GPS install puzzler

I am mounting my Garmin Zumo 450 to my 2004 R 1100 S

I mounted it and it didn't work, this will be the fourth bike this mount has been one.
I tested and I had power up to the mount, so I figured something had gone wrong with the mount, so I ordered a new one.

New mount gets here, still no workie.

So I ordered a new power cable. Before I mounted it to the bike I tested it with the battery I have in my garage that is for my trailer. Works great. Get it on the bike and no workie again.

No, it can't be a CAN bus issue, I am powering it directly from the battery.
Again this is the fourth bike I have hooked up this way, first three were 1994 R 1100 RS, 2004 K 1200 RS, 2002 Ducati ST4s

I checked voltages, on the bike I have 13.47 volts at the mount.
On my bench I have 13.35 Volts


Any Ideas??

TIA,
Karl

How solid is the ground with the mount to the bike?
NCS

It's not clear to me if you can get the GPS to work on the bench in the cradle, or in a car in a second cradle?

There is only the battery, cable, cradle, or GPS that can be checked. It sounds like you get power to the cradle...

Can you give more details?

I now have two cradles because I ordered one to replace what I thought was a defective cradle. Same with the power cords

GPS will work in both cradles when on the work bench, but not on the bike.

Will also work in my car cradle.

Here is a web page from the install on my K 1200 RS, it is hooked up the same way.

http://www.karlsgarage.com/motorcyclepage/GPS/gpsadd.htm

After looking at your install, I wondered if you checked the fuse? Flexed the cable on the bench to see if there is problem with it?

And, rechecked that ground?

Really can't be too much with such a direct connection. Frustrating, for sure.

Polarity.

I have never worked on this bike before.

Battery is under the tank, which I did not remove because I had access to the terminals with it on.

I ASSumed that the terminal with the plastic cover on it was the positive terminal. But no.

Ah yes. You're the ONLY person on the planet to make that mistake....

Rule number one when working on electrical devices - ALWAYS test with a VOM before moving forward.

Simple mistake, simple solution - last thing we thing of when we're running into problems. BTDT....