Sure, that's no problem. Would you still use the Universal Mount to attach the TAPP Lite?
The SAE should be on a fused circuit -do you know what the fuse rating is? We use a 7.5A fuse but the TAPP Lite cable will handle up to 15A. The TAPP Lite itself is internally protected with a auto-resetting fuse so it is safe no matter what. The in-line fuse just protects the cable.
Also, what Garmin are you using. If it is a Nuvi then you will need our Garmin Charging Cable. It is the only cable available that will allow the Nuvi to charge and navigate. More info here:
Let us know how you want to attach and the pigtail length and we'll put something together for you.