1963 10 amp fuse keeps blowing or melting please help.

[Brad R.]

Hi All,

I have a wiring issue that seems to persist in terms of the 10 amp fuse at the top of the fuse panel keep 'blowing' or 'melting. Using the AIM, I can see how the wiring chases from the block and what hardware is in the loop. I recently tried to hook up my lighter ( and this is a red wire) and around that time the fuse started to fry. I disconnected it and electric taped it off so that it would not have an effect on the dash. When I replaced the fuse it melted again. As most of you know, the fuel gauge, temp gauge, and back lights do not work when this fuse has an issue. I just cannot figure out what the cause is here. I am in progress with restoring the interior and only have a few connections left to complete. The clock is not connected, the parking brake switch is not assemble to be connected, and the glove box light is not connected. All that is not connected is covered with electrical tape. If any of what I have posted makes sense to someone, please do reply with what you think I may be missing.
Many thanks

Best,
Brad

[Terry D.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

My only suggestion would be to get one of the color coded wiring diagrams and start tracing wires. You have a short somewhere and they can be a real pain. Keep us informed.

[Frank D.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Ok first off, some of the repro cigarette lighters are fire hazards and poorly designed nad 63s have No fusing in that circuit (IIRC that started in '67). See picture and I hope that's not what you're using: They can create a dead short. That center prong can get bent over and then its bad news.

Second, the glove box light is always powered and many put a bullet connector on there so that working in that area with power on doesn't create a dead short (second picture courtesy of Harry Sadlock)

I'll have to dig out my Dr. Rebuild schematic to look at some other areas and make sure the fuse you are working with is indeed for what you think its for.

[Frank D.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

OK - checking the schematic - you have it right....power comes off the ignition switch and is routed to to fuel/water gauges, dash lights, parking brake switch and to the rear harness for (I presume) back up lights at that top 10A fuse...

First, conduct a physical inspection of all the wiring at those components and look for melted, frayed, loose wires, etc. You have to have a "dead" short for that fuse to blow so swiftly.

Then I'd be tempted first to disconnect the rear harness inside the DS kick panel to eliminate an issues rearward, then disconnect the other components and replace the fuse; if it does NOT blow, then replace the connectors singly until it does - that's your issue.

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Thank you for the suggestion Terry. Per your suggestion, I just completed the tracing and have a final list of hardware in the loop.

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Hi Frank,

Thanks for the help, feedback, and pictures. I do in fact have that lighter. It came with the car when purchased and has been a concern since... Do you happen to know if it is fine to just not connect and secure the wire? I like the suggestion of adding the inline bullet connector and will do so.

Best,
Brad

[Frank D.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Hi Frank,

Thanks for the help, feedback, and pictures. I do in fact have that lighter. It came with the car when purchased and has been a concern since... Do you happen to know if it is fine to just not connect and secure the wire? I like the suggestion of adding the inline bullet connector and will do so.

Best,
Brad

You could certainly tape off the lighter power wire and be fine....its nice to have it though if you want to plug in a phone charger or other device. You could also fuse it but are better off with a less-dangerous reproduction.

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Hi again Frank,

Will do. Another thought, is it worth testing/inspecting the Pink side of the fuse? It chases through the ignition switch and looks to be coupled from the ignition switch to the coil / starter relay.

Best,
Brad

[Richard M.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

I don't have diagram handy. But IIRC that circuit also powers the Fuel Tank Sending unit.

Pull the rear harness connector apart under dash and re-fuse the 10A. Or pull Pink wire at sender.

Also, Pink to ballast/coil same circuit, but unfused, so not that.

Rich

[Frank D.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Yes the oddball powered C2 sending unit receives 12V via the rear harness connector. Hence my suggestion to disconnect it for troubleshooting.

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Hi Rich,

Thanks for the pro tip as well. I will do so and report back.

Best,
Brad



63' Daytona Blue/ Red Interior vert

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Thanks Frank. Good deal.

Best,
Brad

63' Daytona Blue / Red Interior vert

[Harry S.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

When you find the problem consider replacing the entire harness. As I recall GM gave a life expectancy of 15 years to a harness. So for safety reasons, if you think it's older than 15, replace it.

[Brad R.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Hi Henry,

I appreciate the safety check! To your point, the engine bay/ ignition harness and dash harness are 3 years old. I have not replaced the rear harness but I believe it is about 6 years old.

Best,
Brad

63' Daytona Blue / Red Interior vert

[Edward J.]

Re: 1963 10 amp fuse keeps blowing or melting please help.

Brad since it powers the gauges, did you have the cluster out and apart? I believe sometimes the studs have fiber or plastic Washers to isolate the power to the pins. Maybe Rich knows. Do you know if this problem just started with your recent work? This may give a place to start.