wire was a fuseable link, and I replaced it with one. The problem continued. To shut the engine down I had to raise the bed and unplug the fuel pump manually.

Spartan Technical Support was kind enough to send me a wiring diagram for the chassis. It was then I discovered I has replaced a blown diode with a fuseable link. The link was allowing voltage to flow backward through the circuit and kept the fuel pump running.

A diode will only allow electricity to flow in one direction. As soon as I replaced the fuseable link with a diode the engine shutdown normally. The diode must be put in in the right direction of current flow or the problem will continue.

I hope this helps.

Randy

GlennLever · 08-31-2014, 03:34 PM

I had the exact same problem.

Cummins has a revised fuel shut of solenoid.

It has a stronger shut off spring.

The way it works is when you crank the engine you energize a strong electromagnet which pulls the valve open and puts tension on the shut of spring.

Once the engine starts the first electromagnet is shut off an a weaker one is energized to keep the valve open.

When you shut the key off that magnet is denergized and the spring pulls the valve closed. This is a DIY project, the shut off solenoid is right on top of the engine easy to get to .

The part is not cheap though (get the Cummins name brand part).

lsucajun · 09-05-2014, 11:30 AM

Well, finally found it. early in the story, I found a thread that indicated that there is a diode in the alternator circuit if shorted will allow 12 vdc back to the ignition circuit and keep power to the ECM. I called the shop that was working on the RV and sent them a fax to look for this. They informed me that my unit did not have the diode and that wasn't the problem. I got the wiring diagrams from freightliner and low and behold, there was the diode. ran a simple test and proved that was the problem. changed the $2.00 diode. Problem solved...

Skip426 · 09-05-2014, 11:39 AM

Thanks for posting that you're fixed up, and giving the exact nature of the repair required.
My schematics show that diode too, and I'll keep it in mind , if I start having similar issues.
Any hope of a refund on the ECM, or was your serial number programed in ?

noserider · 09-05-2014, 01:44 PM

Quote:

Originally Posted by lsucajun

Well, finally found it. early in the story, I found a thread that indicated that there is a diode in the alternator circuit if shorted will allow 12 vdc back to the ignition circuit and keep power to the ECM. I called the shop that was working on the RV and sent them a fax to look for this. They informed me that my unit did not have the diode and that wasn't the problem. I got the wiring diagrams from freightliner and low and behold, there was the diode. ran a simple test and proved that was the problem. changed the $2.00 diode. Problem solved...

Well done.

Bummer48 · 09-05-2014, 02:49 PM

I recently had same problem 2 weeks ago and drove from Columbus, Ohio to Cummins Dealer in Omaha, Ne.as it was on a Saturday and we were going to make a stop there anyway and would have to wait until they opened on Monday. After arriving Cummins I then turned off engine by turning the battery disconnect toggle switch located in bay where batteries located. Problem resolved by replacing ignition switch solenoid located in forward bay under drivers seat. I had just replaced it the day before we left Columbus and auto parts place sold me the wrong one. If that is your problem, make sure it is severe duty, constant duty and heavy amperage. Cummins should be able to help you. Cost was approx. $45. Hope this helps