Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-20-2016, 10:05 PM
Registered User
 
Join Date: Jan 2009
Location: N.W. In.
Posts: 609
I'm bewildered

Yes I finally got all the fluids in and took care of some other last minute issues on this engine install I'm doing on 85 300 sd and I finally got to start it and I crank and crank and crank and can't get it to even sputter. Took notice real quick my glow plug light is not working. I checked all the plugs before install and they all worked. Checked them again with a 12 volt test light and they all had juice except the 5th one so I thought guess the 5th one went bad and was going to replace that one. I checked the wire feeding it for continuity and it was good along with all the 4 other wires. As I was trouble shooting at the glow plug relay box for power when I had the connector feeding the 5 glow plugs I noticed my light started working in the dash I thought well its working now put the connector back on feeding the glow plugs and then no light in the dash and no juice at any of the plugs. I go back to the box and wiggle the plug that has 4 wires on it I hear a click and now I got juice again and a light in the dash, as soon as I plug the 5 wire plug in feeding gp's everthing dead again. The only thing I think that may be happening is that when I put the engine in those wires in that harness got pinched really bad between a.c. and frame of car. I'm thinking I have to rip the g.p. harness out and see whats going on unless someone can enlighten me as to what is happening? Sure hope I can get this running tomorrow as it has been down over a month now.

Reply With Quote
  #2  
Old 09-20-2016, 10:12 PM
Registered User
 
Join Date: Sep 2001
Location: central Texas
Posts: 17,281
What car is this ?
Reply With Quote
  #3  
Old 09-20-2016, 10:45 PM
Registered User
 
Join Date: Jan 2009
Location: N.W. In.
Posts: 609
I posted its an 85 300sd 617 motor. I had all the wires unhooked even at the junction box but Im pretty sure I got them all back in the right spot. Car turns over good. Everytime I plug the glow plug harness in there is no juice to plugs I have to wiggle the plug that has the 4 wires in it I thinkit goes to the junction box on passenger side fenderwell I hear a click and I have power coming off the 5 prongs out of g.p. box but the minute I plug the g.p.'s in no power to the plugs kind of like something trips then when I wiggle the 4 wire small plug seems like it resets.
Reply With Quote
  #4  
Old 09-20-2016, 10:45 PM
Registered User
 
Join Date: Aug 2010
Location: Sacramento, CA
Posts: 3,115
You should measure 12 V at #5 glow-plug (terminal screw to gnd) whether the glow plug is good or not. If not, the wire to it or the glow plug relay is bad.

Both my 300D have started becoming erratic on lighting the dash lamp. I checked that all glow plugs are good (need 3 working to light). Even when not lit, the relay is usually on (measure 12 V and hear it click off after 20 sec). I swapped w/ a spare relay and no difference. Often, if I leave the switch in "run" for 5 sec & try again, the lamp lights. Haven't dug into the lamp feedback circuit yet. It does depend on a coolant temp sensor reading.
__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans
Reply With Quote
  #5  
Old 09-21-2016, 06:35 AM
Registered User
 
Join Date: Jan 2009
Location: N.W. In.
Posts: 609
Just checked this morning again I have 12.5 volts at the relay coming in and going out but as soon as I plug the harness in to carry voltage to glow plugs I have nothing at the plugs yesterday I had voltage to first 4 g.p.'s. Do you think problem is in relay or the wireing it did get pinched as I was putting engine in but I see no outside damage.
Reply With Quote
  #6  
Old 09-21-2016, 07:45 AM
Registered User
 
Join Date: Sep 2007
Location: Calgary Alberta Canada
Posts: 1,924
Unplug the glow plug wiring harness and the the glow plug relay. Check what ohms you get from each of the conductors from the plug with one test lead and the other test lead connected to engine ground and get back. You should have 5 reading one for each glow plug.
__________________
92 e300d2.5t
01 e320
05 cdi
85 chev c10
Reply With Quote
  #7  
Old 09-21-2016, 07:59 AM
Registered User
 
Join Date: Jan 2009
Location: N.W. In.
Posts: 609
Are you saying to unplug wires going to glow plugs and also the plug with the 4 wires on it that I think goes to te juntion box then take an ohms reading on the 5 prongs that feed the gp's?
Reply With Quote
  #8  
Old 09-21-2016, 08:25 AM
Registered User
 
Join Date: Sep 2007
Location: Calgary Alberta Canada
Posts: 1,924
Connector between glow plug relay and glow plugs.
__________________
92 e300d2.5t
01 e320
05 cdi
85 chev c10
Reply With Quote
  #9  
Old 09-21-2016, 09:17 AM
Registered User
 
Join Date: Jan 2009
Location: N.W. In.
Posts: 609
I just checked the ohms on each wire feeding glow plugs I got a reading of .2 ohms telling me there is no problems or breaks in the wires. Is there a way to check relay?
Reply With Quote
  #10  
Old 09-21-2016, 11:02 AM
Registered User
 
Join Date: Nov 2013
Location: San Mateo, CA
Posts: 1,120
From your description, it sounds like you have an intermittent electrical connection.

If you haven't done so already, unplug all the connections on the glowplug relay and treat with electrical contact cleaner.
Disconnect the battery beforehand.
Also remove and inspect the strip fuse.
They are known to develop hairline cracks that can cause your problem.

If the relay consistently engages after the above treatments and the car still fails to start...you may have lost prime and have air in the injector lines.
__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022
Reply With Quote
  #11  
Old 09-21-2016, 11:11 AM
sixto's Avatar
smoke gets in your eyes
 
Join Date: Jun 2000
Location: Eastern TN
Posts: 20,841
Does this relay have a fuse or a breaker? You've done everything I'd do before throwing a new relay at it.

Sixto
83 300SD
Reply With Quote
  #12  
Old 09-21-2016, 11:26 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,036
Quote:
Originally Posted by yuke View Post
I posted its an 85 300sd 617 motor. I had all the wires unhooked even at the junction box but Im pretty sure I got them all back in the right spot. Car turns over good. Everytime I plug the glow plug harness in there is no juice to plugs I have to wiggle the plug that has the 4 wires in it I thinkit goes to the junction box on passenger side fenderwell I hear a click and I have power coming off the 5 prongs out of g.p. box but the minute I plug the g.p.'s in no power to the plugs kind of like something trips then when I wiggle the 4 wire small plug seems like it resets.
This is on a W123 and the square Connector on the Glow Plug Relay

I don't know if the colors of the wires re the same on the 4 socket connector.

1) rd/bk (Black) ignition switch (Voltage goes thorugh this to turn on the Glow Plug Relay, if you cut the Wire and wired a push button Switch to it and your GP realy is still good you could use the button Switch to turn the Glow Plugs on and retain the feature that tuns the Glow Plugs on while the Engine is cranking bay way of the Purple Wire on a W123. I also believe the Glow Plug Light would still work if you do this.)

2) vi (Violet/Purple) On turbo models goes to a Wire Terminal/Junction block and mates with a White Wire coming up from the Starter Solenoid. When you Crank the Starter + Voltages goes through the White Wire to the Violet one and turns the Glow Plug Relay On. (You could disconnect this wire at the Terminal Block or the small Terminal at the Starter Solenoid and wire it to a push button Switch.)

3) blu/wt (Blue with white strip)glow indicator Light

4) br (Brown)ground
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #13  
Old 09-21-2016, 11:29 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,036
Quote:
Originally Posted by yuke View Post
Just checked this morning again I have 12.5 volts at the relay coming in and going out but as soon as I plug the harness in to carry voltage to glow plugs I have nothing at the plugs yesterday I had voltage to first 4 g.p.'s. Do you think problem is in relay or the wireing it did get pinched as I was putting engine in but I see no outside damage.
Apply you Volt Meter to the Battery and pug in the Glow Plut Connector and see if there is a drop in voltage at the Battery.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #14  
Old 09-21-2016, 11:31 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,036
Did you loosen some hard lines at the Injectors to see if you are getting fuel up to them?
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #15  
Old 09-21-2016, 11:57 AM
Rogviler's Avatar
Unpurist
 
Join Date: Apr 2011
Location: Colorado
Posts: 904
Interesting, yet another sudden case of a no-start...

This may or may not help, but I suddenly lost all glow awhile back and traced it to a bad ground. I decided to run its own short ground directly to a bolt nearby and it's been fine ever since. I agree that it's an intermittent wiring problem as far as the plugs go.

Quote:
Originally Posted by Diesel911 View Post
2) vi (Violet/Purple) On turbo models goes to a Wire Terminal/Junction block and mates with a White Wire coming up from the Starter Solenoid. When you Crank the Starter + Voltages goes through the White Wire to the Violet one and turns the Glow Plug Relay On.
Doesn't the violet wire turn the relay timer OFF? I see a lot of people modifying the connections (or unplugging the violet wire completely) so that the glow plug timer isn't interrupted once the starter cranks over and it glows for 30 seconds all the time (afterglow).

-Rog

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 06:46 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page