Wierd electrical issue

[87scottsdale]

Ok it's dark here so I didn't have time to do everything I need to do to try and find this gremlin,but somewhere along the line someone could have had this same problem.

All lights work as they should, Dome,headlights,running lights brake lights,cig lighter etc,etc.

Problem is my radio will not power off with the ignition off. I have thought a sticky/bad ignition switch,but got to check that and it is not the culprit.

So I get to checking fuses. Nothing blown or out of the ordinary. Pull the radio fuse. Radio still on. So then I get kind of frustrated. Start pulling all fuses and see which one is feeding 12v to the switched power on the radio.

Pull the T/L CTSY fuse and bam radio goes right off. Could this be a bad body ground somewhere or a dead short at a fusible link before or even possibly after the power block on the firewall?

Going to mess with it some more tomorrow,but maybe some suggestions or a better starting point?

[87scottsdale]

Also just to add. Aftermarket stereo. Has been installed for 2 years and no problems. This just started recently.

[Captkaos]

There are wires in the aftermarket wiring of the radio that are jumping power somewhere.

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

[87scottsdale]

There are wires in the aftermarket wiring of the radio that are jumping power somewhere.

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

You think in the head unit its self? Once this issue arose I completely redid each connection from the main harness to the radio. and even created a secondary ground as I thought that was my issue.

[winky]

if you have a test light with the key in "off" position  test the red wire coming from the radio and see if it has power, next check the yellow wire. the red should not have anything. the yellow should have low voltage because it is a memory wire. if your red wire does have power pull the radio fuse as you stated before, if that still doesnt kill the power you will need to start tracing that wire back and see where the hickup is

[87scottsdale]

if you have a test light with the key in "off" position  test the red wire coming from the radio and see if it has power, next check the yellow wire. the red should not have anything. the yellow should have low voltage because it is a memory wire. if your red wire does have power pull the radio fuse as you stated before, if that still doesnt kill the power you will need to start tracing that wire back and see where the hickup is

Already pulled just the radio fuse. It did nothing. Only thing that cut power to the radio was the T/L CTSY fuse. Then with that pulled no dash lights,running lights.

Key was in the off position and keys removed during this time pulling fuses.

[bd]

Using a test light, ignition off, and radio harness connected to radio, which wires are 12 volts hot - probe the ground wire, as well?  Check again with the T/L CTSY fuse removed.  Post the results.

[Irish_Alley]

does your radio have a dimmer feature for night driving? could this be wired into the trucks headlight switch so when your headlights are on it dims and that wire is somehow powering your stereo?

[87scottsdale]

does your radio have a dimmer feature for night driving? could this be wired into the trucks headlight switch so when your headlights are on it dims and that wire is somehow powering your stereo?

I think it could,but if it does it's not active. Possible though.

Using a test light, ignition off, and radio harness connected to radio, which wires are 12 volts hot - probe the ground wire, as well?  Check again with the T/L CTSY fuse removed.  Post the results.

I did mess around a couple more minutes. Swapped power and memory wires. Radio functions as normal except no memory. Also just to test I unhooked the ground wire to the radio and no change. Also checked for a short in the headlight switch by disconnecting it and No change. Will have to find my test light and volt meter in the morning and do some probing.

[bd]

Just to make sure we are on the same page, your radio should have accessory power (some installers substitute ignition power) to turn it on, and constant battery power to maintain memory.  The "tests" I described should be sufficient to determine whether the fault is internal to the radio.

[87scottsdale]

Just to make sure we are on the same page, your radio should have accessory power (some installers substitute ignition power) to turn it on, and constant battery power to maintain memory.  The "tests" I described should be sufficient to determine whether the fault is internal to the radio.

Will find my tools later on this morning. I'll will post back with what I find.

[87scottsdale]

I do believe its the radio gentlemen.

Harness unhooked from stereo only Hot wire is Memory as it should be. Radio plugged in with ground disconnected no power. Ground arcs when attached.

Either an internal short in the radio or something is feeding 12v to the entire chassis,but everything works as intended.

Also Just tested ACC on radio unplugged and 12v switched on the radio harness works as intended.

[87scottsdale]

Radio also grounds through the antenna. With no harness ground connected. I have the internal (in the windshield) antenna. That should NOT be grounded correct?

[87scottsdale]

Brother is dropping me off another radio and I will test power,ground,memory with that too make sure it is the radio.

I back probed each connection with the key on/off and everything is intended.

[87scottsdale]

It was the radio.

Brother dropped another off. Quickly just wired power,ground memory. Everything back to normal. Thanks for the replies and help!!