Author Topic: Coil / Resistor wiring plus Bosch gizmo near coil  (Read 1386 times)

230S-111.010

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Coil / Resistor wiring plus Bosch gizmo near coil
« on: August 30, 2024, 15:28:56 »
Question is on a 1966 230S - but wondering if may be same as a 230SL or 250SL.

I'm trying to figure out the wiring for coil/resistor and particularly the little Bosch gizmo mounted just above and forward of the coil - ORANGE arrow in attached picture. Car was NOT ordered with a radio so it's not for radio suppression (father bought car new). Tried to get the Bosch part number off of it - can't make it out. Something like "0 3?? ??8 001".

I had Pertronix setup - which failed and need to get the car running ASAP so back to the points distributor.

I had previously removed the resistor which are needed with points. The coil I'm using is the 1.8K Bosch coil and the matching resistor.

I don't recall what that little Bosch gizmo (orange arrow) gets wired to. It has the bakelite 4 prong square connector w/ 2 black wires (1 is thicker), 1 brown, and 1 black/red wire.

The thick black wire (PINK circle) and the black/red wire (BLUE circle) exit the harness near the coil (GREEN circle) along w/ the brown which goes to ground. Guessing these two wires should go to the coil or resistor - just not sure how to arrange.

I have the "Passenger Cars starting August 1959" service manual but it unfortunately does NOT have 230S wiring diagram. 220SB looks to be the closest and this gizmo doesn't appear to be there. Wondering if I need a later service manual or similar to maybe 108/250S or early 113 wiring diagram (which I don't have). The 220SB diagram I have has the resistor in series w/ the red/black wire - with no other wires to coil or resistor. These two wires from the Bosch gizmo must go somewhere.

Thanks!
1966 230S
1998 C43 AMG w/ 5.4, Wavetrac LST, 6 MT
1959 190SL - sold

rwmastel

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Re: Coil / Resistor wiring plus Bosch gizmo near coil
« Reply #1 on: August 31, 2024, 03:22:07 »
Is the car French?  I believe they had some interesting roll over safety device that killed the fuel or ignition.
Rodd

Did you search the forum before asking?
2017 C43 AMG
2006 Wrangler Rubicon
1966 230SL auto "Italian"

lpeterssen

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Re: Coil / Resistor wiring plus Bosch gizmo near coil
« Reply #2 on: August 31, 2024, 10:34:42 »
Dear friend

That 4 prong connector attaches to that rectangular silver thing which is a RELAY.

It is needed a photo of the connector opened to look the position of the cables, and in that way have an idea for what service or function it is used that relay in your electric arrangement.

In principle I do not think is related to the ignition, but you never know.

There are full diagrams of the electrical wiring of your car on the technical section of this forum. They are very usefull.  I think you have to become a member to access them, which cost only 30$ annually.  Believe me it is worth the investment.

A relay has 4 terminals in principle.  The control terminals are numbered 85 and 86.  The brown cable in your connector should be on the pin 85, (- signal).  On the port 86 you need a positive activation signal.

Then ports 30 and 87 are what is called the switched circuit.  Port 30 is the source signal which has usually a thick cable, and port 87 is the output switched signal.   Port 87 has current only when control terminals 85, and 86 are excited at the same time.  I mean port 85 is connected to ground and port 86 to a positive trigger source.

Have a great day.

Best regards
Eng. Leonardo Peterssen
Www.wiredoktor.com


lpeterssen

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Re: Coil / Resistor wiring plus Bosch gizmo near coil
« Reply #3 on: August 31, 2024, 10:42:05 »
If you are reversing the system to work with ignition points instead of electronic ignition…..

T15 hot feed cable when ignition switch is on, goes first to your external resistance.   From the output side of the coil resistance you feed the positive terminal of the ignition coil.  Is a kind of lace up arrangement.

On an electronic ignition system the external coil resistance is by-passed.

Best regards
L.peterssen
Www.wiredoktor.com
« Last Edit: August 31, 2024, 16:13:02 by lpeterssen »

230S-111.010

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Re: Coil / Resistor wiring plus Bosch gizmo near coil
« Reply #4 on: September 03, 2024, 15:00:52 »
Thanks - I figured that out as well.  It's to bypass the resistor during starting for a hotter spark.  Had disconnected w/ the old Pertronix setup b/c not needed and just couldn't recall how wired!
1966 230S
1998 C43 AMG w/ 5.4, Wavetrac LST, 6 MT
1959 190SL - sold