Afterglow and the Violet Wire - Page 6 - PeachParts Mercedes-Benz Forum

Bio300TDTdriver · #76 12-31-2006, 02:04 PM

Quote:

Originally Posted by H2O2

Well, the thread originator had the temerity to go and get himself banned, so he can't respond--what a jerk. I guess I'll stand in for the jerk and try to decipher his cryptic ramblings...

He found the relay in a wrecking yard, but you can also order one from your favorite vendor. I don't have a part number, but MB uses these relays extensively, so go look in your fusebox to see which has the corresponding terminal numbers and get the part number off of that one.

The 86 terminal is wired to the temp switch on the t-stat housing.

The 85 terminal is wired to a 12v keyed source (w/inline fuse).

The 87a terminal is wired to one side of the snipped violet wire.

The 30 terminal is wired to the other side of the snipped violet wire.

The 87 terminal is not used.

He snipped the violet wire approximately 2" back from the relay, which required trimming the harness cover a bit.

This is a very effective modification. Highly recommended.

Where is everyone getting the 12 volt keyed power from? What size inline fuse are you using?

Thanks,

Chris

Bio300TDTdriver · #77 01-01-2007, 08:20 PM

bump

Chris

Zeitgeist · #78 01-02-2007, 12:22 AM

I don't remember which fuse I used in the panel. But, I believe I just opened up the back of the fuse box and located a free slot on a keyed fuse (maybe #8 or #11?)...dunno. The inline fuse is an 8 amp.

redassag00 · #79 01-02-2007, 01:11 AM

Quote:

Originally Posted by gsxr

If you want the full factory afterglow setup on a 603, here's a link to a thread with details on how to do it, including photos, part numbers, etc. I've had this on my car for about 18 months and I love it.

http://www.***************/forum/showthread.php?t=398

The violet wire trick is free, but will reduce plug life somewhat compared to the factory afterglow setup (which varies afterglow time based on coolant temp).

Thanks Dave! I was told that this couldn't be done!

Bio300TDTdriver · #80 01-02-2007, 01:27 AM

Quote:

Originally Posted by Zeitgeist

I don't remember which fuse I used in the panel. But, I believe I just opened up the back of the fuse box and located a free slot on a keyed fuse (maybe #8 or #11?)...dunno. The inline fuse is an 8 amp.

#11 in my fuse box is not used so I'm going to test that for power when the key is on and use that one.

Thanks,

Chris

Haplo · #81 01-05-2007, 10:49 AM

This really sounds like a usefull mod to do on my car. As soon as it is delivered I will start working on it. Since it is getting cold around here, this is the time to do it. Cause if I understood right the setup is the same for my w123 300 TD (OM617) non turbo. Only have to find myself a thermo-switch. And if I won't find one I will be able to add that, since I did the same on an other car of mine..

Still one question left. Is 50 degr. (celcius) not a little hot to trigger the GP off?? Is the coolant heated over 50 deg. within 1 minute before the relay shuts itself off??

gsxr · #82 01-05-2007, 03:53 PM

Quote:

Originally Posted by Haplo

Still one question left. Is 50 degr. (celcius) not a little hot to trigger the GP off?? Is the coolant heated over 50 deg. within 1 minute before the relay shuts itself off??

The relay still shuts off 1 minute after the key was turned on, regardless of temperature. The 50°C setup simply disables the afterglow when temp is over 50°C, reverting to normal glow (plugs shut off when engine starts).

86Gray300SDL · #83 02-03-2007, 09:33 AM

If the purple wire goes to 12V when the engine is started then it could be used to power the NO relay? Right?

gsxr · #84 02-03-2007, 07:07 PM

I'm pretty sure the +12v is only present while the starter is engaged, but I'm not positive about that. I wouldn't try to use it to power the relay though.

#85 02-03-2007, 07:13 PM

It's just a wire to give the relay a reference voltage when the starter is engaged. It's not designed to carry current.

moonlite · #86 10-08-2007, 05:08 AM

Where does one get a thermo-switch that cuts in or out around 40 deg C?

I need one of these for a fuel filter heater as well.

siral3x · #87 11-15-2007, 09:20 PM

What wire collors do I need to cut for a 1985 om617 Turbo? There are 2 violet wires going to the GP relay! Which one?

gsxr · #88 11-16-2007, 11:09 AM

Don't cut either one. Open up the connector housing, and remove one at a time. If the first doesn't work, then you'll know it was the other one. Tape up the end and leave it there. That way you can easily put it back to stock (which may be preferable in the summer, to make your plugs last longer).

#89 11-16-2007, 11:27 AM

It's really easier to just buy one of these (you will get a real post-glow instead of just a few extra seconds):

http://www.***************/search/product.aspx?sid=wjb4fk55tq2x4uzquvbua2yo&makeid=800016@Mercedes&modelid=1193790@300DT&year=1985&cid=glow@glow&gid=7164@Glow%20Plug%20Kit

gsxr · #90 11-16-2007, 11:57 AM

Quote:

Originally Posted by Craig

It's really easier to just buy one of these (you will get a real post-glow instead of just a few extra seconds):

http://www.***************/search/product.aspx?sid=wjb4fk55tq2x4uzquvbua2yo&makeid=800016@Mercedes&modelid=1193790@300DT&year=1985&cid=glow@glow&gid=7164@Glow%20Plug%20Kit

I agree 100%. The proper, temperature-based afterglow relay is much preferred over the "violet wire" trick, especially now that glow Bosch/Beru plugs are nearing $20/each.