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maxwell18 · 09-04-2013, 12:33 PM

I have a 2000 H/R Ambassador 5.9 been running ok, tried to start today turn over but would no start, funny thing starter continued to crank even when I turned key off start position and would stop when I pulled the key out of key slot? Starter Switch?

chasfm11 · 09-04-2013, 06:56 PM

I suspect that we have the same engine and the same setup (see my signature).

Assuming that it is a Freightliner chassis, there is a relay on the driver's side frame rail, inside and just about beside the engine. Mine was bad but it gave me a different symptom from yours. If everything was working correctly, you could short the main poles on that relay and the starter will turn over. There are two smaller leads and one of them comes from ignition switch start circuit. I'm guessing that what happened in your case is that that relay stuck closed. That would definitely keep the starter turning even with the ignition off.

As to why the engine won't start, that may be a different issue. If the starter is engaging and cranking normally. I would start looking at fuel delivery. But I would work on the relay first and then see if you still have a staring problem.

I'm not sure why Freightliner put relays in such an exposed position. The relays that control the air heat grid for starting are on the passenger side frame rail and I've had to replace one of those, too. They just corrode because of the dirt and moisture off the road.

Mr_D · 09-04-2013, 07:04 PM

With a diesel engine there are two things required to run: air and fuel. Assuming the inlet tract is not completely plugged then it's a fuel problem. Start with the fuel shut off solenoid.