Newb head unit install question

littlehoov · 02-06-2010, 01:47 AM

Ive installed 3 or 4 head units in my life, but ive never had to deal with adding an antenna.

I recently bought one of these:

Scosche WMA Car Window Mount Antenna - AMPLIFIED! NEW!! - eBay (item 300391925114 end time Feb-28-10 16:20:04 PST)

Im replacing the antenna on my XJ because its gone, and the factory radio didnt work either so im installing a new head unit.

My question is, the antenna requires a power source, so should I use the blue power antenna wire coming out of the head unit to power it? Or should I just tap into the switched 12v going to the head unit? Or does it make any difference either way?

JeffsJeepWeb · 02-06-2010, 02:06 AM

to be safe, I'd read the documentation that comes with the head unit and the antenna to determine if the deck provides enough amperage to run the antenna. You run the risk of damaging both if it doesn't. A lot of those blue leads are simply to provide enough power to trigger a relay. That said, it probably wouldn't hurt to run a fused link from an accessory circuit to power the antenna.

**SirGCal** · 02-06-2010, 08:13 AM

It depends on the amount of power it's going to draw. The antenna output on new radios have almost no power output. They are a signal wire, not a power wire. At worst, you'd use that wire to power a relay to give the antenna power when the radio is on. That relay itself could be powered from even the battery and that would be fine since it will only work when the radio is turned on. Where you can get your power from and whatnot though all depends on what it's going to pull.

littlehoov · 02-06-2010, 11:55 PM

Alright thanks guys, I figured it was mostly a signal wire, so in that case Ill probably just run both the head unit and the antenna off the switched 12v wire. I dont have the antenna yet, and may not for a while from the looks of the weather forecast.

littlehoov · 02-08-2010, 01:30 PM

I have another question, how in the world do all you XJ owners cram all the wiring inside that tiny little dash opening?!

Are there any tips and tricks to doing it? I still dont have the antenna, but theres already a lot of wiring to try and cram in there.

**SirGCal** · 02-08-2010, 04:58 PM

Cut em shorter is a simple way I do a lot. I don't keep the entire adapter's length if I'm using one. Maybe half... or a third...

02-06-2010, 02:06 AM	#2
JeffsJeepWeb Registered User Join Date: Feb 2010 Location: Seattle Posts: 19 Profile Gallery Classifieds My Jeeps	to be safe, I'd read the documentation that comes with the head unit and the antenna to determine if the deck provides enough amperage to run the antenna. You run the risk of damaging both if it doesn't. A lot of those blue leads are simply to provide enough power to trigger a relay. That said, it probably wouldn't hurt to run a fused link from an accessory circuit to power the antenna.