73 wiper motor short (1 Viewer)

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I need a little advice on where to start on a short at the wiper wash fuse. I've recently brought my wiper back to life. Although the wiper is now working perfectly, I cannot find the source of a short somewhere in the harness. The reason I believe it's in the harness is because I unplugged switch from harness and still get a short at the wiper fuse when I turn the ignition key on. If any one has a idea where and how to track down the problem I sure would appreciate it!!

Thank you
Btbuild

IMG_0577.JPG
 
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I also separated wiper harness from main harness and checked thoroughly. Still getting short. Also checked across all fuses with ignition key on and the wiper fuse block is the only one that registers 12.36 amps. I really am a dummy when it comes to electrical... ugh.

If this helps I also checked all lights, blinkers, heater fans, all work
 
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ginmtb

'74 FJ40 - my first!
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Did you check where the wiper motor wires pass through the windshield frame? Perhaps the rubber grommet isn’t there and the wire has rubbed through the insulation?

Also, those wires go through the tub/cowl - the rubber grommet in there likely is disintegrated so you may have some issues there. Fold down the front windshield and you will see how that works. If you check out my build you will see my solution for that grommet.
 
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Did you check where the wiper motor wires pass through the windshield frame? Perhaps the rubber grommet isn’t there and the wire has rubbed through the insulation?

Also, those wires go through the tub/cowl - the rubber grommet in there likely is disintegrated so you may have some issues there. Fold down the front windshield and you will see how that works. If you check out my build you will see my solution for that grommet.
Yes I have checked that already. I even unplugged the wiper harness just to make sure. I have been watching your build and did see your solution on that grommet.

It's frustrating getting toward the end of a build and finding a little gremlin after you think you checked and double checked everything.
 

ginmtb

'74 FJ40 - my first!
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You should check for continuity of the wires that go to the wiper motor. Should be easy to do if the harness is easily separated.
 
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You should check for continuity of the wires that go to the wiper motor. Should be easy to do if the harness is easily separated.
Yes that's the first thing I checked. I believe the problem is between the fuse block and battery. My ignition switch is brand new
 

ginmtb

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Looks like that fuse controls a few other things - not sure this is the correct fuse block for our older vehicles with the top mount wipers:

8B93968B-C420-423F-B541-F86F8FF65CBE.jpeg


Do those devices work okay?
 
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Looks like that fuse controls a few other things - not sure this is the correct fuse block for our older vehicles with the top mount wipers:

View attachment 1580769

Do those devices work okay?
The radio is not hooked up and the washer bottle is disintegrated. I will double Check those connectors and make sure they are not in contact with something or fried.
 

thebigredrocker

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I had to pull my old switch apart and clean it up. Also scuffed up the backside of the dash, it’s my understanding the wiper switch grounds to the dash.
 
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I had to pull my old switch apart and clean it up. Also scuffed up the backside of the dash, it’s my understanding the wiper switch grounds to the dash.
Hmm I did not know that the switch grounded to the dash! The fuse is still blowing with switch disconnected though.
 
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Well.. I'm getting 12volts across the wiper fuse posts with ignition on. I'm not sure it that's good or bad. Also washer wires are just unplugged not grounding any where same with radio.
 

ginmtb

'74 FJ40 - my first!
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Well.. I'm getting 12volts across the wiper fuse posts with ignition on. I'm not sure it that's good or bad. Also washer wires are just unplugged not grounding any where same with radio.

Any rogue wires connected on the back of the fuse box? I can’t remember to which fuses but there are tabs on the back that can be used - I know I used them for a couple of my extra electrical needs.
 

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