Wiper fuse keep blowing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1SG.Rob · 12-18-2017, 04:43 PM

This weekend I replaced the in-dash main wiring harness. It cam with a brand new fuse box and all the wires to OEM specs. We got it installed but every time we turn on the ignition, the fuse for the wiper motor blows. Even when the plug going to the wiper switch is not attached. Any ideas? I am a novice at best when it comes to electrical systems. My worry is that the new fuse box is bad and I will have to replace it. Thanks!

71meangreenc10 · 12-18-2017, 04:50 PM

Unplug the wiper motor itself. The switch provides the ground circuit for the wiper motor if I am correct.

http://67-72chevytrucks.com/vboard/s...d.php?t=584603

Smitty

1SG.Rob · 12-18-2017, 05:12 PM

Why would replacing the wiring harness change anything or cause the short? The wipers worked just fine before I replaced the wiring harness. I didn't replace anything going to the wiper motor, just the wires to the switch.

harpo231 · 12-18-2017, 05:20 PM

Sounds like something new is bad

71meangreenc10 · 12-18-2017, 05:20 PM

Quote:

Originally Posted by 1SG.Rob

Why would replacing the wiring harness change anything or cause the short? The wipers worked just fine before I replaced the wiring harness. I didn't replace anything going to the wiper motor, just the wires to the switch.

Maybe that harness has a hot circuit instead of a ground going to the switch. Time to get a test light or a multimeter out.

If it is an aftermarket harness, it may be wired to what most people think of as hot when a switch is used. That is not how this circuit was designed. Unplug the wiper switch and the motor and probe the circuit to see how the new harness is sending 12v. Sounds like a hot is going into the ground side at the motor. Check the link I sent you to see the differences.

Smitty

1SG.Rob · 12-18-2017, 07:09 PM

Thanks for the advice and help. After reading that and then remembering to account for the fact that I'm a dummy, I saw that I had plugs going to the wiper motor in backwards. Switched them around and now the wipers work like new. Thanks again, Smitty.

71meangreenc10 · 12-18-2017, 07:14 PM

Quote:

Originally Posted by 1SG.Rob

Thanks for the advice and help. After reading that and then remembering to account for the fact that I'm a dummy, I saw that I had plugs going to the wiper motor in backwards. Switched them around and now the wipers work like new. Thanks again, Smitty.

No problem,

We all have those moments....

Smitty

12-18-2017, 04:43 PM	#1
1SG.Rob Registered User Join Date: May 2017 Location: Vancouver, WA Posts: 87	Wiper fuse keep blowing This weekend I replaced the in-dash main wiring harness. It cam with a brand new fuse box and all the wires to OEM specs. We got it installed but every time we turn on the ignition, the fuse for the wiper motor blows. Even when the plug going to the wiper switch is not attached. Any ideas? I am a novice at best when it comes to electrical systems. My worry is that the new fuse box is bad and I will have to replace it. Thanks!

12-18-2017, 04:50 PM	#2
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,158	Re: Wiper fuse keep blowing Unplug the wiper motor itself. The switch provides the ground circuit for the wiper motor if I am correct. http://67-72chevytrucks.com/vboard/s...d.php?t=584603 Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 71 C20 Longhorn/Ole Yellor 69 C30 Former Motor Home, Flat Bed time Last edited by 71meangreenc10; 12-18-2017 at 04:56 PM.

12-18-2017, 05:12 PM	#3
1SG.Rob Registered User Join Date: May 2017 Location: Vancouver, WA Posts: 87	Re: Wiper fuse keep blowing Why would replacing the wiring harness change anything or cause the short? The wipers worked just fine before I replaced the wiring harness. I didn't replace anything going to the wiper motor, just the wires to the switch.

12-18-2017, 05:20 PM	#4
harpo231 Registered User Join Date: Nov 2014 Location: Lincoln City DE Posts: 1,292	Re: Wiper fuse keep blowing Sounds like something new is bad __________________ Stan 67 swb BLU MULE posted via flip-fone

12-18-2017, 07:09 PM	#6
1SG.Rob Registered User Join Date: May 2017 Location: Vancouver, WA Posts: 87	Re: Wiper fuse keep blowing Thanks for the advice and help. After reading that and then remembering to account for the fact that I'm a dummy, I saw that I had plugs going to the wiper motor in backwards. Switched them around and now the wipers work like new. Thanks again, Smitty.



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