Loop to pencil glow plug conversion help needed - PeachParts Mercedes-Benz Forum

mplafleur · #1 12-15-2008, 10:48 PM

My old 240D I've been rebuilding has the Bosch pencil glow plug conversion.

We will be trying to start the engine after the rebuild tomorrow if I can get the glow plugs to glow. It had the Bosch pencil glow plug conversion kit installed (not by me) since I last owned the car.

http://catalog.worldpac.com/buymb/022406/image.jsp?title=Glow%20Plug&url=http%3A//img.eautopartscatalog.com/live/F110188322BOS.JPG

Does anyone have the instruction sheet for this kit? I need to know the pinout and description for the harness/relay so I can troubleshoot this. The relay box is getting power, but it's not turning the relay on. There is also an external relay wired into the harness and a connection to the coolant switch on the head.

Diesel911 · #2 12-16-2008, 01:17 AM

This site has a pictoral on how to instal it takes a while to open and you need to scroll down the page.

http://www.dieselgiant.com/mercedesdieselloopglowplugrepair.htm

vox_incognita · #3 12-16-2008, 07:25 AM

http://www.hehlhans.de/engtipp14.htm

mplafleur · #4 12-16-2008, 09:00 AM

Quote:

Originally Posted by Diesel911

This site has a pictoral on how to instal it takes a while to open and you need to scroll down the page.

http://www.dieselgiant.com/mercedesdieselloopglowplugrepair.htm

Sorry. Your site doesn't show the Bosch relay or give the pinout for the provided cable.

mplafleur · #5 12-16-2008, 09:09 AM

It's this relay unit and cable I need information for...

kerry · #6 12-16-2008, 09:29 AM

If you need to try starting it before you figure out the relay, you could just use a jumper wire from the battery to one of the plugs. I think the rest of the plugs should be energized from the short wires that connect them together. (if it's set up the way I've seen others set up)

vox_incognita · #7 12-16-2008, 10:07 AM

http://home.comcast.net/~phantoms/vacuum/index.htm
and
http://www.hehlhans.de/tipp14.htm
http://www.hehlhans.de/engtipp14.htm
The first link describes how to solder the new wiring to the existing one-which of the new 4 colored wires connects to which of the old ones(bottom of page)...
Good luck!

mplafleur · #8 12-16-2008, 09:45 PM

I had two bad glow plugs. Both of them open.

I also still had the original ground braid on the number one plug.

After I removed the braid, the glow plug controller worked.

The car won't start yet (on two plugs only), but it is starting to fire.

We'll keep the block heater on all night and tomorrow and try again.

kerry · #9 12-16-2008, 09:55 PM

Quote:

Originally Posted by mplafleur

I
I also still had the original ground braid on the number one plug.

Did it ever run in that configuration?

vstech · #10 12-16-2008, 10:29 PM

Quote:

Originally Posted by kerry

Did it ever run in that configuration?

the loop style plugs needed the braid... it direct shorts the pencils this way. i HOPE the relay still works if he's had power to it like this...

kerry · #11 12-16-2008, 10:47 PM

Quote:

Originally Posted by vstech

.. it direct shorts the pencils this way. ..

That's why I asked if they functioned in this configuration. I don't see how it is possible that they worked that way.

vstech · #12 12-17-2008, 10:36 AM

Quote:

Originally Posted by mplafleur

It's this relay unit and cable I need information for...

why did you put in the relay? what year is your 240? did the old relay fail? or did you have a gorilla knob? if you had a relay before, you can just use it... just put in the pencils and wire it to the existing relay, and change the fuse strip to an 80amp. and yes, remove the ground strap from the #1 plug.

kerry · #13 12-17-2008, 10:59 AM

Quote:

Originally Posted by vstech

why did you put in the relay? what year is your 240? did the old relay fail? or did you have a gorilla knob? if you had a relay before, you can just use it... just put in the pencils and wire it to the existing relay, and change the fuse strip to an 80amp. and yes, remove the ground strap from the #1 plug.

Some of the pencil retrofit kits come with a substitute relay.

mplafleur · #14 12-17-2008, 11:28 AM

Quote:

Originally Posted by vstech

why did you put in the relay? what year is your 240? did the old relay fail? or did you have a gorilla knob? if you had a relay before, you can just use it... just put in the pencils and wire it to the existing relay, and change the fuse strip to an 80amp. and yes, remove the ground strap from the #1 plug.

I didn't do the conversion. It was done between the two times we owned the car.

The car doesn't have the gorilla knob. It is a 1980.