Help Please - I'm going Mad!

IBN

Active Member
Joined
Dec 15, 2006
Messages
76
Location
Northern France
Car
W129 300SL
Hi everyone - I hope somebody can offer me some advice because I'm going round in circles.

I own a R129 300 SL (1990 US Spec) which has been stuck in the Mercedes Dealer in Dieppe since 10 August. I won't go into the unhappy saga (I've already posted a thread on the matter) but I'll summarise for the sake of clarity.

Car went to dealer for annual service. Dealer broke key off in ignition lock. Took them ages to obtain new barrel. Eventually (12 November) I was told car was ready for collection. I said I would collect on 13 November.

On morning of 13 November, I received a call to say I couldn't collect because the car wouldn't start. Later I received another call to say I could collect because it was just a dirty contact. So off I went. I paid the bill (which was 1000 euros) and set off for home. Despite the bill, I was happy with the car (she was going better than ever before) BUT after 17 miles the car just died - No power (all warning lights came on) and she stopped .... in a very dangerous position and in heavy traffic. I was not happy!

The car would not restart, so I called out the breakdown service and got the it taken back to the dealer. I told the dealer to sort it out, they said that they were sorry and would get back to me.

As I haven't heard from the dealer, I rang them this morning and got the following response.

1. They still had not diagnosed the problem.
2. Their diagnostics machine doesn't work on old vehicles.
3. They don't have an auto-electrician who has experience of old vehicles.
4. Sometimes the car starts, then a few moments later it won't start.
5. When the car starts there is obviously current at the fuel pump but when it won't start there is no current at the pump.
6. They've tried a new fuel pump relay and say it makes no difference.
7. They don't know how long it's going to take to sort it out.
8. They don't think Mercedes France Customer Service will be able to help me.

I now just don't know what to do.

I had a similar non starting problem last christmas but it seemed to go away, and didn't mention it when the car was serviced - I suspect it may be an intermittant problem - Any Ideas?

The only other thing I can think of is .... I had recurring alarm problems (it kept going off at odd times) and read that it was likely to be caused by
the internal battery (inside the alarm) being dead. I also read that if you remove the unmarked fuse (in the boot fuse box) it would kill the alarm. I did this and it worked and everything else seemed to work ok - so I left it
out (disconnected) - Could this be causing the problem?

Any Suggestions?
Thanks
 

ash59fifty-uk

MB Enthusiast
Joined
Aug 9, 2015
Messages
3,816
Location
The shire
Car
C204 C63, VW Transporter
I remember your original post and it's a shame it's still not sorted

I may be way off the mark here, but as you mentioned the fuel pump...

I had a classic shape WRX with a fiddly alarm on it, in fact I also had an XR3i with a similar alarm. The immobilisers on both vehicles were routed to the fuel pump, current would go to it however when immobilised current would stop, unless immobiliser was turned off.

Both cars had a kill switch, well hidden ones. Impreza had a sequence and the escort just a simple switch that was so easy to knock it was unreal. Anyway... You haven't got a hidden switch anywhere in the car have you? The Impreza one I didn't even know about till similar happened in a garage and we tried to diagnose it

Ashley
 

richard

Authorised Forum Sponsor
SUPPORTER
Joined
Jun 10, 2002
Messages
6,297
Location
Berkshire, UK
Car
MY04 SL55, MY18 GLC63s
I would be very suspicious of the alarm's immobiliser function. UK cars of that age got a dealer fitted alarm, I don't know what would be on yours though.

Richard
 
OP
OP
IBN

IBN

Active Member
Joined
Dec 15, 2006
Messages
76
Location
Northern France
Car
W129 300SL
Still the saga continues .... just spoken to the dealer and was told the problem is with the fuel pump relay and that it would cost 800 euros to replace (I nearly fell off my chair!). I said "what the two little boxes in the fuse box", he said no not those ..the big one on the other side that controls the two fuel pumps. Not sure what he means (my french isn't good with technical things) Anyone any idea what he's talking about and if so whether 800 euros (£600 ish) is reasonable? Thanks
 

neilrr

MB Enthusiast
Joined
Jul 20, 2004
Messages
6,541
Car
Various.
IBN,

Is it a 300SL or a 300SL-24?

What's the VIN?

Does the FPR look like the big one on the left? If yes, I have one. If it isn't that component can you tell us the part # of the FPR you need?

 
Last edited:

bolide

MB Enthusiast
Joined
Oct 8, 2005
Messages
3,724
Location
Brighton
Car
BMW E39 525 Diesel Touring
I'd want to know what happens if they fit the new module and the fault persists. If, by their own admission, they can't diagnose the problem properly, then what's to say their proposed fix will do the job?

What's the part number of the unit they want to replace? If it's the EZL unit they are expensive but they are also commonly found in breakers yards

The EZL is on the inner wing and is the ignition controller. It normally has a round diagnostic port covered in a cap

Nick Froome
 

jonnyboy

MB Enthusiast
Joined
Nov 27, 2005
Messages
2,562
Location
Camberley, Surrey
Car
1991 sl300-24 project,s124 280,w115 no interior, w108 project no engine
I may have an EZL unit in the garage off a 24v - post up the part number.
 

Dec

MB Enthusiast
Joined
Jul 28, 2004
Messages
4,475
Car
C180,A.
What kind of remote fobs do you use or have you used in the past to lock and unlock the car?

Dec

 

neilrr

MB Enthusiast
Joined
Jul 20, 2004
Messages
6,541
Car
Various.
It won't be the EZL. For a 300-24 engine they are a lot more than 800 Euros new.
 

GadgetBoy

Active Member
Joined
Aug 19, 2011
Messages
142
Location
Belfast, N. Ireland
Car
ML320 and CLK200K Cabrio
"Car went to dealer for annual service."

Surely it's up to them to return the car to you in the condition you gave it to them, ie, working!
 

jaymanek

Authorised Forum Sponsor
SUPPORTER
Joined
Nov 29, 2002
Messages
16,415
Location
Nuneaton Warwickshire
Car
Lots of Mercedes!
Firstly the immobiliser on the alarm has to be completely ruled out.

On my w124 with same system I went around in circles. Same issue, intermittent none start and I also found no fuel pump feed when this happened.

I removed immobiliser but fault persisted.

On the 24v models the fuel pump relay is part of that Mas module as neil points out above. They are expensive new and according to my dealer, they aren't sold very often - in my experience this tells you these don't commonly fail and to look elsewhere.
I went through 4 used Ebay ones before I concluded that 4 of them couldn't have the same fault.
This went on for a while due to intermittent nature of issue.

Then I found that the old alarm system had a secondary immobiliser. Earlier I had bypassed what I thought was the immobiliser but that was the "starter immobiliser." So I found this second immobiliser wiring, which controlled fuel pumps, and removed it. Never been a problem since.

MB will have little diagnostic capability on this. They will go through a parts swapping exercise until it works.

I think you need to push them to check alarm first and then ask them if they will still charge for the new fuel pump relay if it doesn't work.
 
OP
OP
IBN

IBN

Active Member
Joined
Dec 15, 2006
Messages
76
Location
Northern France
Car
W129 300SL
Hi Guys

Thank you for all your replies. I'll ring them in the morning and get the part number.

The car is a 1990 US Spec. 300SL (so I think VIN Numbers & Chassis Numbers are
sometimes considered strange) but VIN on the Data Sheet in back of Service Book is as follows:

WDBFA61EXLF007168

With regards to which model it is I've always thought that it is a 300SL BUT the Data Sheet in the back of the Service Book says it is a 300 SL-24

The comment regarding getting the car back in the same state as it was when it went into the dealers is perfectly correct. Problem is my french isn't good enough to argue with the buXXers & Mercedes France don't want to know - I've tried to involve them but all they say is the dealer says the problems are down to usage and they always
believe what the dealer tells them (so tough luck).

The keys I use are both single button flip keys like the 1994 one shown on Dec's post.

Thanks again
Ian
 

WG M-B

Auhorised Forum Sponsor
SUPPORTER
Joined
May 26, 2011
Messages
1,897
Location
N/W london
Car
C63 Wagon in black
I think when the car cuts out someone needs to see if you are losing spark, or fuel.
Then fault find from there. Old alarm systems are a headache as pointed out, as are ezl units, mas relays etc etc. I personally doubt it's an ezl unit as heat and summer would cause them to fail commonly.
I'd say it's the mas relay failing myself.
It is repairable.
 
OP
OP
IBN

IBN

Active Member
Joined
Dec 15, 2006
Messages
76
Location
Northern France
Car
W129 300SL
Thanks for the tip. I'll have to put your posting through "Google Translate" and hopefully I can get them to understand!
 
OP
OP
IBN

IBN

Active Member
Joined
Dec 15, 2006
Messages
76
Location
Northern France
Car
W129 300SL
Thank
I'm going to be a busy boy tomorrow!
 

Dec

MB Enthusiast
Joined
Jul 28, 2004
Messages
4,475
Car
C180,A.
I the “plip” a remote fob separate from the flip out key in my picture?

Dec
 

DSB SL AMG

MB Enthusiast
Joined
Jan 28, 2010
Messages
1,598
Location
Cheshire
Car
300SL (R129 1992 pre-facelift), Volvo V70 SE D5 Auto Geartronic
Diagnostics is primitive on early R129 upto around 1995/6, STAR cannot be plugged in...so in certain cases garages will try component swap and hope with complex intermittent issues, key point is agreeing up front what you are willing to pay for in terms of success...which due to language barrier is going to be hard in your case, maybe go visit and take an interpreter friend with you so you can clarify with your MB stealer...
 

neilrr

MB Enthusiast
Joined
Jul 20, 2004
Messages
6,541
Car
Various.
IBN,

It is a 300SL-24.

Below is the page from EPC showing (most of) the relays on your car.

 

Dec

MB Enthusiast
Joined
Jul 28, 2004
Messages
4,475
Car
C180,A.
You seem to have, in the past, had trouble with the alarm as it was faulty and it used a plip.
See… http://www.mbclub.co.uk/forums/electronics/132039-w129-fed-up-same-old-electrical-problems.html

My theory is that the car alarm is dormant (disarmed) and it did once have a plip which is now no longer in use.
When the car was being serviced, the car battery was disconnected and as soon as the battery was re connected the dormant (faulty?) car alarm rearmed itself, which is normal for alarms of that era.

Could this explain why the French can’t get the bottom of the problem because of a possible faulty alarm and a missing plip needed to disarm the alarm?

Just my active imagination going on here.

Dec
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom