Glow plug Relay Upgrade - PeachParts Mercedes-Benz Forum

Kyle Blackmore · #1 10-27-2003, 09:22 PM

Is it possible to adapt a new Bosch preglow kit to work with my older pencil type GP's. The kit come with a new style relay that glows for up to 3 minutes , price on this site including 4 gp's is $102 . I finally found a used relay for my '80 but he wants $110 for it. Whadda you think ?

kerry · #2 10-27-2003, 09:28 PM

I was under the impression that the pencil type were the new ones and the loop style were the old ones? Am I mistaken?

Kyle Blackmore · #3 10-27-2003, 09:50 PM

No Kerry you are correct but 1980 was a change over year and used a unique relay. I believe the connectors are different but the only major change I can see on the schematics is circuit 50 gets power from the starter/AC relay in '80 and from the starter lockout switch in '81.

gsxr · #4 10-28-2003, 03:41 PM

If you upgrade to an "afterglow" style relay, you'll need the afterglow rated pencil plugs... standard pencil plugs will burn out much sooner. Usually the kits come with the afterglow relay AND the plugs. I think you could probably tweak the wiring for your '80 if required?

Kyle Blackmore · #5 10-28-2003, 10:09 PM

Hi Dave, I didn't know the gp's are different , I won't use my spare then

, oh well.I'm going to go ahead and adapt to the new kit , I know I have to pull the connectors apart and either move the wires in the original connectors or adapt to newer style connectors . I like the idea of the afterglow , and the price is right also , an original style Beru is double the price w/o gp's

.

gsxr · #6 10-29-2003, 12:13 AM

On later 123's, you can do a "poor man's afterglow" by removing one wire from the connector at the relay. That's the wire that turns them off when the ignition key is released after cranking. So, they will stay on to the GP relay's time limit (30 seconds or so, depending on ambient temp). I did this last winter on my '84, but put it back to normal when it warmed up in springtime, to save my "standard" plugs. The engine is eerily quiet for those first 30 seconds with the GP's on and the engine running! I think it's the purple wire on most cars - just remove from the plastic connector housing, bend back out of the way & tape it off - don't cut anything. The standard GP's will work fine, they'll just have a shorter life. How much shorter? I'm not sure - maybe half or less. Later model MB's had really nifty afterglow that used an external coolant sensor in the cylinder head, and it would not glow after starting with the engine warm - further saving the plugs. The "poor man" method above will do the full 30 seconds (or 60, or whatever) at EVERY start, which is quite a bit if you're running around town. I'm not an expert on the subject so I hope someone else who has messed with these personally can chime in. I know more about the later OM60x setups.

#7 10-31-2003, 12:44 AM

GSXR & Group,

I'be been fussing with two ideas. I've been thinking for a while that it would be nice to have a "remote glow" option, much like a car alarm remote start feature. Maybe this only appeals to me, as I'm stuck riding a bus back to parking, and thus my car every day, and I think it would be damn nice on this 603 motor in the winter, to be able to hit a key fob remote (as I'm waiting for the herd to exit the bus,) and activate a long glow plug cycle, so as soon as I'm in the car, I can just turn the key. I definitely want to penny tech this idea, hopefully buying someones otherwise fragged/cheap alarm, as this is the only feature I want/need.

As far as a the afterglow, I was thinking of opening up another spot in the center switch cluster, and adding an unmarked OEM switch, so that I could tap into the "purple" wire, but have a clean switch installation to disable it when I don't see the need for the afterglow. (To take it a step further, I would like to use a rocker switch that would be illuminated during the glow cycle, just as a reminder, though this feature may not be worth the effort.)

Anyone using the Bosch afterglow kit on a 603? I'm do for new G.P's and I'm considering the Bosch system. I think I would prefer to disable the the afterglow in all but the coldest months, as it seems this would give the best of both worlds, the afterglow when needed, without dramatically shorter glow plug life.

Thoughts, Ideas, reactions?

Stevo · #8 10-31-2003, 11:28 AM

You guys could eliminate all this fuss and expense concerning relays and after glow systems. A couple of years ago I needed a new relay for my "79" but didnt have the $ so I installed a 15 amp push button switch. The dash light is wired in, push the button the light comes on, the GPs get juice. I went to the new style plugs and added a solenoid (Ford, $16.00) and a 80 amp fuse. The push button is under the dash on the left so I can push the button with my left hand and turn the key with my right. I can glow, after glow, or not glow, the control is mine, its a straight forward system with little to go wrong.

Kyle Blackmore · #9 11-02-2003, 02:25 PM

Mack- the kit from Bosch will work on 123's after 8/'80 , all 126's , 124's up to 1/'89, 201's up to 1/'89 , G460/461's up to 1/'89 , 207's,209's,307's,309's,407's,409's and 507's after 9/'82. Bosch part number is 0 250 201 953. The kit includes 4 gp's and the relay.A simple replacement for all those models.
Stevo- if I was the only one driving the turtle I would do a 'field repair' like you describe , but since the wife's car is hibernating for the winter a 'blonde-proof' solution works best

.
The relay is in now and works perfectly , my lite comes on and as soon as it's off the turtle starts like a gas engine ,

.Bring on the winter !

gsxr · #10 11-03-2003, 01:59 PM

Mack - I totally forgot about that. Yes, you can add a toggle switch in the dash, connected to the purple wire, to manually turn off the glow if you want (for warm starts). Some other folks did this last winter, I remember the messages from the MBZ.org email list.

Rich1Merc · #11 10-29-2006, 09:22 PM

I just recieved my 0 250 210 955 Bosch Duratherm glow plug kit for my 1981 240D. The only problem Autoparts warehouse sent the wrong glowplugs. I'll keep the relay but I need to order upgrade glowplugs.
What is the part number for these> They have the 10mm dia. shaft. the ones they sent have 18mm shaft.
Thanks,
Rich

Also, how do I do this upgrade to my 1976 300D? I think it has the loop GPS. do they make the newer pencil type for the 300D?
Thanks again.

babyjames · #12 10-29-2006, 10:20 PM

You just need one more with the 18mm threads, and you're golden. You can re-wire the plugs themselves (parallel vs. series, do a search) and use the pencil-type plugs with the existing relay setup.

Jay.

myke_w · #13 12-26-2007, 09:19 PM

sorry for the partial thread jack,
regarding the upgrade, does anyone have a good wiring diagram for the 5 cyl cars? I need specifically to find out what the original wires going into the relay are for in the 79 cd we're working on..

any help is appreciated

Diesel911 · #14 12-27-2007, 12:58 AM

Quote:

Originally Posted by Stevo

You guys could eliminate all this fuss and expense concerning relays and after glow systems. A couple of years ago I needed a new relay for my "79" but didnt have the $ so I installed a 15 amp push button switch. The dash light is wired in, push the button the light comes on, the GPs get juice. I went to the new style plugs and added a solenoid (Ford, $16.00) and a 80 amp fuse. The push button is under the dash on the left so I can push the button with my left hand and turn the key with my right. I can glow, after glow, or not glow, the control is mine, its a straight forward system with little to go wrong.

I did the same with the solenoid and push button switch on my 6 cyl 82 Volvo diesel way back in 96. It is simple, cheap, and it works.
I have replaced several glow plugs since then but do not feel it has been exccesive. But, the winters are not cold where I am in CA.

Stevo · #15 12-27-2007, 11:14 AM

Quote:

Originally Posted by Diesel911

I did the same with the solenoid and push button switch on my 6 cyl 82 Volvo diesel way back in 96. It is simple, cheap, and it works.
I have replaced several glow plugs since then but do not feel it has been exccesive. But, the winters are not cold where I am in CA.

I am still pleased with my system, sometimes its a little hard to explain if someone borrows the car but that doesn't happen often. The only thing I will do different on the next one, is use a solenoid rated for "continuous" service. Someone mentioned that might be a better choice than just a starter solenoid.