Where do I begin! I LOVE my '94 Mercedes S320. I’m getting over 23 mpg and I feel safe - it’s like driving a tank. It just hit 200,000 miles but now the bad news: gas light has been on for 3 years, now the SRS light is on; heat is on even though all the knobs and buttons and settings are off; I usually have to turn the key as far to the right as it will go (but not turn it on) and then open the hood - lift up fuse #15 and then put it back, close the hood and start up the car to get the heat on or off - depending on the situation - forget air conditioning! It isn’t working! I know this all sounds crazy and yes it is! Someone once mentioned two types of CODES. My wonderful mechanic is frustrated. I am frustrated. I really don’t want to get rid of this car yet, but what can I do? It sounds to me (a mere layman!) like a wiring issue or??? Any thoughts on this? Thanks so much!
If I were in your shoes I would get a second opinion for a qualified mechanic, someone who understnds Mercedes electronics. You could also get an estimate from the Mercedes dealer, and that would likely amount to the price of a new economy car.
The estimate from an independent and capable mechanic will allow you to make a decision With the air gone and the other things, I would get rid of the car. A 16 year old high end Mercedes with 200,000 miles on it is a future money pit, and unless you are well heeled, you may not be able to afford to keep it running well into the future.
However, that decision is yours to make; many people we hear from that inherit such a vehicle can’t wait to get rid of it when the bills start coming in.
You’ve probably had good use out of it, but like a friend of mine overseas who had an identical car, once engine or transmission problems start, it’s game over.
The 1994 model year had two major issues; a degrading wiring harness and an climate control evaporator that leaks.
It sounds like you have the symptoms of both.
The degrading wiring harness causes all sorts of electrical gremlins, and chasing down various faults without first replacing the harness is counterproductive.
The leaky evaporator is a somewhat pricey fix, but once down the climate control will be fine for a long time.
The SRS light usually come on when the connection ring in the steering wheel becomes sticky. This is not an expensive repair.
Your mechanic should of known of all these issues if he’s familiar with Mercedes. If he’s not familiar, it’s time to find a mechanic who is well versed. The 140 chassis Mercedes is a complicated vehicle and it takes a competent tech to work on them.
So you have some rather major repair bills in front of you. You need to decide if you want to keep this car for another 150k miles to justify these costs, or unload it and move on to a newer model. However, anyone who knows these cars will want proof that the known issues of wiring harness and evap have been fixed before purchase.