Blowing fuse

[joe newsom]

Hi guys, I know there is wiring diagrams for research. Which I have looked at. I have a circuit that keeps blowing a fuse.

The scenario is that I have a 71 240z

I switched from automatic to manual ( I don’t this this is related)

I keep blowing the Domelamp/Luz/instru circuit when I press the washer button. I believe this the instrument cluster as well who’s the only movement from gauges is the amp while trying to start.

The wire coming from the fuse box looks to be red with blue.

 

If anyone has any suggestions of where to look that would be most helpful.

 

 

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[Patcon]

@SteveJ

[joe newsom]

Is there a way to test the switch if is shorting out ?


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[zKars]

Start by disconnecting the washer motor, and testing if the fuse blows or not. If not, the fault is in the washer motor. If it still blows, the problem is between the washer button and the connectors to the washer motor

[joe newsom]

I have found the connection to the washer from the switch. Is there and grounding concerns on the column or special way to connect the the switch to the column? Should there be a bushing or tape so the whole switch doesn’t touch the column?


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[SteveJ]

The problem isn't likely to be the switch itself. The first thing I suggest is disconnect the wires from the motor on the washer pump. There should be a black wire and black/yellow wire. Use a multimeter set to resistance and touch the leads to each wire. If the resistance is low (like less than 10 Ohms), the problem is in the wiring. If the resistance is high, then the problem is with the pump motor.

If it's in the wiring, find the connector highlighted in the attachment and separate it. Repeat the test at the wiper motor. If the resistance is low, the problem is in the engine harness. If the resistance is high, the problem is between the instrument harness and the switch.

[joe newsom]

The switch is definitely shorting on the column. Not sure about bushings. Her are some pics of what I have going on.


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[SteveJ]

I saw nothing in the photos to support evidence of the switch shorting on the steering column.

Here's a video I just made of a 240Z headlight switch to show the wires for the washer and how it works. 

 

I also attached a couple of photos for additional clarity. Please notice that the contacts for the washer switch are insulated from the screws holding them in place.

Have you tested with a meter to see if the blue/white wire is grounded out? How about the blue/red wire? 

 

[joe newsom]

Steve I am noticing when I don’t have the switch attached to the column it works great. It seems that I may be missing some idolaters because it not movement of the switch touching the column it’s the brass corners. Thank you very much for you video and time


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[joe newsom]

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[SteveJ]

48 minutes ago, joe newsom said:

Steve I am noticing when I don’t have the switch attached to the column it works great. It seems that I may be missing some idolaters because it not movement of the switch touching the column it’s the brass corners. Thank you very much for you video and time


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I took a closer look at one of your earlier photos. It certainly does look like you could be missing the insulators on the side of the switch that is toward the driver. These insulators are more than just washers. They go through holes on the contact plate to isolate it completely from the screws and rest of the switch.

[joe newsom]

Steve I was hoping to pick your brain about a couple connections as well.
I am having struggles remembering exactly where all connections went under the dash at the console. And unfortunately I did not take enough photos.

My question is about the short wire harness from the blower the switch on the console.
I have photo shopped a picture labeling connections that I know and the ones that I can’t seem to find on the wiring diagram. I can not seem to locate the blower on the diagram. I will include a pic of the one I am using. Maybe you could be so kind to point out what I am missing?
The blue wire I think goes to a relay undo passenger side of the dash.
The black is grounded, and the two 6 pin plugs go to switch and blower. The rest I have know idea :/


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