Aftermarket Radio help?

[Jay P]

I recently installed a new Kenwood headunit into my 1988 GMC Pickup. Made sure all the wires where matched to the correct colors. The stereo doesnt work neither does the HVAC. The underdash lights dont work (my dome light never worked in the first place). The headlights still work. The truck still starts. Everything works except the stereo and the HVAC. When the truck is off the stereo will work but when you turn the volume past 30 or open the door (interior light comes on) the radio will turn off. Also when the truck is running the radio cuts off. I checked the CTSY 20A fuse and it doesnt seem to be blown. Any suggestions?

 

[Jay P]

I recently installed a new Kenwood headunit into my 1988 GMC Pickup. Made sure all the wires where matched to the correct colors. The stereo doesnt work neither does the HVAC. The underdash lights dont work (my dome light never worked in the first place). The headlights still work. The truck still starts. Everything works except the stereo and the HVAC. When the truck is off the stereo will work but when you turn the volume past 30 or open the door (interior light comes on) the radio will turn off. Also when the truck is running the radio cuts off. I checked the CTSY 20A fuse and it doesnt seem to be blown. Any suggestions?

Correction, the underdash are very dim.
Also when I remove the CTSY fuse the underdash lights go back to being bright but my HVAC and Stereo still dont work

 

[kennythewelder]

You have some wires crossed somewhere. If you used a wiring kit, then maybe you got the wrong kit. The only way to find out what is going on is by testing with a test light or an OHM meter. Be sure by testing that your are getting power where you should be, and that you have a good ground.

 

[Jay P]

You have some wires crossed somewhere. If you used a wiring kit, then maybe you got the wrong kit. The only way to find out what is going on is by testing with a test light or an OHM meter. Be sure by testing that your are getting power where you should be, and that you have a good ground.

I made sure I got the right wiring kit and when saudering the harness I made sure I matched the proper colors. The only colors I didnt use was the orange wires for the dimmer because my radio didnt have the dimmer wires. However a while back before installing my aftermarket stereo I unplugged my stock stereo under the dash and ran into the same exact problem but it fixed when I plugged it back in.

 

[Gambles]

I'd start with a good ground, could possibly be back feeding. I'm probably going to rewire my radio all together, for some reason when I cut the headlights off or on there's a split second drop in power or ground or something. I'm not sure, only does it occasionally but just long enough to reboot my radio... I'm not against the fact it could be just something funky with our stock wiring. I only get constant, switch 12 and illumination of my stock plug so it's kinda hard to mess those up. Although I have seen some messy wires shorting each other out before on some other people's installs, one guy actually had a wire laying down on his stock hvac controller shorting it out because it was bare laying across the top of the circuit board.

 

[Jay P]

I'd start with a good ground, could possibly be back feeding. I'm probably going to rewire my radio all together, for some reason when I cut the headlights off or on there's a split second drop in power or ground or something. I'm not sure, only does it occasionally but just long enough to reboot my radio... I'm not against the fact it could be just something funky with our stock wiring. I only get constant, switch 12 and illumination of my stock plug so it's kinda hard to mess those up. Although I have seen some messy wires shorting each other out before on some other people's installs, one guy actually had a wire laying down on his stock hvac controller shorting it out because it was bare laying across the top of the circuit board.

As far as my wiring goes I did sauder and heatshrink all of the wires and with the ground I matched both black wires together on the head unit and wiring kit on the truck, wouldnt hurt to double check though

 

[Gambles]

Eh personally, I would skip the factory ground solder you a lead on run it down to the framing of the dash, or even the body in the kick panel or something. And good if you color matched everything your next step would be compare the schematic with your wiring kit with a fluke meter to what's getting put out by the factory wires, I can get you a wire end view of connector with a pin out for what they do when I get to a pc in the morning.

 

[Jay P]

Eh personally, I would skip the factory ground solder you a lead on run it down to the framing of the dash, or even the body in the kick panel or something. And good if you color matched everything your next step would be compare the schematic with your wiring kit with a fluke meter to what's getting put out by the factory wires, I can get you a wire end view of connector with a pin out for what they do when I get to a pc in the morning.

I will check and most likely try and ground it too the dash frame and probably double check or re do the yellow ignition wire and constant red wire. When wiring I did check the wiring from the harness and radio to make sure I was wiring them properly. Also if I was to re do the wires would it fix my HVAC. Previously when running the stock radio when I simply unplugged it under the dash I would run into the same problem

 

[Gambles]

Wait what did you unplug under the dash to kill the Hvac?

 

[Jay P]

Wait what did you unplug under the dash to kill the Hvac?

All I unplugged was the connections at the bottom of the radio unit.