what is this plugged into voltage reg

[merrill]

so, purchased a new voltage regulator from k n k.  when I pulled the old one out, there is another item plugged into the regulator.

it has a plug on one end for the voltage regulator, a small square box then a connection to the wiring harness.

does anyone know what this is?  there do not appear to be any markings on the box.

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[Tom230sl]

It is a Fuse Box, probably, and it was used for the original Radio wiring noise suppression. the Wire coming from the Harness should be Red/Green and the Wire from the Fuse Box going to the inside of the car was Black, this set up was wired to the Ignition Lock position I for Radio use without turning the Ignition on all the way. Early 230 SL did not have this set up.



Download Attachment: becker diag.jpg
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[merrill]

Tom,
I was doing some research and it appears the old voltage reg was externally requlated.  maybe that was what was plugged in line.

the new voltage reg appears to be internally regulated?

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[J. Huber]

Hey Matt. You may recall your discussion on Voltage Regulators led me to replace mine. The one I purchased from K & K seemed to plug in exactly as the old one. Three spades. It is slightly smaller in size than the original (but a lot shinier!). I have the auxillary fuse box right next door to the VR but not connected to it. By the way, that fuse box has a hot wire even when the car is off ! :|  Trust me...

PS just went and looked. It seems there are two boxes on mine. The fuse box and the a smaller box on the grill side of the VR. Is this the box you mean, Matt? It has three prongs and does seem to head into the VR.

James
63 230SL

[merrill]

Download Attachment: close up of suspect item.jpg
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Download Attachment: new volt reg.jpg
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Download Attachment: old and new reg.jpg
46.25 KB

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[merrill]

oops, in this post and the one below I have attached some photos for review.  I still do not konw If I need to use the suspect item with the new voltage regulator or not.


Download Attachment: old volt reg with item plugged in.jpg
37.97 KB

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[J. Huber]

Matt, you should have three wires that plug into this thing, originating from the main harness.

James
63 230SL

[al_lieffring]

I have never seen this extra box wired into the regulator circuit of any Benz that I have ever worked on.
This same voltage regulator was used on most european cars of the same era with Bosch electrical systems. So it could be for one of those non-MBZ applications.

My guess is that it is a balast resistor to change the voltage output of the alternator above (or below) the setting of the stock regulator.

I would leave it off.

The terms "internal or external regulator" refer to if the regulator is mounted directly on the alternator (internal) or on the fender well (external)

Al

66 230sl
113-042-10-014715
904/396 blue, Ivory Tex
condition: not-as-rusty-as-before-bucket

[J. Huber]

Al, you may be right. But I'd still like others with earlier 230SLs to look and see if they have this small box. So many times, it has initially looked my car was modified, only to discover it was an "early" thing.

and if it was "left off" would that mean the three prongs from main harness that go into it would instead go directly into Voltage Regulator? (thereby bypassing it?)

James
63 230SL

[JPMOSE]

If one wished to keep the original look of the larger case, can the contents of the new voltage regulator be transfered to the old case?  OR.....would this be opening a big can of worms?  :evil:

Best Regards,

J. P. Mose
1968 250SL
1987 560SL

[merrill]

so, i finally broke down and sent gernold an e-mail for help.  
below is his response

that Box is part of the Radio noise suppression system,
either use it as was or don't use it at all, it will depend on what Radio you are planning to use,


Hope this Helps and Good Luck with your SL,
Gernold


Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[al_lieffring]

quote:Originally posted by J. Huber

Al, you may be right. But I'd still like others with earlier 230SLs to look and see if they have this small box. So many times, it has initially looked my car was modified, only to discover it was an "early" thing.

and if it was "left off" would that mean the three prongs from main harness that go into it would instead go directly into Voltage Regulator? (thereby bypassing it?)

James
63 230SL

James

Try doing a charging system voltage test with the small box installed and then with the harness attached directly to the harness.

Try running the motor at 2000 rpm with a volt meter attached to the battery. With all the power consumers turned off it should read at about 13-13.5 volts. If there is no difference with the box connected I would see no reason it shouldn't be left attached in the circuit.
I would be interested to know if the voltage reads higher, lower or has no effect with the extra box attached.

Another possibility would be that the box is a noise filter for the radio instalation.

Al

66 230sl
113-042-10-014715
904/396 blue, Ivory Tex
condition: not-as-rusty-as-before-bucket

[J. Huber]

Hey Al,

I am about to try your test -- only have a hang-up... How do I know which wires go where. The VR states D+, DF, and D I believe (reads like my report card in High School!) The wires coming out off harness appear to be black, brownish (with a second bluish one), & a reddish one? which wire would go where?

James
63 230SL

[al_lieffring]

quote:Originally posted by J. Huber

Hey Al,

I am about to try your test -- only have a hang-up... How do I know which wires go where. The VR states D+, DF, and D I believe (reads like my report card in High School!) The wires coming out off harness appear to be black, brownish (with a second bluish one), & a reddish one? which wire would go where?

James
63 230SL

D+    solid blue and red w/ blue stripe
D-    Brown
DF    Black



here is a pic of the back of my regulator connector

Al

66 230sl
113-042-10-014715
904/396 blue, Ivory Tex
condition: not-as-rusty-as-before-bucket

[J. Huber]

Got it!...Thanks Al. I just tested things.

The numbers with it and without are almost identical. A smidge less at idle (both battery and ballast resistor) when the bugger is not in the equation. So I think I'll leave it off. Last question -- I bet you and Gernold are correct that it is a radio suppressor thing -- will this now effect my radio with it out? It's not the original radio (although it is a Becker Europa II).

James
63 230SL

[al_lieffring]

quote:Originally posted by J. Huber

Got it!...Thanks Al. I just tested things.

The numbers with it and without are almost identical. A smidge less at idle (both battery and ballast resistor) when the bugger is not in the equation. So I think I'll leave it off. Last question -- I bet you and Gernold are correct that it is a radio suppressor thing -- will this now effect my radio with it out? It's not the original radio (although it is a Becker Europa II).

James
63 230SL

There was a Becker radio I think it was a Grand Prix series that had 5 bands and the extra filter was for one of those frequencys, not the AM (K) or FM (U)

Al





66 230sl
113-042-10-014715
904/396 blue, Ivory Tex
condition: not-as-rusty-as-before-bucket

[JPMOSE]

If one wished to keep the original look of the larger case, can the contents of the new voltage regulator be transfered to the old case? OR.....would this be opening a big can of worms?


Best Regards,

J. P. Mose
1968 250SL
1987 560SL