Wiper and reverse light help

[tat2matt]

1985 j60, First my reverse lights went out then I started blowing the wiper fuses. At first they blew now and then after a few month's ( not my daily driver) the fuse would blow as soon as I started the truck. I have checked the wiper relay and it's good. I have unplugged the reverse light switch and the wiper motor and it still blows. I can't seem to find a short anywhere but it seems to be a dead short as soon as I turn on the ignition. Any help would be greatly appreciated. I'm leaving for Colorado in 36 hours and it would be really nice to have wipers.

 

[John McVicker]

The wiper is on the same circuit as the green 4wd dash light (don't know about the reverse light). This switch is located on the t-case on the US passenger side. Have to crawl under the truck. Look at the wiring around this switch to see if anything is frayed & causing a short.

This was my problem when I was blowing fuses every time I turned on the wipers.

John

 

[tat2matt]

@John McVicker I tried disconnecting that actually and still same result. Mine blow when the wipers are not on just as soon as I turn on the ignition. Thanks for the suggestion. BTW there was an Earl McVicker in Humboldt years ago, super great guy,one of the very best hope you two are related case he's a gem.

 

[John McVicker]

Sorry that doesn't solve your issue. Not too many McVicker's around. To my knowledge no relatives over in Humboldt Co.

I'd check the FSM & see what else is on that same circuit, could still be a bare wire on the wiring to that T case switch, I think it would be 'hot' as soon as you turn on the key.

John

 

[Output Shaft]

I would start looking for frayed insulation shorting a wire against body ground somewhere.

Sometimes these things can happen when some other non related task was being performed on the car that inadvertently misalignes something or another causing chafing on a wire.

Think back about any mods you've done recently & in the past that could have accidentally changed something to chafe on a wire.

Maybe not. But worth considering.

 

[db3]

If you have a test light, wire up a spade lug that will plug into your fuse block. Connect one side of the test light to the battery and connect the other to the spade lug in the fuse block circuit which is blowing. The lamp filament will protect the wiring, and allow you to troubleshoot. Since you have already disconnected the wiper and the back up lights, either there is some thing else on that fuse circuit which needs to be disconnected (check your FSM wiring diagram), or a grounded wire. Wiggle the wiring while watching the light. If it flickers or goes out, you have at least isolated the problem. If you happen to have a low reading DC clamp on meter, you can check wires for current flow to further isolate the problem.

 

[tat2matt]

Thanks Guys, I ordered a DC amp clamp and will try and isolate more from the road. In the mean time I wired the wipers thru a new fuse and a switch on the dash. Should at least get me thru to colorado and I will go from there.