GPS Power - hardwired into taillight...intermittent power loss though?

[positivecarry]

Hey guys, I recently hardwired my GPS by tapping into the power cables for the taillight (so it feeds power to GPS when the key is turned on, but not otherwise).

I am having a perplexing problem though: when I start riding after a couple days and am riding out of the city (NYC, so I'm never going faster than 30mph, usually much slower in traffic), the GPS keeps losing its power connection.  Once I get on the highway and get up to speed, the problem goes away.

Could this be something where the bike can't power accessories enough when the engine isn't turning over enough?  I am new to bike electronics, but I remember with cars that just idling around at low speeds wouldn't provide enough charge to power electricity-intensive accessories.  Is it something like that?

Or is it just my cable being poor quality?  The brake light continues to function through these power dips and I've soldered the splicing, so I'm pretty sure I have a good connection.

[Howie]

You need to recheck your wiring for the GPS.