Wiring harness question

[Captndrydock]

My wiring harness leading under the dash had the black wire taped back. Should it be connected somewhere and if so where? It's not really been a problem on the boat, but I do wonder if it should be grounded somewhere.

I'm currently wiring a switch to another motor on a stand and came up against the same question. Wondering if it should be grounded at the battery?

The motor on the boat is a 1977 Chrysler 135hp. Motor on the stand is a 1980 Chrysler 115hp, if that matters.

 

[Scott Danforth]

we cant see where the wire goes.
we cant troubleshoot your boat.

with your information of a black wire tapped up. we cant do much more than speculate.

so what did you do to trace the wire and determine what it is for?
did you use the chrysler schematic from their manual which would have the motor and controls wiring?

 

[Captndrydock]

Well, I'll take some pics. Let me see if I can clarify for the moment. The wiring harness coming from the motor busbar to the key switch all hook up except the black wire. It was tied back at the key switch, as there's no place on the switch for a black wire anyway. It doesn't appear to go anywhere, as it wouldn't reach the busbar under the dash.

The black wire is in the harness, and connects at the busbar on the motor, but is not connected at the other end by the key switch.

I'll look at the wiring schematic in my manual and send a pic of my wires if that's helpful.

Thanks,

 

[Captndrydock]

Fwiw, here's a pic of the wires. Both were taped back, black and purple. And a picture of the terminal block on the motor. Black wire is attached at the bottom of terminal block on motor.

My best guess is the black wire is redundant as there is already a black wire running from the negative post on the battery to the terminal block under the dash, but wanted to confirm.

But for the motor on the stand, does the black wire need to be grounded?

 

[Nordin]

The black is the negative from battery.
In the harness the black should be connect to the first (not the screw holding the terminal strip/busbar to the engine block) but next one from the bottom.
There should be a jumper (metal clip) from the mounting screw (first screw from bottom) of the terminal to the next terminal screw at the terminal strip/busbar.
If there is another wire from the battery to the busbar under the dash the black one in the harness do not need to be connected.
But you can connect it to the busbar, then you have a redundant negative wire to the busbar.
Negative wire is not needed to the keyswitch, but if you have auxiliary equipment then you need it under the dash, but there are no terminal for the black wire at the keyswitch.
BTW The purple wire is for indication of charging.

 

[jerryjerry05]

It doesn't need to be hooked to anything.
It's an extra to be used for anything you need.

 

[Captndrydock]

The black is the negative from battery.
In the harness the black should be connect to the first (not the screw holding the terminal strip/busbar to the engine block) but next one from the bottom.
There should be a jumper (metal clip) from the mounting screw (first screw from bottom) of the terminal to the next terminal screw at the terminal strip/busbar.
If there is another wire from the battery to the busbar under the dash the black one in the harness do not need to be connected.
But you can connect it to the busbar, then you have a redundant negative wire to the busbar.
Negative wire is not needed to the keyswitch, but if you have auxiliary equipment then you need it under the dash, but there are no terminal for the black wire at the keyswitch.
BTW The purple wire is for indication of charging.

Thanks so much Nordin! That answers my questions perfectly!

 

[Captndrydock]

It doesn't need to be hooked to anything.
It's an extra to be used for anything you need.

Thanks Jerry!