Question about glow plug relays - PeachParts Mercedes-Benz Forum

mouramen · #1 05-03-2009, 07:10 AM

Hi gents,

Been tracing the cause for my bad cold start, I think it's diesel injection (because ut started when I tried bio-diesel) related but I'm focusing on the glowing part for now!
Se pic attached, the bottom one is the relay from my merc and the upper one is from my former w201.
Can I just swap them out?
They've some differences, the one from the w201 (more recent) doesn't have the 30AMP fuse and the plug is using one more contact that reads "T".
All the other numbers on both plugs are ok!
What do u think?

aaa · #2 05-03-2009, 07:28 AM

T is probably for temperature. Some of the relays connect to a temperature sensor and use it to determine how long to light up the glow light. I don't think it affects the actual glowplug operation though (you could just ignore the light and glow as long as you want).

mouramen · #3 05-03-2009, 04:19 PM

Just swapped them out, cranked and it started better, but I'll see in the morning.
I'm just worried about the fuse, this new one doesn´t have one...

compress ignite · #4 05-03-2009, 06:28 PM

The Pre-glow relay without the 80 Amp fuse has an internal Electronic "Failsafe"
that dis-engages the relay in case of a short or other electrical anomaly.
It's a pretty neat little device,only offered on certain year/model chassis.

aaa,
Is correct the "T" pin is for measuring Temperature,so that the PGR may
adjust "Glowing" times.

If you're as AR about EC fires as I am you could put an 80 Amp fuse IN-Line
on the positive power feed wire to the Pre-glow Relay with no harm.

(Motto: You can NEVER have Too Many: Fuses,Fire Extinguishers,Batteries.OR
Too large a Gauge Wire/Cable.)
(At Sea:If you think your batteries are Too Big ,get a larger Craft AND THEN
Get even Larger Batteries!)

mouramen · #5 05-03-2009, 06:41 PM

Quote:

Originally Posted by compress ignite

The Pre-glow relay without the 80 Amp fuse has an internal Electronic "Failsafe"
that dis-engages the relay in case of a short or other electrical anomaly.
It's a pretty neat little device,only offered on certain year/model chassis.

aaa,
Is correct the "T" pin is for measuring Temperature,so that the PGR may
adjust "Glowing" times.

If you're as AR about EC fires as I am you could put an 80 Amp fuse IN-Line
on the positive power feed wire to the Pre-glow Relay with no harm.

(Motto: You can NEVER have Too Many: Fuses,Fire Extinguishers,Batteries.OR
Too large a Gauge Wire/Cable.)
(At Sea:If you think your batteries are Too Big ,get a larger Craft AND THEN
Get even Larger Batteries!)

So i'll be fine...

Let's see in the morning, good thing I kept some stuff from the w201!