'68 280se voltage regulator, UNOBTANIUM? Repairable?

[RingKingPin]

Hey Guys,

I've been really enjoying my 68 se that I picked up a little over a year ago. She's been nothing but a pleasure to drive and after doing all sorts of mechanical fixes, she's been absolutely flawless, until recently.
My GEN light was coming on so I checked the voltage while running at the battery and it was at 16 volts! Then it jumped to 13.25 and I parked her. A couple of days later, I started her up. Before starting her, the battery was at 12.8v, once I started her up, she dropped down to 12.5v. So, I am assuming the regulator has taken a dump.
I'm surfed the net, looking for an exact replacement but I don't see anything that is identical to what I have:



here is what all the stores are saying I should get: http://www.koperformance.com/part-number/0021547406/BOSCH

this is what it looks like:


as you can see, it's not identical, no plug on top, flanges are different etc. Any suggestions? Can I open and rebuild what I have?

I'm stumped , thanks for your help, I'm all ears!

[jgranzier]

I believe a have a similar one - off a 68 280se

I ll send you a picture

[D&W]

my mechanic installed a replacement voltage regulator in my '68 280se the other day... so they must be out there. i can take a photo if you like

[JMela]

Don't think the old ones serviceable, they seem to be potted in wax or resin or something; Bosch likely just produces the single available version. Replaced mine but it was a vertically-mounted unit just like the new version you have pictured.

Plug is in the base although mine was mounted on the RS fender rather than the left by the coil. Idiosyncrasies between models, I guess.

[bwostosh]

I've never seen a side plug mounted near the coil, there are solid-state replacements bolt-it plug-in at the local normal parts store, VW, BMW motorcycles, they all used the same Bosch unit, bottom plug either green of yellow tape about the bottom of the case. Get them from the pick-a-parts yards used.

[RingKingPin]

My car is a little odd, it is an early run of the 280se. VIN# 108.018 12-002876.

It seems like I've run in to multiple problems with parts that are mismatched, cobbled together, etc. Another fine example is this regulator. I called the people at SunValley and tried to describe it as best I could. The man said "oh with the colored tape around the bottom and the plug on the bottom?" I explained mine has no colored tape and the plug is on the top. The man figured he knew what I have and sent out the wrong item. They think they have one in stock but haven't heard back from them.
There are some resistors, some caps and some contacts on this thing but I can't imagine what would go bad, maybe a cap dried up or a contact is too worn?

Mine is on the left. No plug and play replacement and I don't have a schematic... best bet for me is to find another one of these things,

[RingKingPin]

Originally Posted by bwostosh

I've never seen a side plug mounted near the coil, there are solid-state replacements bolt-it plug-in at the local normal parts store, VW, BMW motorcycles, they all used the same Bosch unit, bottom plug either green of yellow tape about the bottom of the case. Get them from the pick-a-parts yards used.

Now you've seen it!

[RingKingPin]

It kind of looks repairable but not sure where to start...
I'm guessing one of the contact points has worn away over time and fell out of tolerance? I suppose I could try replacing that but it's staked and I wouldn't know where to get another identical contact.



I'll sit here on my hands waiting for Sun Valley to call...

[RingKingPin]

Originally Posted by jgranzier

I believe a have a similar one - off a 68 280se

I ll send you a picture

Do you have an extra one?

[JMela]

MB Classic Center might have a better answer for you - I'd give them a call.

[801mbz]

I have one of those but I think it is not the voltage regulator. The voltage regulator is on rh inner fender.

[jgranzier]

i have one
send me your email

[RingKingPin]

Originally Posted by 801mbz

I have one of those but I think it is not the voltage regulator. The voltage regulator is on rh inner fender.

You have a flux capacitor too?

[RingKingPin]

OK, so I got my "new" flux capacitor (regulator) from Sun Valley. It came in a little dirty so I sanitized it a bit, wired it up and she was charging 13.10 at idle! Hooray!
Then I whacked the throttle and the voltage jumped up, no biggie, that's normal. Revved it up a little higher and it jumped up more... all the way to 17v! What the heck? I KNOW that's not normal... any ideas? Is this normal? I've NEVER heard of a 12v system charging over 15v but then again, I'm a neophyte when it comes to this car. Is it possible that I got another regulator that is messed up? Any ideas would be appreciated.

TIA...
---RKP

So I went back down to the garage, put the heaviest load I could on it, turned on the brights, the stereo, hazards, etc. and everything seemed cool, was charging at the proper voltage then it just fell on it's face.

I guess there must be a problem with a shunt in the alternator which is making it send out wayyyy more voltage to the regulator and burning them up. Oh joy... Now I need to swap out the alt. and find another regulator.

A friend of mine thinks that regulator was used on old VW cars as well as some cessna planes...

[RingKingPin]

Well, thanks to Egranz, I'm going to get to play with my SECOND old school regulator. This time I'm going to add a safety ground, check the other grounds and replace the alternator. Heck, I've burned up two, have one on the way, I gotta be careful, there can't be too many more of these left! I'm trying to keep everything original on the car.