Start Relay in a 69 stray wire??

[Classic]

Continuing on my exploration of a 69 Porsche's electrical wiring without a definitive wiring diagram.

I've concluded that the fuel pump runs from the Y connector un-fused from the switched ignition (red wire ) from the main harness. Which is also connected to the Bosche CDI.

What has got me stumped though is the "Start Relay" I have a stray red wire form 87 on the relay (so switched) which is red.

For the life of me I can't work out where it should be terminated......looking back through my old photos from when I removed everything it appears that it was just laying there not connected to anything?

I've fixed all of the PO's adventures into automotive electrical wiring ( including the use of tin foil, and granny knots to join wires).

HELP!

[911pcars]

Unless you have a T manufactured late in '69, US models were factory-equipped with a basic induction ignition system (coil and points). Perhaps a PO installed a Bosch CDI box and didn't connect the circuit to factory specs.

Here are some early wiring diagrams that might be of some use in dissecting your wiring circuits:
PorscheWiringDiagrams

Hope this helps,
Sherwood

[Classic]

[Classic]

Sherwood,

Yes it's a late 69 build with the factory option for the CDI, but from research ROW didn't get the emission relay or the slow start relay.

The car left the factory without a radio, hence the direct VR hookup.

I've got the wiring diagrams, but SL33 and 35 don't really fit the 69T.

[gsjohnson]

The red wire from 87 connector on the relay should go to the fuse block...if that helps you.

[911pcars]

Originally Posted by Classic

Sherwood,

Yes it's a late 69 build with the factory option for the CDI, but from research ROW didn't get the emission relay or the slow start relay.

The car left the factory without a radio, hence the direct VR hookup.

I've got the wiring diagrams, but SL33 and 35 don't really fit the 69T.

The various early wiring diagrams and MY 911s overlap somewhat. I've found that matching the number of fuses in a wiring diagram with the number in your chassis helps identify the applicable wiring diagram to reference.

Why connect the radio directly to the voltage regulator instead of the existing wire path in the factory wiring loom (I recall it's light blue with a spade connector). That's a lot of excess wire running to the engine compartment when a more convenient source is in the trunk (battery/fuse box).

As an aside, I hope the photos represent an interim stage in your wiring project. Suggest routing the wires as close to a factory (or equivalent) look as much as possible. I award multiple points for neatness.

Sherwood

[SCadaddle]

For what it's worth, my 69 912 has a spare wire in the left rear corner near the voltage regulator that a knowledgable P car tech showed me when you touch it to that connection with the red wires it will power the starter in lieu of the tech jumping in the car to crank it.

[Classic]

Originally Posted by 911pcars

The various early wiring diagrams and MY 911s overlap somewhat. I've found that matching the number of fuses in a wiring diagram with the number in your chassis helps identify the applicable wiring diagram to reference.

Why connect the radio directly to the voltage regulator instead of the existing wire path in the factory wiring loom (I recall it's light blue with a spade connector). That's a lot of excess wire running to the engine compartment when a more convenient source is in the trunk (battery/fuse box).

As an aside, I hope the photos represent an interim stage in your wiring project. Suggest routing the wires as close to a factory (or equivalent) look as much as possible. I award multiple points for neatness.

Sherwood

Thanks Sherwood, I've been jumping between SL33 and SL35 as 35 to match the wiring and components that my car has/doesn't have. Both have extra fuses in the engine bay compared to the T's standard 2 fuses.

The car didn't/doesn't have a radio, so the alternator connects directly to the VR. It may have been a ROW thing, as I've only seen the suppressor on US cars with the radio.

And yes it's at an interim stage, with all the wires pulled out for the photo, and not set in any of the metal tangs.

SL33 has two reds 30( I assume power) from the main harness, and 86 which is switched to 87. Which appears to go to the MFI Start Switch, which my car doesn't have.

[Classic]

Originally Posted by gsjohnson

The red wire from 87 connector on the relay should go to the fuse block...if that helps you.

Thanks, should it go to the rear window heat fuse, or to the other one?

[Classic]

Originally Posted by SCadaddle

For what it's worth, my 69 912 has a spare wire in the left rear corner near the voltage regulator that a knowledgable P car tech showed me when you touch it to that connection with the red wires it will power the starter in lieu of the tech jumping in the car to crank it.

Interesting, as from my original photos befor the resto I can see it just laying there not connected. Considering some of the things the PO did to the wiring, I was concerned that it should be connected.

Maybe power for the Sporto?