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Discussion Starter · #1 ·
While doing some research in Opel wiring diagrams for another switched 12V source, I happened upon this little wiring anomaly between the '68 and '69 wiring diagrams, so let me pose this here as a little brainteaser.

What is the only wiring change between the '68 and '69 model year wiring diagrams? Hint: think starting circuit . . . :confused:
 

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well if I were to take a guess in 68 a GT was 1.9 0nly but 69 had the 1.1 available so the starter wiring is on the other side and uses different wires?
BTW delivery was confimed, Thanks Otto.
 

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Discussion Starter · #3 ·
Anyone else?

Anyone else want to take a stab at it . . . no prizes, just interesting. :rolleyes:
 

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Discussion Starter · #4 ·
The answer . . .

Opel changed their ignition coil + wiring from full switched 12V source at all times in '68 to full switched 12V during start only (direct connect, second wire from starter solenoid) and resistance wire connection (~9V) at all other times (ignition on/run mode) in '69 . . . at least according to published wiring diagrams.

That means that they used an internal resistance coil, like the Bosch "blue" coil and most aftermarket replacement coils, in the cars prior to the '69 models and non-resistance coils from then forward. Anyone have a '68 or earlier model that can verify this . . . 2 wires (black/clear) on coil + connector? :confused:
 

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yup

Both my '67's, the Kadett and the Admiral are wired without the resistor wire, full 12V to the coil. Can't vouch for the GT's, but probably the same deal.
 

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Discussion Starter · #6 ·
'68 GTs probably N/A

oldopelguy said:
Both my '67's, the Kadett and the Admiral are wired without the resistor wire, full 12V to the coil. Can't vouch for the GT's, but probably the same deal.
This doesn't really apply to any GTs, since the relatively few actual '68 GTs (31) were dealer demo models and weren't released until 3rd quarter of '68 anyways. For that reason, I believe they were all wired like the '69 models.
 

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Heh, heh, I knew the answer
I found out the hard way when I was poor and swapping parts from car to car.
My 69 was an early model and didn't have the resistor installed. So when I took the coil out of a wrecked GT and put it into mine I had this stupid little thing that pissed me off.
I would start and drive fine, then all of a sudden the car would die. Turns out I needed a ballast resistor installed.
Worked perfect after that.
 

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Otto, That was going to be my guess. No, honestly, I knew that.

I was actually sorting through some Opel Technical Service Bulletins over the weekend. There is one that talks about this & also shows pictures on how to identify the different factory Bosch coils.

~ Tom C
 

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Discussion Starter · #9 ·
Very useful info . . . already added to my collection.

Mach1Tom said:
Otto, That was going to be my guess. No, honestly, I knew that.

I was actually sorting through some Opel Technical Service Bulletins over the weekend. There is one that talks about this & also shows pictures on how to identify the different factory Bosch coils.

~ Tom C
Thanks, Tom . . . very useful info to add to my collection. :)
 
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