Replacement Fusible Links for the first-generation Mazda RX-7
This document last modified November 30, 2009.
Ron Slabach from the first generation RX-7 mailing list found this 1979 Mazda service bulletin, which describes amperage conversions for each of the different sized fusible links that Mazda used in this model:
The first gen RX-7s didn't use a red link, but other Mazda models did. The factory shop manuals show the following fusible link color codes for the 79-85 RX-7s:
All models:
Top: brown, for the headlight retractor
Middle: black, for the "main" circuit
Bottom: brown, for the headlights
The GSL-SE had two more, mounted in a separate fusible link block:
Top: green, for "injection"
Bottom: brown, for the computer
Putting the service bulletin information together with the factory shop manuals, we can see that a 12a car would need two 20 amp fusible links and one 45 amp fusible link. The GSL-SE would need these, plus a 30 amp link that is not common to the 12a cars and an additional 20 amp link.
The OEM-style wire fusible links are very hard to find at local parts stores. (Mazdatrix and Mazda dealers can get them for you, or you can make your own. See "Fusible Link Wire" three quarters of the way down the page.) Fortunately, aftermarket fuse supplier Bussman has a line of modular fusible links that seem to directly plug into the RX-7 fusible link block, and many stores keep them in stock. They also look better and are probably more reliable than the OEM wire links with cloth covers. So go to your local parts store and pick up the following for your model of RX-7:
For a 12a car:
Order two Bussman "FLF-20" fusible links and one "FLF-40."
For a GSL-SE:
Order three Bussman "FLF-20" fusible links, one "FLF-40" and one "FLF-30."
Bussman also offers the FLF-50, which I thought was just a little too
much current to replace the highest capacity OEM fusible link. The
FLF-40 is actually under-rated for our application, but it would be safer to choose a more conservative
approach to wiring protection, so stick with the FLF-40.