i recently bought a 79 300d it was hard to start when i bought it thats why i got it so cheap anyhow i bought 5 new bosch glow plugs hooked them up and nothing so i ran a wire from the battery i am worried i burnt them up they are the large thread loop style plugs on the bottom they say 0.9v also there was a ground wire hooked to the front glowplug is the ground wire supposed to be hooked up if its hooked up the the gp indicator light comes on for 20 30 secs if its not hooked up then it does nothing whenever i do hook up the ground wire the power supply wire gets hot redhot on the front glowplug is this normal? also i have never heard it click i really could use some help thanks

I know that the individual Glow Plug loops/filiments will burn in two if you test them on the Battery. I don't understand how the system works but have a tiny idea that the Resistance Wires keep too much amperage or voltage from going through the Glow Plugs.

You will need to look in the DIY Links on how to trouble shoot your particular Glow Plug System.
People have said the zig-zag Resistance wires willl glow in the Dark but none of the other wires should be getting red hot.

DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

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84 300D, 82 Volvo 244Gl Diesel

Sorry that's past the shame part, it would be a shame if the owner installed 27" rims and a glittered paint job....this is just unmentionable....but hey at least the cylinders have been honed....

If you plan to be a regular poster, I would start a new thread about the car. Chances are the hard starting is a few things. I would personally get rid of the loop plugs and buy the pencil fast glows. You can then eliminate the ground wire. Here is a pre made kit, if your not able to manufacture the wires. If you can make the wires, you can get a set of 5 plugs cheaper then this.

http://www.ebay.com/itm/NEW-MERCEDES-QUICK-FAST-GLOW-PLUG-KIT-300D-300-D-CD-TD-/200567616047?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3A300D&hash=item2eb2c2f22f&vxp=mtr

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so do i wire these to the original power wire or can i hook them up directly to the battery with a switch in between to turn them off and on? i really dont want to burn up another set its getting expensive quick also im new to this how do i start a new thread? much thanks

well i just bought the ones you recomended should get them fri or sat now i just need to know which way to hook them up thanks

i dont understand. are you for some reason trying to bypass the original wiring in the car?

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1981 NA 300D 310k miles

I moved this as a separate thread for you.

Glow plugs link thread All diesel models
Glow plugs link thread - PeachParts Mercedes ShopForum

I suggest you focus special attention on this information.

Early loop style glow plug system, great training material.
ME07

glow plug conversion kit thread links (Loop to Pencil)
glow plug conversion kit thread links - PeachParts Mercedes ShopForum

Glow plug enhancement « The sad mechanic exercise


Have a great day.

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1985 300SD
1983 300D
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Make sure you ream out the glow plug holes. This is a critical step to eliminate carbon build up as a contributor to your problem.

not needed on loop style plugs... the hole is HUGE compared to the pencil version.
follow this pictorial to get the pencils installed.
Mercedes Diesel Glow Plug Repair

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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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

On loop plugs the ground wire should be attached the the heavy wires between the plugs should glow red when operating. That is normal.
To install the new retrofit pencil plugs (you did purchase the retrofit style plugs and not the standard pencil plugs -right?), remove the existing glow plugs and wiring, install the new plugs. Connect the one nearest the firewall to the original hot wire coming from the small fuse box on the firewall and then connect jumper wires from that plug to each of the other plugs in turn. Do not reconnect the ground wire. Your system should then be operational.
However, the fact that your current glow plug indicator light is not working shows that there's a problem in the existing system. It could simply be a failed glowplug but it could also be something else.
When you first got the car, did you check the heavy 80 amp fuse in that small fusebox on the firewall to make sure it was intact?

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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

Maybe not, but they do sell the Glow Plug reamer for the large type plugs.

Pelican Parts.com - Glow Plug Bore Reamer, Large Type


depending on Chassis number, some use a 50 amp and then after a certain chassis # it was increased to 80 amp. are the loop 50 and the up graded pencil one`s 80 amp?


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

correct.

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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 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

The Loop/Filiment type Glow Plugs can suffer from the Carbon issue and Carbon forming a bridge that essentially acts as a ground creating a short circuit.
Since they are not supposed to be grounded throug the Glow Plug Body it burns the Loop/Filiment.

When you install the Adapter Glow Plugs there is a lot of empty space; maybe even 1/8-3/16" around the heater element end of the Glow Plug so it would take a lot of carbon build up to effect them.

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84 300D, 82 Volvo 244Gl Diesel

The Adapter Glow Plugs can be connected directly to the Battery. Most people install a Ford type Starter Solenoid and that keeps you from having to find a Push Button Switch that will handle 80 amps.

When the Glow Plug Relay on My Volvo went bad I used the Ford type Starter Solenoid ($5 from the Junk Yard) and a Switch.
I have no Fuse in My system. I did that back in 1993-94 and have had no issues with it.

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84 300D, 82 Volvo 244Gl Diesel

There's no need for that on a 79. The original relay will operate the pencil plugs just like it did the loop plugs.

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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