1969 Chris Craft Roamer Refit: Engine Wiring III

Well, it’s getting hot in the tent again, so I’ve been spending more time than I’d like making hatches and vents. Cutting holes in shrink wrap is easy, but each opening weakens the skin unless it’s secured by battens to some sort of framing. When I’m not ventilating the tent, I’ve been working on getting the engine wiring done. The battery cables are mostly installed, and I’m getting close to having the Cummins OE wiring interfaced with the OE Chris Craft wiring.

New hinged tent vent opens to catch southerly breezes

The new vent helps, but I’ve got to open up the top of the tent somehow. Heat rises, and it’s still scorching up above the deck level. Meanwhile, down in the engine room…

Somebody’s been in the port engine starter/alternator loom before

On the port engine, the starter loom isn’t neatly run between the starter and block. The untrimmed zip tie secures the loom to the turbo oil return line, which is fine, but I’ll repeat what I did on the starboard engine wiring and replace the original Cummins alternator wire with a much heavier #6AWG wire, re-routed to accommodate the OE Chris Craft ammeter shunt.

New 6AWG +12v cable from the alternator

Ready to install

That’s a proper wire for a 100+ amp output alternator

Stuffing the fatter loom behind the starter and down to the aux. starter solenoid took a bit of work

But it’s a much cleaner installation

Alternator wire trimmed to fit the shunt, then new wire up to the starter + terminal

Interfacing the Chris Craft and Cummins wiring

The #8AWG red Chris Craft wire on the left supplies power to the port 12v breaker panel, which is now connected to the battery terminal on the starter and the Cummins alternator via the the Chris Craft shunt. The green Chris Craft starter wire is connected to the 12v+ side of the aux. starter solenoid. I’ve been thinking for a while that I’d like to install a neutral safety switch. I’ve never started a boat that was in gear, but I’ve been on one where that happened and there’s nothing quite like a 900hp boat trying to take off while still attached to the dock! Neutral safety switches are a good upgrade. It looks like the Cummins loom uses switched ground for neutral safety, which will work well with the Chris Craft wiring.

Chris Craft shunt wiring is attached and trimmed zip ties secure all of the wiring

There was less “extra” shunt wiring on the port side; a couple of loops  take up the excess

On the starboard side, I put glued shrink tube on all terminals and attached the negative battery cable to the block

That pretty much wraps up the Chris Craft side of the wiring. Next I need to dig into the Cummins looms and clip wires to size, come up with neutral safety switches, and then install the Chris Craft oil and water temp senders and alarms on the Cummins blocks.

Next up on our 1969 Chris Craft Roamer Refit: Engine Wiring IV