1970 AristoCraft Restoration

Bourbon1792

Recruit
Joined
Sep 26, 2021
Messages
5
I am near completion of phase 1 of my restoration project and have run into a problem.

During the restoration of the instrument panel, I discovered many of the wires disconnected or modified. Although I have an OEM maintenance manual, the wiring diagrams do not match my instrument panel. My greatest concern is how the coil wire (purple) is connected to the ignition. It appears that the purple wire was attached oil pressure gauge and then, a jumper to the ignition.

Problem: The engine cranks when the key is turned, but no spark. I gone through all "no spark" trouble shooting procedures and voltage test of ignition components. I am concerned that the problem relates to improper wiring from the coil to the ignition switch. A detailed wire diagram for the instrument panel would prove very beneficial. Thoughts? Advice?
 

briangcc

Commander
Joined
Jul 10, 2012
Messages
2,429
There isn't one for your 51 yr old boat. In fact, I'd wager it has been "victimized" by one or more backyard "mechanics" who took turns with "hold my beer, I go this" as it was rewired in an attempt to "fix" a various problem.

Your best bet is to start tracing wires and see where they lead to.

The guys/gals might be able to help you more if they knew what year, model, and HP engine is involved...wink, wink...
 

Bourbon1792

Recruit
Joined
Sep 26, 2021
Messages
5
There isn't one for your 51 yr old boat. In fact, I'd wager it has been "victimized" by one or more backyard "mechanics" who took turns with "hold my beer, I go this" as it was rewired in an attempt to "fix" a various problem.

Your best bet is to start tracing wires and see where they lead to.

The guys/gals might be able to help you more if they knew what year, model, and HP engine is involved...wink, wink...
Good Evening and thanks for the advice.

It is a 1970 AristoCraft 19" with a 120 HP Mercruiser GM 4 cylinder.

I finally found a proper wiring diagram and was able to correctly wire the control panel and ignition switch. The boat cranks but no spark.

During the renovation I did replace the coil. distributer cap, points, condenser, spark plugs and wires. When I conduct a voltage test on the positive side of the coil, with the points closed and key on it reads 4.3 volts. Ironically, it reads the same when the points are open. I thought it was supposed to read 12 volts when the point are open.

Thoughts or ideas are greatly appreciated.
 

matt167

Rear Admiral
Joined
Sep 27, 2012
Messages
4,202
Points switch the ground, you should always read at least 6v at the coil but really should be closer to 9v while running, in general... Take a jumper wire directly from the battery to the positive side of the coil and see if it will generate spark.
 

Bourbon1792

Recruit
Joined
Sep 26, 2021
Messages
5
Points switch the ground, you should always read at least 6v at the coil but really should be closer to 9v while running, in general... Take a jumper wire directly from the battery to the positive side of the coil and see if it will generate spark.
Good Morning.

I just tested a jumper wire directly from the battery to the positive side of the coil and did generate spark.
 
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