Wiring harness issues

[bullit1119]

I have a 1977 merc 1500 and the external wiring harness is throwing me for a loop. I lost power to motor so i started troubleshooting the problem. When checking continuity in the harness i found that my ignition wire (small red one) has continuity with the hot wire pin (no surprise there) but also with the ground wire pin. Is it safe to assume there is a short in the harmess and that i should replace it?

 

[glenn property of pam]

Re: Wiring harness issues

its hard to read continuity because the 12+ wires will read to ground if any item is attached and turned on. The meter will read via the red wire to lets say a volt meter on the gauges then via the internal coil of the gauge back to ground so a cheap meter will tell you the red is grounded. Only by disconnecting the wire both ends can you ohm to ground to see if you have a problem. use a old off cut of wire to make a jumper the you can ohm a wire to tell if its broke (like extending the leads of the meter to reach both ends of the wire)

Most of us use voltage readings to locate problems unless there a short that's blowing a fuse

 

[bullit1119]

Re: Wiring harness issues

I have both ends of harness disconnected. Nothing is hooked up and im still reading the red wire grounded

 

[glenn property of pam]

Re: Wiring harness issues

the red wire is ground to ?????? the boat or the black in the harness

 

[bullit1119]

Re: Wiring harness issues

Grounded to black in harness

 

[glenn property of pam]

Re: Wiring harness issues

any extra harness hidden up in the back of the boat?

 

[bullit1119]

Re: Wiring harness issues

Unfortunately not. I can get a new one from local shop for $145 though