Hi, I want to convert loop spiral to pencils as today I want to move my 300D and had a hard start (three cycles to start).

I want to keep the time of the original relay and will use a second relay to put more amps through the plugs.

Is this diagram safe to use ?

Not possible to convert to pencil plugs and pencil relay? I think even the glow plug relay is a separate section from the main harness.

Sixto
98 E320s sedan and wagon
02 C320 wagon

The point of the original Mercedes system is partly to protect the plugs - there's a chance you'll burn them out if you start using them for long than intended.

If you are having a rough time getting the engine started have a look at the condition of the engine oil (fresh oil always helps), the health of the starter (a rebuilt starter spins faster) and if necessary consider fitting a block heater.

I feel compelled to add that In most (weather) situations in the Netherlands I've never had trouble starting my OM617 (or any other vehicle)

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

All done except glow spirals and injectors.

My '78 uses the stock setup with no problems except the glow timer doesn't shut off until you engage the starter so I wouldn't worry about an extra relay myself.

PS They're a loop not a spiral and these same questions seem to come up every couple weeks so a search would help you out

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1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

I doubt the pencil relays aren’t going to draw 120a, and your relay coil isn’t going to draw 80a. You need to install an appropriate fuse on the 30/87 run for this to even be safe. It doesn’t seem that your added relay has any purpose.

? When was the last time you adjusted the valves ? .

This is the # 1 cause of hard Winter starting .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Been measured (only one adjusted)

these pencils draw 15A each instead of 10A so relay cant handle it I guess.

If this is for a w115 300D the only issue I see is with the thermo time switch not being in the loop somewhere to tell you when the plugs are hot enough. It acts as the ground for the loop glow plugs in the original system.



Perhaps it could be connected to terminal 85 in your diagram? There are two connections on the switch, one for the original plugs and the other is for the gp light in the dash. I would connect the one for the plugs to 85

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Marc-André

W115 1975 300D "Geraldine"
W115 1976 300D parts/tutorial car

the original thermoswitch on the block will be used (attached to the old relay)

So you need a 100a fusable link in place of the 150. And your 85/86 coil draws maybe 1a, so a small fuse there. Where did you find a 120a relay?

The standard for years has been to use the old ford starter relay that bolts to the side fender apron. Both cheap and reasonably reliable. Still available easily as well but this may pass with time.

Did I forget to mention cheap and normally deals with the full current in a ford starter? Actually I have never heard of a reasonable alternative to them.

Ford starter solenoid would have been my choice. But he’s showing something with DIN terminal designations, thus the question.

Jeeze ;

Don't screw around with barnyard starter relay bodge repairs ~ fix the darn thing properly, there's myriad posts on how to do this using cheap junkyard parts .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I want to keep the original relay to use it as a timer.