Spartan191

I have spent the better part of today looking through pages of information here, all helpful in different ways, but none of it seems to be the same as my experience. Then again most MBs seem to be unique in their failings at the best of it. I did find one contradictory piece that has me totally screwed up now. One article I read the person helping said to connect the +ve first, then the -ve and disconnect them -ve first then the +ve. That is the way I have always done this, yet in a different post, another helpful member says if you disconnect this way it will cause the potential burnout of the front SAM unit...WTF, talk about confuse a guy... Anyway on to my electrical drama as it occurred, excuse my story writing style. It is just easier to relate the experience as it played out.

I have been a member for about a year. I have read so much and found very helpful information from so many people. A lot of it has given me a preventative program instead of a reactive one.
However, I was greeted Monday morning with a bit of a strange electrical issue. Now, most of the ones I read and have now specifically searched for...have one thing in common with my issue. Their engine will not run or shuts down very quickly. This is not the case with my problem!
On the morning stated, I started the car as per normal and I heard an extraordinary fan roaring at full speed (in the engine compartment) drowning out the sound of the motor itself. A bit strange I thought and I tried to turn off the A/C, thinking it must be on. No response from the controls in the centre, as I looked to the instrument cluster it just blinked out and the needles all set to zero. Frustrated, with my wife standing at the side of the car, I went to operate the window, nothing worked.
I had an appointment to go to and this meant uncovering the other car and getting that out...Bugger...I opened the door and told her and then for some stupid reason I only moved the car out of the carport and switched it off. We went and got the other car ready and I realised I had to move the C180 again, so I get in, start-up and now everything is working. I wait for 5 minutes, still no problems, so we put it down to the extremely cold weather that morning and I tell her I will go. I drive for an hour and a quarter in country and city traffic without an issue. Speeds vary from 50km/h to 100km/h, not a fault indicated on the computer screen. I make my appointment and ninety minutes later I am ready to go, start the car, fan roars, but everything is working, so I head out into the traffic, about 3 km down the road the instruments go out, so I indicate to pull over, no indicators. Fortunately no traffic either. I decide to try both side indicators...nothing, wipers...nothing, hazards OK, headlights and tail lights OK, brake lights OK, Radio OK...so I turn off the motor. I wait for ten minutes and turn to the ignition position all is working I can just hear the hum of the fuel pump. Try the indicators all work, start the car and the fan roars, and nothing works. Switch off, take the key out again.
Plan a trip home with minimal corners, wait for a break in the traffic and then go, essentially in a straight line except for one rh turn, again lucky, no traffic around. I decide to pull over and let the wife know why I am so late. I shut down the car and I phone her, explain it is still having problems and I am about to enter the major roads, one being an expressway. So far I have travelled 80 km. After I hang up I decide to put the indicators on first before starting so for at least a few seconds there is some warning and I start the car, I drive off and not noticing straight away, everything is working again. Once I am on the expressway I then noticed that all was good, I have instruments working and windows as well, so I set the cruise and headed for home.
Due to our ever changeable fuel pricing, it was .99c a litre so I filled the tank because I had seen some other places where they had put the price up to $1.59 a litre, again I had to turn off for this and again I lost all the gauges, but I was only 9km from home and I could travel the back road without worrying about any traffic, so all the way home without instruments, indicators or windows.
Since being home the car has not started once without losing the instruments, indicators and pwr windows as well as having that fan running at full power. The car starts fine, the Battery voltage is at 12.6, I have no idea where to even look. there are no malfunctions registering when you turn on.
Things I do remember, I did drop the key one-day last week. We did get the EPS warning again, but it self cleared and left no malfunctions on the next start. It does have an aftermarket Dble din satnav radio and reverse camera with a regulator to compensate for the hook into the reverse light feed. The EPS I think might be caused by tyre wear and balance, as it is coming due for new ones. So, apart from RHD, everything is the same as a C180/200K LHD.
I could really use some knowledgeable C Class input on this one. I did a search and the closest I got was E320 by the bucket loads with similar issues but different features and I am not even sure if the electrics are the same.
Cheers Jeff