Help Mercedes W108 250s 1966 Alternator

[Solmeero]

Hi guys - I bought a 1966 Mercedes 250s column shift manual yesterday.
After driving it home for 5 hours it broke down 1 mile away from my house.

The roadside recovery guy came and did a quick check and he believes it's the alternator.

Does anyone know if there is an alternative alternator to use? The car is standard no mods and has been restored to its original spec.

Any advice would be appreciated!

Thanks in advance
Sol

[CTD]

That car should take the standard BOSCH 35 amp alternator. At least the fintails did! Did you test your charging system at all?

[Tony H]

wow-my first Mercedes was a 250S with a column shift 4 speed. I had found the parts to convert it to floor shift but someone T-boned me before I did the conversion.

[Solmeero]

Originally Posted by CTD

That car should take the standard BOSCH 35 amp alternator. At least the fintails did! Did you test your charging system at all?

Yes I checked today and it has the standard 35 amp Bosch. I will be handing it over to my mechanic and he will run additional checks.

I'm just wondering if there is an alternative to use? Something with more power that is compatible? I saw another post whereby someone upgraded it to a 55amp?

The current amp wasn't sending enough power to the battery and it caused the car to just turn off while driving...I did however drive it for 5 hours with lights and heating on after buying it. In addition the previous owner hadn't secured the battery in and cables were loose - which prob played a role too.

[Solmeero]

Originally Posted by Tony H

wow-my first Mercedes was a 250S with a column shift 4 speed. I had found the parts to convert it to floor shift but someone T-boned me before I did the conversion.

Yes this is exactly that...I'll upload some pics of it when I get to my laptop...the column shift does take some getting used to...this also happens to be the first merc I've ever bought.

I wonder if I can find someone to convert it for me?

[97 SL320]

US domestic cars / light trucks came with three speed manual on the column from 50's to 70's . The "Three on a tree" was common. Four speed was typically on the floor.

[CTD]

Originally Posted by Solmeero

Yes I checked today and it has the standard 35 amp Bosch. I will be handing it over to my mechanic and he will run additional checks.

I'm just wondering if there is an alternative to use? Something with more power that is compatible? I saw another post whereby someone upgraded it to a 55amp?

The current amp wasn't sending enough power to the battery and it caused the car to just turn off while driving...I did however drive it for 5 hours with lights and heating on after buying it. In addition the previous owner hadn't secured the battery in and cables were loose - which prob played a role too.

The 35 amp Bosch alternators will do the job just fine, provided they are functional. Another thing to check is the voltage regulator. If either the regulator or alternator is bad, I would recommend rebuilding or replacing both.

[Benz Dr.]

Originally Posted by Solmeero

Yes this is exactly that...I'll upload some pics of it when I get to my laptop...the column shift does take some getting used to...this also happens to be the first merc I've ever bought.

I wonder if I can find someone to convert it for me?

Not that hard to do. You would need the shifter parts and could use your trans with a top loading shifter box.

[Solmeero]

Originally Posted by Tony H

wow-my first Mercedes was a 250S with a column shift 4 speed. I had found the parts to convert it to floor shift but someone T-boned me before I did the conversion.

Here are some of the pics...

[Idle]

I think the loose battery cable is the problem.

For those of you wondering how this electrical thing works....

The battery provides power to start the car. That's it's only function.

The alternator then takes over and provides electrical power to everything. There is also enough juice left over to charge the battery back to starting power levels.

But if the cables are loose the power produced is only intermittent. Then the battery comes back into use as the electrical system pulls power from the only source remaining: The battery.

So if the alternator is not charging, or if it is charging and the power is not being distributed due to a cable not making a tight connection, the battery will slowly drain to about 7.2 volts and then everything quits because that is the bare minimum needed to keep the ignition system going.

So by all means test the alternator for output. If it checks good tighten the battery cables, clean the negative connection where it connects to the car, replace the engine grounding strap and do an on car test of the electrical system. Most auto parts shops are equipped to do such a test in their parking lot.

And don't forget: This is a 1966 electrical system we are discussing. So all of my advice here is period correct. Starting about 1974 everything started to change.

[FreddMersaid]

And if the battery it self is bad, the Alt will not be able to keep up, therefore you could kill the alternator.

Also, Is that white dash factory or is it just a pimped ride you purchased ?

[Idle]

Originally Posted by FreddMersaid

And if the battery it self is bad, the Alt will not be able to keep up, therefore you could kill the alternator.

Also, Is that white dash factory or is it just a pimped ride you purchased ?

Yup, and the weirdest part of that is the battery might still start the car!

Been there, done that. This electrical stuff can get strange quickly.

There was a time when I had to take the car to an electrical repair shop to get the system read. At a cost of $5.

Now you can drop by any AutoZone and get it done for free.

[Mark DiSilvestro]

Repair/tighten battery cables, and make sure the battery is charged BEFORE testing.
You can upgrade to a 45 or 55 amp alternator if needed, including one of those with the integral regulator. The integral-regulator version just won't have the 3-wire connection for the external regulator wiring.

Happy Motoring, Mark

[FreddMersaid]

Is that white dash and panels factory or a "Pimp my ride" custom ?

[FreddMersaid]

"Now you can drop by any AutoZone and get it done for free."

Be careful what you believe from the auto part "technicians". Their job is to sell.
And, Dura Last Alternators and Battery's will not be the "Last" you ever buy.
They sucker many in with the "lifetime warranties" but how many do you want to change in a life time ?