say you have 5 glow plugs (n/a 300d) and 4 wires (n/a 240d). would you:

a) run a wire from gp4 top to gp5 top?
b) run a wire from gp1 top to gp2 top?
c) splice the extra gp to the adjacent gp?

it's a 1980 240d body with 300d motor.

my answer was c. let me know SOON if i'm wrong.

I'd buy a five cylinder glow plug relay and install it. You can prolly find a good used one for not too much here.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If all I had was a 4 wire, I would send each wire to one GP and one would be lonely.

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif

A b or c, it doesn't matter, it just needs 12 volts.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

just do not use #1 for the sharing plug, as it'll draw too many amps for the controller brain circuit...
personally, I'd pull a harness and 5cyl relay from one of my stash, or a junk yard...
I think if you follow either path above, the light will be wonky... but the relay should handle it.2-4 are all linked together inside the relay IIRC...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

choice c it is! until i can make it to the junk yard. thanks!

What's the difference between a 616 and 617 relay? I'm thinking it's just the harness. No?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

nope.
5th pin is not present on the 240 relay...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Upper Pic is the Glow Plug Connector and the individual Pin Coupling for the Wires. It could be you can add Wire to your existing connector.

Or change the whole Conntector with new Pin Couplings.

Don't remember where the pic came from.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

The new relays are used for either 4 or 5 cylinder engines, the plug going to the glow plugs themselves will not have a fifth connector.

Attached Thumbnails

 

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83 SD

84 CD

my understanding is that you would have to replace both the relay and the wiring to the gp's. i'm just wanting to get it on the road right now. these things are getting hard to find in the junkyard. my goal is to get the rear diff changed to match my motor. i'm sure i'll be asking questions about that.

You only need to run an extra wire to the extra GP when you change to a 5 GP relay.

If you do not want to spend the money on an used 5GP relay or it is a temp arrangement then this is what I would do.

1) tap a small wire from any GP and connect it to a normal 20A relay. Use the relay contacts to drive the 5th GP. Source the current from battery. You can add a fuse if necessary.

2) If you do it this way then the GP light on dash will work as normal. Otherwise it may be funky as the load is not balance on the 4 wires.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Clever, but a five cyl relay would be simpler with no cobbling.

(really ingenious!)

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Relays at my local jy are $2 ea. Not sure what they charge for a wiring loom but it cant be much.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

If GP relay is only $2 then it is not worth any effort to mess around to make do.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.