That old melted fuse box question - with a small twist . . .

[Guest Madeline Larson]

So, I'm new to restoring vehicles, and I'm getting ready to start working on my dad's '71 240z. Lo and behold, one of those problems is a fuse box that is melting due to corrosion on the contacts. My question is this:

 

- What exactly is causing the corrosion? I have a replacement box, but I don't want to drop it in and then have the same issue occur all over again because I never took care of the actual problem.

 

I've seen that many people are going through and replacing the wiring harness. Is the original wiring still ok, should I be looking into replacing it simply because it is 37 years old? For what reasons would I need to replace the existing harness?

 

--- Madeline

[Daeron]

Over time, countless solder connections in the entire vehicle's wiring wind up being the primary points of random, background resistance that builds up with age. However, the copper itself is also potentially liable to corrosion.

 

In short, (no pun intended) you could either...

 

..perform a series of meticulous and tedious continuity checks, and drive yourself crazy reading wiring diagrams just to make sure you know what should go where...

 

..just work with what you have, dovetail the new fuse box in, and do an empirical evaluation of the state of the wiring harness (how bright and even are the headlights? interior lights bright enough?)

 

..or you could go ahead and swap in the "Painless" wiring harness.

 

In any case, a thorough visual inspection of the exposed bits of the harness will begin to tell a tale, if it has reached a critical state.

 

So, take a look at it, and good luck with your decision. Time will tell; but be ware: putting off electrical issues for TOO long CAN result in FIRE! (click "fusible links blow" in my sig for a long, LONG story explaining one way how.)

[NCchris]

Daeron is spot-on! You may also want to examine all the under hood wiring as the Z's engine room temps get pretty hot. All those components, insulation, and connectors etc. being cooked for 30+ years takes it's toll.

[gogriz91]

MSA is selling a more modernized fusebox in their catalog and on EBay if your comfort level with your replacement box isn't that comfortable.