What would cause my brake light and gauge lights fuse to blow? I put the car in reverse and it blew! As you can see in my picture, I upgraded to the blade style fuse box. The fuse missing is the 20 amp that keeps blowing. The car is a ‘73 240z.

I had an alternator that popped mine. It was a reman from a chain store. The smart electrical guys on here said it was "back charging". Took it back, they tested it and it showed BAD. Gave me another one and so far so good.

Edited 9 hours ago9 hr by siteunseen

Did the problem show up immediately after the new fuse box? More detail might help. The wiring diagram doesn't seem to show any connection between the reverse lamp circuit and the brake or gauge lights. They do all have a fuse though. The fuse box seems like the common element.

Also, the FSM shows a different wiring scheme for automatic compared to manual. Body Electrical chapter. Accessory Relay and Inhibitor Switch.

p.s. do the reverse lights work? They're on a separate fuse right? Can't find an illustration of the fuse box.

Edited 4 hours ago4 hr by Zed Head

p.s. 2 - check the reverse light sockets to see if they're melted and shorting to ground. I had one do that. Not reverse but a tail light socket. They get crusty and resistive and produce heat.

I’ve had the new fuse box for several years before this problem happened. My reverse lights work.

The problem is intermittent. Also what is the proper route for the choke cables?