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Mike V.
Mike V., Auto Technician
Category: Chevy
Satisfied Customers: 23626
Experience:  25 years automotive experience, Certified Subaru Tech and Nissan factory trained.
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Fuse blowing when shifting into reverse. (1992 Chevy C1500,

Customer Question

Fuse blowing when shifting into reverse.
(1992 Chevy C1500, 5.7L, 5spd manual)
When I engage the shifter into reverse the fuse for TURN B/U instantly pops. Turn signals work with no issues when the fuse is good.
Another symptom is that when I turn the running lights & headlights on, the backlights for the dash turn off. Headlights and running lights do actually come on though. Also with the key out the warning buzzer that reminds you to turn off your headlights does not sound anymore. Dimmer switch is all the way up.
So far I have traced the reverse light wires from the transmission up to the firewall with no visible shorts. Traced it through most of the frame rail loom with no visible shorts. Also I disconnected the harness junction under the tailgate where it "Y's" off to the two taillight looms, the fuse still pops.
Any help would be greatly appreciated.
Submitted: 22 days ago.
Category: Chevy
Expert:  Mike V. replied 22 days ago.

Hello and thank you for your question!
My name is ***** ***** I will be assisting you with your question today.

Expert:  Mike V. replied 22 days ago.

If you unplug the backup light switch on the transmission, does the fuse still blow?

Do you have a trailer hitch and wiring on this?

Customer: replied 21 days ago.
Hello Mike,Thank you for your help with this.I do indeed have a trailer hitch with wiring. However I completely disconnected that and the fuse still popped.I unplugged the backup light switch yesterday and the fuse does not pop any more. The dashboard backlights still turn off when the headlights are turned on though.
Expert:  Mike V. replied 21 days ago.


So I know you have checked the wiring from the tail lights. If the wire going to the switch is or was grounded out, it should still pop the fuse. Try unplugging the rear light sockets themselves and see if it stops blowing the fuse. The issue could also be the switch itself. IF you can do it, run a power wire to the tail lights right off the switches connector on the harness. If there isn't a problem, you should get the backup lights working.

I will help you with the dash lights also, but one step at a time. We get the back lights working properly, find the source of the problem, it might resolve the other light issue.

Let me know.


Customer: replied 20 days ago.
Okay, I will run power to the switches connector on the harness as the next test. I never thought about the switch itself potentially being bad. Sorry for the long delays in my responses back, I don't have a lot of free time due to work.
Expert:  Mike V. replied 20 days ago.

Its really no problem, hopefully it will be something like the switch causing the problem. I understand working, so please reply when you can and we can go from there.