• The Forums are now open to new registrations, adverts are also being de-tuned.

W124 300D '89, non starter

N

nickct

New Member
Joined
Oct 14, 2007
Messages
6
Hi all,

I've had my 300D auto a few years now and it has been uber reliable. I joined this forum a few weeks ago and this is my first post. I must have known that I was going to need advice. I would appreciate some help, any help

2 days ago the car would not start, these are the symptoms:
No instrument warning lights when Ign. is on
No indicators
No horn
Side and headlights are OK
Engine turns over fine
Radio works in usual Ign. key positions
All the fuses in the box under the bonnet are OK
I've reseated the relay modules that are behind the fuse box

I am guessing that this is a simple fault but the Haynes Manual that I have does not have a wiring diagram for the 300 D

Hoping some of you Gurus out there can help me

Many thanks

Nick
 
Try the OVP relay. The can cause all sorts of problems.
 
Please excuse my ignorance, but what and where is the OVP relay?

Nick
 
The engine turns over but doesn't start? That's almost impossible to achieve with a diesel

The lack of dash lights suggests there's a fault but I can't see how this is related to the engine not starting - unless there's an immobiliser, or an electric non-return valve in the fuel system

I am not 100% convinced there's an OVP in an early diesel but have a look anyway

Assuming there's no immobiliser or fuel shut-off my best guess is that it's not starting due to an air leak and that the dash light failure is an unrelated fault

Nick Froome
www.w124.co.uk
 
Last edited:
119 in the link i the OVP relay I feel it could be the ign switch


There is a fuse on top of the relay there should be 12v on any pin 87 do check the fuse.

A voltmeter on the ignition switch would also prove the point
 
bolide said:
The engine turns over but doesn't start? That's almost impossible to achieve with a diesel

The lack of dash lights suggests there's a fault but I can't see how this is related to the engine not starting - unless there's an immobiliser, or an electric non-return valve in the fuel system

I am not 100% convinced there's an OVP in an early diesel but have a look anyway

Assuming there's no immobilser or fuel shut-off my best guess is that it's not starting due to an air leak and that the dash light failure is an unrelated fault

Nick Froome
www.w124.co.uk
Click to expand...

Nick if no power to fuel pump it would not start, this is fed from the ignition switch, as is all the other missing voltages
 
WOW, thanks for all the replies so far.......

The engine turns over but does not start, this was when its cold so I think the reason might be that there is no power to the glow plugs, certainly no glow plug light...................

The ignition swithch seems OK in so far as the is life in each position of the switch, ie the radio works in each position and goes off in between switch positions..............

What and where is the OVP relay?

Thanks all

Nick
 
nickct said:
WOW, thanks for all the replies so far.......

The engine turns over but does not start, this was when its cold so I think the reason might be that there is no power to the glow plugs, certainly no glow plug light...................

The ignition swithch seems OK in so far as the is life in each position of the switch, ie the radio works in each position and goes off in between switch positions..............

What and where is the OVP relay?

Thanks all

Nick
Click to expand...
sorry I forgot the link for my earlier post
http://www.detali.ru/cat/oem_mb2.as...GM=717.430&CT=F&cat=501&SID=54&SGR=040&SGN=03
 
One thing is for sure,that is you have no power going to the fuse box that houses the N10 relay, that is also the one in the link
 
Hi

A 1989 124 diesel has a vacuum operated stop solenoid. It does not need power to make it run. It needs power to the heater plugs. Try putting a HEAVY cable to a couple of the heater plugs to see if she makes any attempt to start.


230K
 
Malcolm,

thanks for the link, that is one Mother Russian website. I put my Vin # in and all sorts of stuff came up................

Another symptom.......... the elec windows work as do the wipers

Nick
 
Ignition switch.

Thats where my money is.

Is the battery good?

Are the earth staps ok?
 
The fuel pump is mechanical. The fuel shutoff is pneumatic

Tell me how it doesn't start if it turns over...

Even with no power to the glow plugs it should start in the end assuming it's not freezing cold

I think it's ignition switch as well...

Nick Froome
www.w124.co.uk
 
Last edited:
#122 fuse inside top of RELAY #119

See RU schematic
Does it not show a fuse designated #122 inside the top of the OVP relay#119 ?
(I love fuses and automatic resettable breakers...especially SOME of the
Mercedes ones)

If the starter turns the engine over at sufficient speed (assuming you have fuel to the injectors)
only two things would stop the engine starting...1.lack of functional glow plugs (turn key to start
and check voltage to each glow plug during start cycle...except you are not getting a glow light
your dash...I think the lack of power to the glow system is your symptom...If you have a block
heater electric plug[male plug somewhere on or near the front of the car],plug it in for a couple
of hours to warm up the engine and then try to start...if ignition occurs the glow system is your
problem.)
2.Malfunction of the vacuum operated shut off on the back side of the injection pump...
although, if the rubber diaphragm inside the shut off fails it would prevent you shutting off the engine(and you would have to use the mechanical shut off on the side of the I.P.) anything
is possible [Mr. Murphy]

I had a 300SD that would not start due to the glow system fuse having a hairline crack
(invisible) After NA MB roadside assistance telephone alerted me to the possibility,I found
and inspected the fuse ...sure enough under a magnifying glass the crack showed.The
solution for me that day was an 100Ft. extension cord plugged into my block heater for
enough time to warm the engine up to operating temperature. Then I drove to the dealer
and bought two new fuses for less than $2.00 U.S.
In their helpful assistance the roadside gentlemen at NA MB reminded me that repeated cranking without starting would "wash down" the cylinder sidewalls with unburned diesel
diluting the motor oils assistance in sealing the rings against the sidewalls.(compression
loss)

I'm out on a limb here , but I believe your problem is either a fuse/relay or the ignition
switch as mentioned by earlier posters.
 
Last edited:
You must log in or register to reply here.

Users who are viewing this thread

Total: 1 (members: 0, guests: 1)

Similar threads

A
W204 C250cgi auto box failure and The French
Replies
0
Views
330
alexar
A
P
No Crank 2017 Sprinter w906
Replies
0
Views
150
Paulky67
P
G
A small help needed with W124
Replies
1
Views
239
Smiley
S
D
W124 300CE 24 non runner
2 3
Replies
56
Views
4K
Dimitris1969
D
H
Help diagnosing start issues '89 300CE M103
Replies
8
Views
1K
optimusprime
optimusprime
Back
Top Bottom