Lost all power need help

May or may not not be a coincidence.
Points and Chrysler type electronic ignitions both use the ballast resistor as part of the run circuit. In other words, power to the ignition goes through the ballast when the ignition switch is in the run position.
In the upper left of the 67 Run charge Diagram the dashed blue line is the Run power. Then it goes through the resistor to the coil.

Yea well I've been reading too many badly done ammeter bypass threads so I won't even begin to guess what happened in your case. That's one of the things I don't like about the MAD suggestions with respect to the a-bodies and the full size jeeps. It's why I reprinted Nacho's stuff, with some editing better english. LOL, and now some additions. IMO its clearer on troubleshooting and also more mopar specific. Just finished dealing with a 'bypass' thread in the IFSJA forum some guy innocently revived. It did just the opposite - putting all of the current except charging through the ammeter :eek:- but it had nice pictures. :BangHead: Sorry, getting OT here. Point is you'll have to check the routing to see if it makes sense.

No it will not burn up because its an original link. If its been in an environment where it got oxidized (green stuff on the copper) or physically damaged, then it would fail more easily, but not age alone.
It will melt because too much current is being drawn through it.
* This could be because of a short, which is its job.
* This could be because its carrying more current, for longer lengths of time, than it was designed for. It gets really hot but doesn't fail. Then repeat the next time, and repeat until it does fail.
For example wiring EFI equipment onto the battery terminal forces the fusible link to carry all the current for recharging the battery - done in a few minutes, plus all of the current for the fuel pump, injectors etc. full time. Either one of those alone might be ok. Together that 16 gage or even 14 gage wire becomes resistance.
That's the point of the bottom diagram on Fusible Links in Charging Systems with Ammeter

You can use a circuit breaker for testing and save the fusible link for actual use.