Multiple electronic issues
 

For my 91 300e W124:

1) Previous owner took the strip fuse for the fan/blower out. When I put one in, the fan blows full blast on one speed, either off or on. No low, med, hi.

2) Light for the transmission dash is out. Cannot tell at night what gear you have.

3) Drivers side seat sometime goes crazy. Usually happens after I reconnect the battery, the seat will jump around, even though the seat adjustment button
is not touched.

4) Check engine light is on. The pulses indicate numbers 16 and 17.

16 - EGR switchover valve - should I just replace?

17 - I already changed the oxygen sensor about a year ago, as well as the OPV (fuse is good).


Are these issues all related? Where do I start?:confused::confused::confused:

#1 My guess would be the blower motor regulator is shot. It is in the engine firewall area and not easy to get at.
#2 You will have to pull the strip and replace the bulb. Not sure how to do it on your car but BE CAREFUL as it will probably break.
#3 probably has dirty contacts somewhere in the seat area. The car is 25 years old.
#4 There are charts that give you the code messages. I don't have them.
Track down Jim Forgiones website. He has instructions for building a simple code reader. Sounds like you need one. And maybe a subscription to AllData for your car.
Anziani
'97 CL600 55K

AutoZone and some of the other chain after-market parts stores will read and clear the codes without charge when the check engine light comes on. You should go to see them.

The check engine light came on when the second of two glow plugs on my '98 e300td went bad. The light stayed after I installed new glow plugs. I went to the AutoZone store near me and they cleared the codes without charge. The light has not come on since then. The guy was gracious and didn't act like he was doing me a big favor.

I doubt they can do a pre-OBDII car. They can be cleared with the push button next to the LED (if there is one, not all of them had it) or with a Mercedes OBDI reader.

The first thing I would do (now) is check and clean each of the earth points

Can easily postpone the blower issue to a later time.

Transmission light: this is doable - if it is only a bulb replacement.

Seat: dirty contacts in the door area where the adjustment switch is or in under the seat?

Stretch: will double check ground points.

Update:
Replaced transmission light bulb with an LED one.
Cleaned EGR valve, replaced vacuum hose from idle control valve to intake hose.

Removed the original distributor cap and found yellow flakes everywhere.
Flakes were even in the boot part that connects to the distributor plugs.

Any clues as to what, why?

Rodents?

(What's the rotor look like?)

Time to replace the distributor cap, rotor, spark plugs and likely the ignition wires too. Apparently the engine, and the entire vehicle, has not been well maintained.

Rotor looked intact, just a little carbon on the tip.
Cleaned the contact points and rotor to see if any difference - negative.

Well (as mentioned above) replace the cap and rotor and measure the resistances of each of the leads.

If you've already cleaned the earth points - check for the error codes again (after a short drive).

Update: Replaced the rotor and cap, runs better.
Determined the yellow flakes were from the sly-glyde that had dried since installation about 9 years ago.