This evening I was going to take the 240D to the grocery store however it wouldn't start. The glow plug light isn't coming on at all and from what i have read this is usually caused by the fuse on the firewall. I changed the fuse with a spare from my toolbox and that didn't help. I still have the trim off under the dash so I have access to the glow relay and I feel it clicking on when I turn the key to the preglow position. I don't have my meter here at the house so i can't confirm anything. If the first glow plug had failed would that cause the rest of them to fail?

If you have the Filament/Loop Style Glow Plugs (that are wired in series) of one Glow Plug goes bad the circuit is broken and none of them work. (The Filament/Loop type Glow Plugs take about a 13/16" wrench to remove them.)

If you have the Factory setup Pencil Type (you remove them with a 12mm wrench or socket) if one fails the rest of them still will work.

Harbor Freight sells Digital Meters for $5 or less when on sale.

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84 300D, 82 Volvo 244Gl Diesel

I have the older loop style.


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If you have a Test Light you could determine if you are getting Voltage to the Fuse Box. That would give you a good idea that the Relay is working.

If one of the Filaments is burned; causing an open circuit you could see that; but, would need to remove the Glow Plugs.

Because of my poor memory if I was removing that type of Glow Plugs you have I would take a pic of them or make a drawing of the connections before I remove them.

Some people stay with the old system; others who live in cold parts of the Country like to update to the adapter Pencil Type Glow Plugs. However, sometimes the original Glow Plug Relay does not work with the update. Better to read the DIY on that.

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84 300D, 82 Volvo 244Gl Diesel

I just read the how to on the diesel giant page for updating to the pencil plugs and he mentioned leaving the key in the on position. I had the radio on for about an hour this afternoon so I wonder if I fried a plug.


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did you leave the key in the run position for about an hour? or was it in the 1st position?

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Pretty sure it was on run...


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your GP relay was prolly stuck on and burned out a glowplug. Just gotta find out which one is burned out now.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Over lunch I brought my meter home and tested the plugs and the first one (#4) was bad. I already removed it and the filament is broken so it looks like that is the problem. I'm almost positive this happened because I left the key in the run position yesterday afternoon so i could listen to the radio while I cleaned the car out.

My next question is should I replace the plug insulators or just the plugs? I have toyed with the idea of going to the fast glow system but I'm confused as to weather or not I would need a new relay box. The Diesel Giant write up indicated I don't however some posts indicate I do.

Thoughts?

From what I have read for sure the year 1976 Relays will not work; there is several threads on that where 1976ers did not work.

After that it is hard to tell because with some models and years if you look up the Glow Plug Relay at a parts place there is sometimes 2 or 3 different Relays that were used on that year.

Also in the Factory Manual it has that if the Injector spray pattern is sloppy or there is a timing issue it can ruin the Filiment on an Injector.

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84 300D, 82 Volvo 244Gl Diesel

I think I'm just going to stay with the old loop plugs for now. This set has lasted for 34 years so why change now

got my plugs in this afternoon from fastlane (thanks Phil for the help!) and installed them this evening... I can't imagine how fast a car with the pencil plugs must start cause mine fired as soon as I bumped the starter