Overdrive electric circuits

[John Quilter]

1965 MOD full syncho gearbox car. My overdrive stopped engaging, no light on the steering column nacelle, no click from solenoid. Put car in 4th, ignition on did some trouble shooting and found the lever switch worked as I had power at a yellow wire on one side of a bullet connector under the dash. Tested the solenoid with a jumper wire directly to the bullet connector under the car coming from the unit. Solenoid worked. No power at the bullet connector here with ignition on, switch down, and ignition on, gearbox in 4th. Tested further and found a bullet connector with yellow wire under the dash did not transfer power from once side to the other. Pulled apart, no visual corrosion but cleaned & replaced. (Should have tested BOTH sides first). Overdrive solenoid now clicks as normal. Studying the wiring diagram I see what appears to be an inline fuse. In the event I ever have to deal with this fuse, where exactly is it?

[Glyn Ruck]

Useful information. Bullet connectors can go open circuit.

[John Quilter]

So does anyone know where the inline fuse for the overdrive is located?

[cass3958]

John I have an Auto box so can't help with specifics but from my knowledge of working with my own wiring loom apart from the radio I cannot recall any inline fuses. All my fuses were/are situated behind the dash panel and all the wiring is centred around these eight fuses. Having said that looking at the aluminium plaque in the front of the fuse box there is no mention of the O/D.

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[Glyn Ruck]

It's an inline fuse usually in a red holder to protect the solenoid should it not come out of engagement current to holding current. Early cars did not have them so you burnt out the solenoids.

[John Quilter]

Glyn, That makes sense. Many, many decades ago we burned out a replacement solenoid as the installer did not understand the importance of correct adjustment. Apparently, my November 1964 build car does not have the inline fuse. I only saw it on my large color wall poster of the wiring diagram which is apparently for later cars. Thanks for your reply.

[Glyn Ruck]

A pleasure. A '64 won't have a fuse fitted. The engagement current is 20 Amps. The holding current is 1 to 1.5 Amps

BTW the pin in the hole setting is not ideal either. One needs to play around a little to ensure no slip of the cone clutch.

[John Quilter]

It's a November 1964 build car but designated as a 1965 per the VIN J-65 P1B76415DN One hundred and five VINs, i believe, after the change over to the full syncho gearbox. So the inline OD fuse must have started later.

[Glyn Ruck]

Definitely won't have the inline fuse November 64. While I replaced all harnesses my car was built early 1966. SA did not start building them until early '66 at CDA East London. I call mine a '65 because somehow it was registered on our system Dec 65. Mine was No 4 off of the local production line here at CDA. It is something I have never been able to resolve. Maybe it was registered as a pre build Demo as the CKD kits were already in SA. It was delivered straight to the Johannesburg dealer & never saw the coast again until I brought it finished down to Cape Town. Was bought new by a Doctor from that inland dealer at 5800 ft above sea level. Why it was rust free. It was always garaged at altitude in very dry air.

The S Type Register confirms this.

[John Quilter]

Mine bought by my parents in Feb 1966 with 13K miles. Always a west coast car and garaged, Zero rust. Now with 170,000 miles. Never "restored" but did get a comprehensive engine and mechanical overhaul 2 years ago. Runs and looks like a new car. In the 1960s era cars in the USA could be year model updated if still in dealer inventory when model year changed around September'October of the year. That is why the VIN has a prefix of J-65.