1615TM Power cord mess up

[Friggin New Guy]

I have too many devices in my car not enough outlets so I decided to run a direct connection from the fuse block to the TomTom. I purchased a 12v-5v block and ran a fuse tap from the block. I thought I verified the power lines from the TomTom cable having read that there was a sensor line and a 5v ground. I matched the lines and thought it was working well until last night when I fine that the TomTom is not charging. I went back and verified that the block is giving me 5v and then looked at the sensor line only to find that a the splice point that I left hanging is actually another coax wire with ground and power leads, I think, and I have no idea what I'm going to do with those. Do they also connect to my 5v block or direct to 12v or ???????. Any help would be appreciated.
Thanks Friggin New Guy

 

[canderson]

Your reference to the old 3 wire cables is not relevant to these newer units. Rather than a proprietary cable, they use ordinary USB cables.

USB cables, often those even for 'power only', will include 4 wires. Nothing too unusual about that. Your cable is likely a standard USB cable, with two wires for data and two for power. Remember, that port is for charging AND data (when it's connected to something intelligent). To reduce EMI, both pairs are typically shielded.

Tell us what the colors are for your two pairs. I would expect a red/black pair in one shield, and a green/white pair in the other.

Would also be curious for a link to your 12V>5V 'block'. Sounds interesting.

 

[Friggin New Guy]

Both sides of the cable are coax red and ground on one side black and ground on the other. after a lot of research I found that it the Black ground was actually is the FM antenna for traffic and below the plastic is where it turns to just a white coax. So I was able to figure it all out, after running several voltage tests and using an obsolete micro usb to confirm my finding, got it right and re-soldered all my connections back again. the 12v-5vdc block is available from Amazon SMAKN DC/DC cconverter 12V Step Down to 5v/3a Power Supply Module .
Than ks for the input and help
FNG

 

[canderson]

Ah -- you've got a cable with the RDS dongle on it, not just a regular power cable. That explains a few things!
Wish I'd paid more attention to the fact that you have a TM unit -- the "T" should have tipped me off.

Glad you got that sorted. Looked into your DC/DC module. Small, light and 96%+ efficient. Nice! Certainly won't generate much heat with that.

Out of curiosity, does your unit serial number start with characters "EU" or "ET"? Since you're in the US, I'd figure it should be "ET". They call this model the Start 62 over in Europe.