1968 W115 220 Gas Starter will not activate
 

Hi - The starter on my 1968 Mercedes 220 Gas 4 speed . Stopped activation .
The car will not turn over . I took the starter to Napa but the person did not know hiw to use the tester and blew a fuse in the building !!!! So I bought a new one . This did not solve the problem . Went back to Napa and another person fixed the test machine . And my old starter worked !!! Hahha . So I have about 10 Volts and am charging the battery . Have not got the battery up to 12 V .
My first thought was the ignition switch . As wires from the switch go to the starter . 7 Bolts to remove the starter (Again) . Does anyone know how to jump the starter ? Is it a jumper from the Bat + to the small screw on the starter ? I wouldn't think it would be difficult . I have 4 batteries !!!!! I don't think they can all be bad !!! hahah . Any help ?

If you have 10V the battery will never start the car. 10V = DEAD BATTERY. Simply turning the key is enough to make it go completely flat without ever even bumping the solenoid.

Get a new battery and try again.

It is critical to understand that 10V does not always = bad battery and to determine if there is a charging system problem.

Recharge the battery then have it load tested or try to start the car. With a fully charged battery, engine running, you should see 13.2 - 14.2 ish. The voltage will be a bit low as the alternator recharges the battery, if you see anything over 15 V, don't run the car as the high voltage will damage the electrical system.

If the battery has not been charged / loaded in the past 8 hr, a fully discharged battery is anything below 11.70 V, a fully charged battery is 12.66 V

If the battery is fully discharged but still good, the starter won't operate or will just click because the fully loaded voltage will drop even farther.

If there is a shorted cell ( failed battery ) and the battery is fully charged, the voltage will drop to 10.55 ( Lead acid batteries at full charge are 2.11 volt per cell. ). This will still crank the engine but it will be slow.

Go back to NAPA with all 4 batteries.

Leave if the first person you dealt with earlier is not at lunch. Assuming he is...

Have all 4 batteries LOAD tested.

I've seen batteries with normal voltage readings (12.6 or >) flunk a load test.

Battery
 

I charged the battery . Went to Autozone . The battery is fine . I guess I meant amp load . A low battery can turn a starter . Too low , it will not . My battery is fully charged .

Battery
 

Yes I sure did . The battery passed load and is 12 V . I think Napa can have their starter back . I went back today and re-bought my core . I had a Fiat with the same problem . I suspect the ignition switch . Anyways I compression started the car and it runs great once going ! :)

Does anyone know how to remove a W115 Ignition switch . I pulled the contact plug off the back & hit it with DE-OXIT . No luck . Thanks

Battery
 

Yes thanks . I've dealt with generator output with my 6 Volt Vw . I did not know about the load part though .

Compression is the only way to start the car now . Solenoid has a light click with the key turned .

We checked the battery at Autozone and it is fine in both categories . Same thing as a horrible Fiat X1-9 . Intermittent, of turning the key and nothing .....
I removed the plastic contact clips on the Fiat ignition to out harness . Hard soldered the wires together and the problem was fortunately solved .
The Mercedes was gradual . Occasional no start . First thing I thought of was the battery . The problem came back . Then came back as in not activating the solenoid . Although I do get a light click .

It was an interesting day . I called a few mechanics and they wouldn't touch it . They knew what I was explaining . The ones who may take it . The car could sit there for months and months .

Once I can start it I will check the alternator as you say . I did find a slightly loose ground strap to the alt .

I wire brushed all grounds and sprayed on DE-OXIT in the contact areas .

Going to the starter is the + Battery and the ignition . And then proper ground of the starter and engine . And to the Chassis . That's where I'm at . :)

Seems to me - regardless of how it's started, the ignition switch needs to be in attendance.
If an ignition switch bows out while the car is moving down the road, it will quit running.

Ignition
 

Hmm could be . Perhaps there's still a bad wire . Maybe the tripper wire for the Solenoid . I have the Volt meter working now . The trip wire should be at 12V
with the switch on . Anyways it's nice to rule out most other problems . It will be interesting

Jumped it
 

I jumped the starter and have been driving it . Runs fine for now . I'm waiting on a ignition switch . Hopefully that will fix it