Hands Free Kit - simple ques!

Printed From: the12volt.com
Forum Name: Cellular and Communications
Forum Discription: Cell Phones, Hands Free Kits, Bluetooth, Two Way Radios, CBs, Pagers, Wireless Internet, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=18192
Printed Date: May 14, 2025 at 11:54 AM

Topic: Hands Free Kit - simple ques!

Posted By: stokes69
Subject: Hands Free Kit - simple ques!
Date Posted: August 28, 2003 at 9:32 AM

just purchased the motorola hands free car kit for the t720 handset. i plan to install the kit in my 1992 ford explorer xlt (4dr) this weekend. the installation guide says:

"connect the green ignition sense wire (2 amp fuse) to a source that will remain high (not switched off) while the vehicle is cranking, but will go low when the ignition is turned off. (this source must be found through testing due to the many different models of vehicles.)

question: do i connect the "green ignition sense wire" to the (+) 12 volt ignition wire (also referred to as the "switched" power wire?)

i plan on connecting the mute feature to my sony cdx-mp70 hu.

"connect the orange entertainment mute wire. this is only operational if the car radio supprots this capability. installation may require an optional relay (not included).

question: do i connect the "orange entertainment mute wire" directly to the mute wire on the head unit?

all help would be greatly appreciated!!!!!!

Replies:

Posted By: meangreentahoe
Date Posted: August 28, 2003 at 9:56 AM

I would personally just use the switched lead off the back of your radio... but thats just me

On the whole mute wire thing, you would have to find out what kind of signal the hands free set puts out (positive or negative) and then find out if your headunit requires a positive or negative input. If the output of the hands free and the input for the radio are the same, no relay is required. If different, you need to use a reverse polarity relay configuration. I will try to find out the specs on your deck and handsfree at work today and will let you know what i find out tonight

Posted By: stokes69
Date Posted: August 28, 2003 at 11:08 AM

Thanks - very much appreciated. So, I can just connect the GREEN Ignition Sense wire to the switch lead on the back of the radio?

Posted By: stokes69
Date Posted: August 29, 2003 at 8:55 AM

Okay - I was a little eager - and wired most of it up last night. The handsfree kit activates after I start the car and the ignition returns to the on position. So when the car is cranking - it does not turn on - not until the ignition tumbler returns to the on position. When I shut the car off - the handsfree unit shuts down. It also does not charge the handset when the car is off - I AM GUESSING THIS IS CORRECT- if not please let me know what I am doing wrong.

I also attached the Orange Entertainment Mute Wire from the handsfree unit to the "ATT" wire on the back of my Sony CDX-MP70 HU. Nothing happened when a call was received or placed. How can I get that to work??

Thanks again!