1966 Charger Speedometer issue

[Steve Johnston]

Hello everyone, I just picked up a 66 Charger, car was running ok, but the plugs were fouled and the carb was black. I cut to the chase and just went directly to EFI, since the engine was not original. As I continue to dig into the car, gremlins keep showing up. The lights inside the car went out, only to find out that the fuse box burned up at one point, they guy was running 30 amp fuses in everything and to get to the issue I removed the speedometer cable, which mind you was jumping around anyway and seemed to be 10-20 off. Put the cable back in and the speedo pegs to max, I take it off and the needle goes to 0 again. I reset everything and put it back on and it does the same thing.

Am I missing something? I just ordered a new cable and did notice the end of the new one was square and the old one is rounded to some extent. Thoughts?

 

[PurpleBeeper]

both ends should be square. A new cable should fix it

 

[JimKueneman]

I just got my '68 Coronet speedo fixed. A common problem is there is a plastic retainer that hold the magnets into the housing that the cable plugs into. The needle is connected to a cup that it around the magnets. When the retainer gets old and brittle it can break allowing the magnets to contact the cup. This can cause a tinny noise when they touch while moving or cause the needle to stick or bang from rail to rail.

 

[Wietse]

My speedo was jumping all over the place with "higher speeds" and basically showing nothing a low speeds.
I had it open and found the issues was the internals of the needle, the mile counter kept working properly but the "clutch" was worn out and got the problems as JimKueneman described above.
I installed a new speedometer from OER (classisIndustries) and now i have a good working speedometer.
I found the internals to fragile to work on and realized that i will never get it back to the original "friction" it supposed to give to be accurate.