$240 voltage regulator

[jeffc280sl]

During a return trip from North Carolina to Maryland in 87F heat on interstate 95 my car hesitated briefly and died.  I was able to get off the road okay, traffic was horrendous with a 40 mile stop and go backup.  I turned the key and nothing happened.  Opened the hood to find a triple hole battery cell cover had popped off the battery which was smoking and very hot.  I had cooked the battery dry.    Thanks to the nav system I was able to find the closest towing service and 30 minutes later I was in a good old boy garage in rural Virginia.  Decided I needed a new battery and one was ordered by the garage owner.  With the new battery installed the car started fine.  The owner put an ancient battery tester on my car and found the alternator was putting out in excess of 16 volts.  Voltage would peak his tester and then an overload protector reset it to zero.  This happened continuously.  It was decided I needed a voltage regulator.  The owner called a friend down the street that repairs alternators and starters who said he could take a look at it.  I have a 2 year old 55amp Bosch alternator with an internal voltage regulator.  Many thanks to Butch the owner and tow truck driver and down the road I went.  The tech removed the failed regulator and installed a new one while my car was in his parking lot.  Took about 15 minutes and after that my alternator was repaired and 14.25 volts was measured at my new battery.  Both service guys were fantastic to deal with and their service was great.

So within 2 hours of getting stuck on interstate 95 I was back on the road.  That's how a $35 regulator ended up costing me so much.   I thought the failure mode would be a complete charging failure.   In my case the failure mode was unregulated voltage which cooked my battery.

[bpossel]

Jeff,

Sorry to hear you had trouble, but sounds like you were very lucky to find the guys you did.  You could have been stuck for a lot longer and spent the night in a motel, having to get up and check on the car every hour.....
Bob

[jeffc280sl]

Hey Bob,

You're right.  I was very fortunate that things worked out the way they did.

[awolff280sl]

Jeff, you got lucky. Do you figure that the dry battery caused the regulator to fail?
Is your alternator mounted up high? I ask because my 55amp is mounted down under and I decided to go externally regulated. But I did make a type of harness that on one end plugs into the existing connector, and the other end plugs into an internally regulated 55amp, just in case.

[jeffc280sl]

Andy,

I was lucky.  I just read that an overcharged battery will boil the sulfuric acid and distilled water mix. The casing of the battery can become hot to the touch, and begin to melt or swell. Flammable hydrogen can build up inside the sealed cells of the battery, causing swelling of the casing under pressure and seepage through small vents.  This sounds like my condition.  I'm at a loss to explain how the water levels otherwise became so low.. The pressure popped the lid over the battery cells which helped to vent the gas.  I suppose in an extreme situation there could have been an explosion of some sort.  There was no indication of an over charge condition on the instrument panel.  I think it only lights if a low voltage situation occurs.  Would have been nice if it lit up in an over charge condition as well.

My alternator is mounted in the high position and has the internal regulator.  Am I to understand that you have redundant voltage regulators in operation on your car? 

[graphic66]

Make sure to really clean up the area of the battery. You probably have acid residue everywhere. I would wash the area with hot soapy water followed by a rinsing with baking soda and water to neutralize the acid and then rinse the whole area with water. If not you could find some peeling paint and corrosion in a few weeks. Make sure to get under the battery tray, you may want to take the battery out. I would wash everything under the hood myself as the acid could be dispersed under there pretty good.
  It would be nice to have a voltage gauge in these cars, that would show overcharging, but it is a very rare problem, much more probable is undercharging.

[jeffc280sl]

graphic66,

Good suggestions, thank you.

[awolff280sl]

Jeff, no redundancy, just a 55amp externally regulated alternator. The harness (not presently in the car) was made in case I eventually change to an internal regulator.

[jeffc280sl]

Andy,

Understood. 

Seems the battery/voltage regulator took out some other electrical items.  All of the right side blinker lamps are blown.  Front, back and dash indicator.  Replaced bulbs except the dash indicator and all is working except that light.  I hate the idea of taking the dash apart again.  My stereo or preamp is also not working.  No blown fuses. 

[awolff280sl]

Sh--t. You mentioned that you were getting 16 volts at one point. If you end up replacing the dash lights, consider LEDs. Also, you may want to consider a gel battery.

[jeffc280sl]

I'm glad that no wiring was damaged.  Thanks for your suggestions.

[ja17]

Hello,

Some other thoughts................  I once was sent to NYC to drive a 230SL back to Columbus Ohio.  When I got to the car, I replaced the starter and got it running fine. However the alternator was bad and was putting out no current at all. It was
Sunday morning by now so I simply drove to a discount store and bought a cheap $50.00 battery. I had both batteries charged and began to head west. At about 100 miles, the first battery would run down low enough that the engine would begin to miss. I then would pull off the interstate and switch batteries and begin looking for a place to have both batteries quick charged. I would grab a bite to eat while both the batteries were quick charging. I repeated this cycle 5 times and made it the 500 miles to Columbus. Total cost was the battery and five chargess  ($150.00 total). However I did have the charging problem to fix once we got home. This is an option to consider in the event you do not find some great help as jeff did. Needless to say, no unnecessary radio, lights, wipers, blower fan, etc. during the journey. I did run into some rain during the journey, and used Rain-X on the windshield to avoid using the wipers.

[Wes Bender]

That works well, Joe.  Even better is if two cars are traveling together.  You can stop occasionally and switch batteries.  Of course, the batteries have to be similar in size.  I have a friend who rode a Harley 700 miles with a set of jumper cables attaching his machine to his buddy's bike, but that's a story for a different time....

Cheers,

[Benz Dr.]

I see a slightly different moral to this story. Everyone is talking about the repair but little was said about the place that fixed it, which is normal for around here

 If you broke down along some busy highway deep into a large city, you might of seen it fixed as quickly, or maybe not. Some of those places are so busy they can't look at you until the next day. These '' Good ole boys '' knew what to do and how to fix it. I bet they would have even taken the alternator to a place to get it fixed ( it they didn't have the parts ) just so you wouldn't be stranded. In the city, you'd be expected to find a place to stay and take care of it yourself. These guys would of put you up in the barn at least. 

 The next time someone around here throws a wrench at some undeserving mechanic, :'( I'll pull this story up to remind them to be a bit more apreaciative. 

 

[Mike Hughes]

That is exactly what was going through my mind when I read the original post:  How lucky he was to have broken down near a full service gas station with a couple of experienced guys on duty who weren't afraid to touch a 40+ year old "furrin" car, knew how to diagnose the problem, how to fix the problem, where to find the appropriate parts, and send a stranded motorist on his way at a fairly reasonable cost in a matter of a couple of hours.

[Benz Dr.]

Yeah, especially when they could of skinned him alive and hung him out back of the barn to dry in the sun......
  Kind of guys that make the notion southern hospitality more than mere words.

[J. Huber]

This reminds me of an incident that remains a mystery to this day... About 15 years ago, I had driven my car from southern California to South Lake Tahoe (about 500 miles) and was enjoying life -- when suddenly I heard some really loud chattering or clicking from the engine as it revved. It was clearly something inside the valve cover. It was really loud. Anyway, luckily I was able to find a small independent auto shop still open and the guy must have heard me coming. So he and a buddy pulled the valve cover off. He said I had a loose something or another (truly I have no clue). He said we can either wait and order the part OR he can try and mend it by "gnurling" the threads or some verb like that -- said it might hold. I was so naive to this stuff I said ok go for it. So he did something and put it all back together. Sound was gone. Car ran as usual. Charged me 100 bucks. Fast forward to last time I had valves adjusted: my trusted mechanic said everything looks normal in there. Engine has continued to be strong and reliable... The Mystery continues.

[Benz Dr.]

Thyat would have been the ball stud adjuster. He probably peened the threads a little bit so they would hold. Looks like it worked too.

[J. Huber]

Nice call Dan. I just located the work-order. He called the issue "valve lash..." "found #3 exhaust adjuster to be loose...adjusted all other valves to proper specs -- removed #3 adjuster and reworked threads to firm up..." Sound about right? Yes it surely did work -- that was at 82511 (1993) -- I am at 22000 now. Thanks.