Ernest Jones

Since I'm new here, I'm going to throw this out there and never explain again about that "new part same problem issue" and my favorite of all is,
"My check engine light came on", which has never come out of my mouth.

My latest success story is a friend took my advice about his motorcycle that had sat inoperable for several years. Every electrical problem imaginable, a laundry list, unsalvageable pile of iron. I caught him before he ordered a list of parts. Bike cranks right up purrs now and not one light anywhere malfunctions and not one new part was purchased.

Words that have never come out of my mouth, "My check engine light came on..." Driving in swamping, puddled, torrential rain, wetter than wet soaked motor, multiple blizzards in mad weather, scare you to death weather if your car stalls and they do stall in blizzards. Main reason people are scared to drive in blizzards is cars will stall out and no one else is around. Smooth idle all day on my vehicles in all of these conditions. No codes thrown to date on one owner SUV; age 16 with 135,000 miles. Original starter, alternator, fuses, relays, sensors and all other original wiring components. My point being, it was the maintenance I did and not luck.

Electrical System Maintenance Procedure

Step (1) Avoid excessive rain/inclement weather driving and avoid heavy handed spraying with water hose jet nozzles every time the car is washed. My preference is low flow rinsing to clean with liquid waxes only, soap only if very dirty and greasy. If the following steps have been performed, this water encroachment can be mitigated. Say it with me folks, "Nothing electronic works well when wet. Wet circuitry is bad each and every day."

Step (2) Use proper safety equipment. Eye protection. Disposable latex gloves if you care about your hands. Cloth rags that do not create lint are helpful.

Step (3) Disconnect the negative battery terminal

Step (4) Identify each and every harness connection you are comfortable reaching and research how each coupling you see was designed to be released so you will not cause any damage

Step (5) Get your can of Electrical Contact Cleaner. Typically, only older weathered circuits need a very light spray, use spray cleaner sparingly and protect over spray with a small rag. Almost new connections can have oxidation as well and be unable to maintain 100% contact. Electrical connectors can and do drop below 100% for many reasons. The main 2 reasons are either loose/bent contact surfaces or dirt and corrosion/oxidation. If any electrical engineers want to go into specifics on sine wave interruptions at the hertz level for both smooth wave and pulse width modulated wave spikes, then more validation on the importance of dry and well connected circuitry is welcome.

Step (6) Get your tube of Dielectric Tune-Up Grease. Use sparingly on any plug/contact on the vehicle and never use dielectric grease on your battery, Negative (-) ground contacts or Positive (+) lead at the car power block. If you are not sure what I mean, just keep the grease off of anything with large gauge wire, battery side 12V high amp circuits create too much high potential sparking. That does not mean you cannot use it there, you can put it on those battery post connector sparingly. If you grease them excessively on the battery post, put a warning label on your battery "Do not connect this end last when jumping - Fire Hazzard, coating is flammable."


That is all there is to it. Doing this will make you a believer.
I've have never blown a fuse and that is not luck, no water has ever shorted in my system because I greased every contact about 15 years ago. Remember also, the more age a weathered car has, the more corroded connections in places you don't know exist. It is not practical to do every connector except when built, During any service on old or new cars that exposed hidden connections, ignoring this service quick step is almost sacrilegious in my book.

This procedure should also supersede any diagnostic code interpretations or part replacement is circuit subsystems. Remember, a code is nothing more than a pointer to wires in a vehicle. I will admit some parts can and do fail just not as you are led to believe. That brand new thingamajig that your swore fixed your problem when you "plugged it in" actually made the problem go away as a result of disturbing weak contacts during removal and reinstall, albeit temporarily in many cases.

If I helped just one person, it was worth writing this up.
Ernest Jones

PS, If you find this helpful and want to copy and paste this in other enthusiast forums, feel free to do so.

biker349

thanks.

Ernest Jones

Welcome.

There are truth in advertising laws in the US.
IMHO, car manufactures should be required to add a new warning label on the interiors that read, "THIS VEHICLE IS NOT WATER RESISTANT"

And this is why I will not drive my W129 in the rain, ever
The previous owner obviously did not drive it in the rain as is evident by the engine and chassis condition.

Russell Ormerod

Wow so every every electrical problem is due to water or moisture in plugs even the cause of engine lamps to come on. I must have been replacing parts and doing sw updates for nothing all these years.

Ernest Jones

Some components do fail. However, I have tested dozens that other pulled off and replaced only to find nothing wrong with them.

It actually makes me angry so few people are made aware how corrosion disrupts electrical components. It is no wonder expensive audio equipment has gold plated connectors or solder is used to join wires. Put some cheap stereo wires on a high end amplifier and speakers, that crappy noise is due to poor contact.

Another example, install a new coil pack, this is a high frequency pulse with modulated circuit. New, they actually come coated with dielectric grease, at least most do. But, install it dry and only drive it on bright sunny days, it might last for a while. But, run that dry coil pack in rain day after day and it will blow the leads in no time.

Never replace a part until you have cleaned the harness connections.

I forgot my favorite example. Boat owners, salt water use specifically. I have looked at older sailboats and while the boat might be beautiful, everything in the electrical system is always a nightmare... Can you guess why that is? LOL

Russell Ormerod

It's true what you say regarding poor connections. But I can tell you it seldom happens on a mercedes. Only circuits that are often affected by poor contacts are SRS circuits. But you seem to believe that 99 percent of issues relate to poor contacts. I don't agree with that. I have scanned and repaired thousands of engine check light issues and very few if any related to poor contacts. Poor plugs contacts usually occur on a mercedes when people stick incorrect probes into plugs and spread the terminals. So. Although I agree with you that good connections are critical to correct circuit function they definitely not the main cause of problems. I am only referring to mercedes benz cars here. But good luck with your contact cleaner and dielectric grease venture. Let us know how it goes.

Ernest Jones

If you patronize me, then you are also patronizing everybody.

Listen son, troubleshooting million dollar advanced computer system, integrating those systems, compiling and distributing client server database web, insane integration. Over your head integration. You were the egg head that ate crow when I found the loose wire.

In other words, stay out of my thread unless you have something positive to add. And your comment is all you need to say sir.

Russell Ormerod

There is No need to be rude here! Who cares about your million dollar computer systems and database integration. It's has nothing to do with mercedes benz repair. This is a mercedes benz forum and I am stating my opinion based on my experience with repair So stop bragging with useless info. Cheers

Ernest Jones

You patronize me and then think adding a "no need to be rude" comment validates anything you have to add?
I'm pretty sure your CV starts and ends with high school education, some tech training who knows what else.
My CV includes a degree in Microbiology. That only took 3.5 years, couldn't get the classes fast enough to do it in 3. Those million dollar computer systems? Yeah, let's go there since you so quickly dismissed it to try and discredit me. Research this term, Configuration Manager. While I was distributing software and database code used by most of the US government for purchasing things from tampons to side winder missiles, you were crawling under a car. My code ran installs on agency systems I cannot mention. So, I must be the idiot in this thread.
I told you once, say something positive or stay out of my thread. Let it rest, go back to your garage, whatever. One more attempt to highjack my thread and my advice will have me setting the administrators on you. To put it lightly, you are out of my league. I could school you in one month on everything you think you know. Yes, that is not bragging, I am that smart.

Russell Ormerod

Such Arrogance! Anyway empty barrels make the most noise. Look that up! You do as you please with the admins I am here to help others. Clearly you know it all. Cheers mate. Let me go help others and not waste my time listening to how clever you are.

Ernest Jones

Go away. Do you have a mental defect? I trust a shop mechanic about as far as I could throw him.

Arrogance doesn't come close to describing me. Again, go do what you do. Let me have my peace. Honestly, and this for everybody reading this thread. Do you honestly think someone like me would ever broach this subject if it wasn't something I actually cared about?

Russell, 3rd and final warning.

daniel Allen

You are insignificant and arrogant

Kebowers47

Electrical (poor connections) have been and still are the major cause of 'not working' automobile features/components. When emission controls became mandates, GM performed a very good technical evaluation of what they needed to change to ensure the emission controls were reliable and durable. They found 'electrical connections' were The Problem. GM undertook the huge change endeavor with their DELCO division leading the way. They worked with the manufacturers of connectors to design high integrity waterproof connectors with gold plating on all contact surfaces. There had not been and significant improvements in electrical connectors in 30 years and WW-II technology was typical, That research and development program was 'Industry Changing' and DELCO freely licensed the patents to all. It tied in nicely with the needs of NASA.

A later development by 'Others' in Canada developed a liquid treatment that dramatically improved the integrity and Quality of CONNECTIONS, proven to dramatically improve even 'clean-room' quality fresh gold-to-gold connections. This invention is called STABILANT-22. All Military electronics techs and IBM equipment repair tech carries and uses it as do most every other electronics tech and high quality automotive electrical shop. It is a BIG SECRET in the electronics and auto electrical service businesses.

It CAN be ordered through MOST Auto Parts organizations. but most Counter Clerks know nothing about it. I personally attest to the ability of STABILANT-22 to cure bad connections. Scrape off the obvious corrosion, add a SMALL drop of S-22, make and seal the connection. No more come-backs for that connection-ever.

using S-22 on the MAF connection of the 4 InfinitiQ45's I have owned completely prevented ANY connection caused rough idle, etc so common to these cars. I use it on every electrical connection I make. A 10ml dropper bottle costs about $70, but that is a lifetime supply for anyone but active electrical/electronic techs.