My son and I discovered that the fusible links for the head lamp doors and fog lights on his '86 Trans Am project had been removed by one of it's previous owners and replaced with a single piece of regular wire. We would like to repair this correctly before the car is back on the road, but I'm having some difficultly figuring out exactly that the current "correct" repair is.

Here's the mess that we found. It was wrapped in duct tape and hidden inside the plastic loom.



It's seems there are differing opinions about whether or not it's ok to replace fusible links with standard fuses. Many argue for fusible links due to their "slow blow" design that provides the ability to withstand an overcurrent situation for longer...but based on my research, fusible links should be size 4 sizes smaller than the main wire...so 22 ga fusible links for the 18 ga wire used for both the head lamp doors and fog light circuits. That being said, 22 ga fusible links are pretty much non-existent now. If those are the correct repair, I'm thinking my only option is try to find good ones in a junkyard.

This is part of a wiring diagram from an '88 Firebird, but it shows fusible links for both the head lamp doors and fog lights. According to the symbols section, the .8 and .5 indicate wire size (in sq mm I think) and based on this Delphi publication, that translates to 18 and 20 ga fusible links...which are available.


On the other hand, if standard or MAXI fuses are the best option, how should I go about determining what size fuses to use for each? Our Haynes manual states that the fog lamp circuit should be protected with a 20A fuse in the fuse panel. It's not, but maybe that gives the answer for the fog light fuse size...

Any suggestions? Thanks!

 

The Firebird headlights in 86 and 88 are not the same system and I doubt the fog lights are either. ( Maybe that's why the size of the fusible links changed from 86 compared to 88. ) Always try to find schematics that cover your exact year to be sure that your getting accurate info to work from. This scan comes from the 86 Firebird Shop manual and shows all 3 fusible links your asking about as well as the proper wire colors and specs.



Factory wiring = 1mm RED power wire / 18 gauge wire,..... 4 sizes larger for fusible link = 22 gauge fusible link. ( shown as .35mm fusible link on schematic.)

Now, you knew all that & you already know they are new impossible to find new so you probably already know what I'm gonna' say; If you want 22 gauge fusible links,... it's time to plan a trip to the junkyard !! ( I would use fusible links - even used ones - if that's what was originally installed on that those circuits, but that's just me ! )