Voltage Regulator Specs?

[hands_aus]

I had the charging system checked on Sunday by the local car club.

The guy said the amps output was down and it was likely the Voltage regualtor or the alternator.
I ruled the alt out because I had it rebuilt about 12 months ago.

Today I put a voltmeter on the battery terminals with nothing except the clock turned on.
at idle, 12.47 Volts
1200rpm 14.4 volts
1300rpm 13.5 volts

with lights (low beam) on
at idle, ~12.9V
increase the rpm, no +ve change The volts kept dropping... was 12.1 Volts when I turned them off.

So my question....

Should the battery terminal voltage increase or stay the same when the lights are switched on?

I cleaned the terminals with fine sand paper but with no difference.

Do I need a new regulator?

As always thanks for your help and any advice gladly received.



Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[bpossel]

Hi Bob,

You may already have these specs, but if not....  see attached.

I'll let another expert jump in here, but for what it's worth, I tested my voltage yesterday and at idle it was reading ~13.5.

I am running with a 35amp alternator, which is only ~2 years old.  I replaced my old one which was a 35amp unit not knowing that in my later model, I should have been running a 55amp unit.

Good Luck!
Bob

Download Attachment: 1.jpg
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bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[hands_aus]

Thanks Bob,
My big worry is about the voltage dropping away with the engine running and the lights on.

I have decided that the regulator needs replacing.

I went to the local Repco store and they say they have sourced a correct replacement from the original numbers taken off the existing unit and will call me tomorrow when it is available.

As the car club meeting is tomorrow night I hope they have truely found a correct unit.

In my travels today I saw a Bosch replacement regulator which was smaller and set in a molded aluminium case. The mounting holes were the same spacing but that is the only similarity and will be a last resort option.

I was wondering how difficult it would be to install an alternator 'internal' regulator in the existing external regulator housing?
I figure it would still work ok, just might need more venting.

This might become my next project.

For appearences I actually want to re-use the old case.

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Naj ✝︎]

Bob,
 

quote:In my travels today I saw a Bosch replacement regulator which was smaller and set in a molded aluminium case. The mounting holes were the same spacing but that is the only similarity and will be a last resort option.

The original points type regulator has now been superceded by the shorter electronic version (0 192 062 007), unless you can find a NOS.
I believe somebody on the site has changed the cover to the old one, or maybe the old cover simply fits over the new one...

naj

68 280SL

[hands_aus]

quote:Originally posted by naj

The original points type regulator has now been superceded by the shorter electronic version (0 192 062 007), unless you can find a NOS.
[/quote]

Hey Naj,

Does the new version have a model number like KE 57 ?

One auto electrican said it was a replacement.

thanks

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Naj ✝︎]

Bob,
 

quote:Hey Naj,

Does the new version have a model number like KE 57 ?

One auto electrican said it was a replacement.

KE 57 could be a local Ozzie designation. Could not find it in a Euro book  :oops:

naj

68 280SL