95 4runner Radio works in aux, but not on

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=138673
Printed Date: May 10, 2025 at 7:49 AM

Topic: 95 4runner Radio works in aux, but not on

Posted By: ponchosmule
Subject: 95 4runner Radio works in aux, but not on
Date Posted: March 16, 2015 at 1:12 PM

I have a 95 4runner with an aftermarket Walmart head unit. When I turn my key to auxiliary the radio will come on. When I turn the truck on the radio shuts off like it loses power. The power button does nothing.

Replies:

Posted By: racerjames76
Date Posted: March 17, 2015 at 7:55 AM

I was not aware walmart made radios. Obviously I am being a jerk and obviously you did not list the manufacturer of the radio. Even the cheapo radios have a part number somewhere on the faceplate.

It almost sounds like a ground issue...you would need to pop the radio out and use a volt meter to verify the 3 main wires. If the harness is using standard American wire colors (some cheap radios do not....be careful), you need to verify:

Black wire is grounded in all key positions

Red wire has 12v (roughly battery voltage)(no less than 11v and no more than 15v) in only accessory and run positions

Yellow wire (if the radio has a clock)(again some cheap radios do not have this) should have 12v battery voltage at all times.

If you need further assistance let us know!

-------------
To master and control electricity is perfection. *evil laugh*

Posted By: ponchosmule
Date Posted: March 17, 2015 at 9:27 PM

racerjames76 wrote:

I was not aware walmart made radios. Obviously I am being a jerk and obviously you did not list the manufacturer of the radio. Even the cheapo radios have a part number somewhere on the faceplate.

It almost sounds like a ground issue...you would need to pop the radio out and use a volt meter to verify the 3 main wires. If the harness is using standard American wire colors (some cheap radios do not....be careful), you need to verify:

Black wire is grounded in all key positions

Red wire has 12v (roughly battery voltage)(no less than 11v and no more than 15v) in only accessory and run positions

Yellow wire (if the radio has a clock)(again some cheap radios do not have this) should have 12v battery voltage at all times.

If you need further assistance let us know!

Sorry I was at work when I posted this. I will see if I can spot a brand name in the morning. This is not my DD and the weather was crap today. I will check brand and follow up. Thank you for the help thus far.

Posted By: ponchosmule
Date Posted: March 24, 2015 at 6:14 PM

Ok I took everything apart today.the strange thing is I unplug the harness from the back of the head unit to check voltage. Everything checks out. Plug it back in and it works just fine. Starting to think this head unit may crap out after it heats up?? posted_image

Posted By: i am an idiot
Date Posted: March 24, 2015 at 9:55 PM

It will not crap out after it heats up. It will probably crap out before it heats up.