Series 111 Diesel won't start.

"Molesworth" wrote..........

First of all, does the yellow cold start warning lamp work? It might be a bit crude but it can give a good indication of what's wrong. If it lights brightly then there's usually a glow plug gone short circuit to ground (possibly from being overtightened). If it lights dimly and after a few seconds glows brighter then that is what it should do with everything ok. If it doesn't light at all then there is usually a glow plug open circuit (burned out) assuming there's power from the switch and through the resistor. To check use a piece of wire connected one end from the battery live and stripping the other end down with just a couple of strands exposed to act as a fuse flash this on the input to the resistor working your way forward to the front glow plug until you get a spark, this will make it obvious which glow plug is open circuit as they are wired in series. If it sparks at the resistor first off then you may have a power supply fault before the resistor, or a shorting glow plug or connection to them. In this case you will have to check the supply or disconnect each glow plug in turn and check them to earth with an ohmmeter.

The reason the light increases in brightness as the heater switch position is held for a few seconds is the supply resistor gets hot, it's resistance increases, cuts down the supply to the heater plugs and more current tries to pass through the little bulb which is wired across the resistor. The heaters shouldn't require to be held on for more than 6 to 8 seconds in any case unless the engine is getting tired, i.e. valve seats, bores or fuel problems.

HTH, Martin

No light on when switched on.

Temps here in New Orleans are about 40-50F.

Can the plugs be hot-wired?

OK - Got it started.

This LR was petrol and was changed to a diesel, so the wiring ain't right.

The hot wire to the resistor comes direct from the off side of the solenoid! The glow lamp isn't wired at all.

I switched the resistor wire to the hot side of the solenoid for ten seconds, and Lo, it started immediately. Then, with it running, switched the wire back again!

"Molesworth" wrote:..........

Heh, no wonder it's not lighting up. Wire the warning lamp in parallel with the resistor, (each end of the bulb to each end of the resistor), then pick up a live from the starter or battery and wire up to the input of the heater resistor through either a separate button switch or change the actual switch assembly on the back of the ignition lock to the diesel type which has the extra terminal for the glow plugs or change the complete lock assembly (whichever you find easier). I think the warning lamp bulb on the diesel is only about 6volts rather than the 12volt one fitted for the petrol system, the petrol one is just connected to earth but the diesel bulb works on a different principle. Also when the heater button or switch is activated you will see a slight dimming of the oil pressure warning light and ignition warning lamp under normal conditions as a rough check. By the way, when wiring in the warning lamp to the resistor, don't forget to disconnect and remove the ignition live feed to the bulb.

The engine may be a bit tired as mine will start without heat at those sort of temperatures and I never use the glow plugs for more than 7 seconds even when it's below freezing and it's about 27 years since mine was rebuilt.

It seems like it just needs wiring correctly and there's nothing wrong with the glow plugs (heaters) then.

On or around Tue, 29 Dec 2009 20:28:13 -0000, "Oily" enlightened us thusly:

Did they change them then? The older series diesels had series-wired heater plugs which took a good 30s in cold weather to get hot enough. The 1800 sherpa had the same evil system, except on that, on a cold day, it took anything up to 90s of preheat.

"Austin Shackles" wrote............

You're going back a long way to the 1800 Sherpa, AFAIR those heater plugs were the same as the 1500, not an exposed element but encased in a metal tube and took ages to even begin to get warm, at least 40 seconds, but completely different to the Series type series connected ones. The old Landrover type, maximum ten seconds or you will burn them out, even with the protection of the resistor.

These engines start well without them, even in this cold weather I've never had cause to wait for them which says something for the design as mine has now done 300k+ miles with only service items attended to.

Paddocks used to do a parallel wired (12v each) conversion set for the Series 2 and 3 at a good price but I don't know if they still do. The only trouble with the parallel wired system is you don't notice if any are dud until it's too late. With the old series connected system it's either all or nothing as when one burns out the whole lot goes open circuit and none of them work. Having said that I prefer the old type as when they do let you down (which isn't at all often) you can easily trace the bad one and short circuit it temporarily to get you going.