Mercedes 560 SEC 1988...Power Problem - PeachParts Mercedes-Benz Forum

#1 09-19-2006, 01:47 AM

Hi there:
This is my first post. I have an 1988 Mercedes 560 SEC which I purchased about a year ago. I knew what I was going to get into with an older vehicle but I was prepared to keep it on the road. I have replaced a number of parts..spent about 6000 dollars over the year. I drive this car every day...she got me to Florida and back without any trouble last year even though she now has almost 500,000 k on her.
I have a question. Over the past month or so..after getting the ignition changed.computer chip..and fuel filter, etc...my mechanic cannot find the solution to the following problem..... occasionaly while travelling along..the car all of a sudden cuts out..all power is lost. I find that I simply have to return the key to the starting position and then back and the vehicle resumes where it left off. So I do not have to restart it in neutral while travelling. The mechanic where I purchased the used vehicle has been in business 45 years (all used Mercedes) and couldn't fix the problem. He then suggested that I go to an actual Mercedes Benz dealership which I did. The service guy at MB asked me if I had a voltage overload protection relay in the car. I didn't know but upon checking with the parts counter...they told me what to get. The service guy said that this was the only thing he could think of that could shut the power down on the car. Fair enough...however I checked on ebay and was able to get two of the relays and they are now on the way..(much less than the dealer wanted). I really hope that this fixes the problem. By the way the MB dealership parts guy had given me the wrong part number...the fellow who sold me the part told me where to look to find the part. I simply then took it out and looked at the number and checked the prongs..7 and was then able to get the correct part. Now at least when I do get the parts I can install it myself..that should save me some money.
Does anyone else have any suggestions while I am waiting for these relays..as to what could have caused this problem..or any other solutions for me?
Also where is the best place to get parts for the exhaust? I can try ebay motors..and there are some wholesalers. I prefer Original Equipment Manufacturer parts and do not want to start using any others? Any suggestions on whre to buy in general. I am in Canada and would need them shipped to Burlington Ontario.

GreginTO

david s poole · #2 09-19-2006, 10:39 AM

when the car shuts down is it an immediate stop or over 2 or 3 secs.if the first i would replace the pickup from the flywheel to the ignition unit.if the second it will be fuel pump relay or related electronics[ovp relay].

autozen · #3 09-19-2006, 10:47 AM

If I'm reading your post correctly, it sounds like the ignition switch at the back of the switch assembly is failing. Unusual but possible.

#4 09-19-2006, 11:02 PM

Hi guys...Thank you for the replys regarding my power problem. I will check to see if it is the flywheel...or the switch etc..and let everyone know the result..as soon as I can get the car into the mechanic..

All the best,

Gregin TO

#5 09-22-2006, 10:28 PM

The overload voltage protection relays that I ordered finally came in from the U.S. I popped one of the 7 prong units in and I noticed instantly a vast difference in power and in all running equipment such as air, heat etc....
Obviously my unit that was in it..was slowly failing. The car started easiere and performed much better...a very important piece of equipment that relay...
My Merc goes into the shop on Monday to get some rattles underneath the vehicle taken care of (heat shield) and to see why I have so much air coming out..could be the muffler but last time we checked the mufflers they were ok...could be a hole in the connecting pipe...We shall see.

Skeezix · #6 01-01-2008, 10:26 PM

My "Hetta" is a 10/86 560 SEC 126.045 ... she cut out when I had run the seat heaters and head lamps and etc. I had her towed home and checked the fuel pump in AM then she started like always... Right rear window has ceased to function and generally she has a 'tired' feel to her.
Certainly not reliable transport at this time .
My CD with service info shows no relay but i spotted one on line... any assistance will be welcome
Rob Klyver
robertklyver@yahoo.com

Quote:

Originally Posted by GreginTO

The overload voltage protection relays that I ordered finally came in from the U.S. I popped one of the 7 prong units in and I noticed instantly a vast difference in power and in all running equipment such as air, heat etc....
Obviously my unit that was in it..was slowly failing. The car started easiere and performed much better...a very important piece of equipment that relay...
My Merc goes into the shop on Monday to get some rattles underneath the vehicle taken care of (heat shield) and to see why I have so much air coming out..could be the muffler but last time we checked the mufflers they were ok...could be a hole in the connecting pipe...We shall see.