Old Pioneer head unit and line out converter question

[jlatenight]

I have an ancient Pioneer head unit that only has 3 speaker wires. It's an old Jeep requiring a shaft-mount stereo (mounted by the knob shafts), and I don't want to cut the dash for a DIN. There's +L and +R, but only one negative wire out of it. You're supposed to wire the negative to one speaker, then jump that terminal to the other speaker's negative. Obviously the LOC has 4 wires. I tried twisting the two negatives together on the LOC to the single ground on the stereo, but there was only sound from one speaker. I have a feeling I might be screwed. Anyone know how to deal with this?

 

[jlatenight]

No one? Li'l help?

 

[jlatenight]

No one? Li'l help?

 

[jlatenight]

In case anyone needs this info in the future, I needed a Floating ground adapter I use it backwards so my stereo connects to the output end of the adapter w/ the 5 wires, and the adapter input to the LOC is self-explanatory.

 

[jlatenight]

Welp, I wired-up the Floating ground adapter, but it didn't work. I was told to use it backwards than typically used. It's usually for a modern stereo to be installed into an old vehicle with speakers grounded to the body. I have the reverse problem. Only one neg speaker wire coming out of the stereo. Can anyone help me? I would be forever grateful!

 

[jlatenight]

I feel like there has to be a way to do this. I have the dash ripped apart and I'm wondering if I should just say f-it and make a DIN.

 

[dragon.breath]

Their are options. It depends on how much you want to spend. Some of the ‘floating screen’ head units could be adapted for an old car without cutting the dash. My Joying head unit uses a ribbon cable to connect the screen to the main unit. I believe that they sell extended ribbon cables that would allow you to mount the unit behind the dash. Then put the screen where the stereo sits. Of their are companies that offer 2 shaft stereos for classic cars.
https://customautosoundmfg.com/

 

[jlatenight]

Much appreciated. Maybe this will help? I'm looking for an easy cheap solution to this. I just need to make a single speaker ground out of the radio to 2 separate grounds (negs) on the LOC.

 

[Firewalker]

So look around on eBay for a unit like yours but with RCA outputs on it. Some of those shaft older radios like that in the '90s had RCA outputs on them. I know I had a Sony as a cheap option once and it had a pair of RCA outputs on it for adding in an amplifier like you want to do. That way you don't need the LOC.

 

[dragon.breath]

Honestly, here is what I would try. Those old 2 channel radios didn’t put out a lot of power. Forget the LOC. Connect the wires from the radio directly into rca cables, and then run a ground loop isolator.

 

[jlatenight]

look around on eBay

yeah def an option

wires from the radio directly into rca cables

hmm, my Pioneer only puts out 3.2 Watts/channel. So connect the male RCA cables' negs together and then to the single neg on the radio?

 

[dragon.breath]

Yup. 3.2 watts at 4 ohm is less than 4 volts.

 

[Deiimos]

In the event it doesn't work, I would try posting over at https://www.diyaudio.com/community/forums/car-audio.38/ in the car audio section to see if anyone can help. May or may not, but doesn't cost anything to ask.

 

[jlatenight]

Yup. 3.2 watts is less than 4 volts.

It worked! I have it hooked up to the amp and it seems to be working well. Thanks so much for the help.
I do have one issue with this ancient Pioneer HU. the left side is louder than the right. The balance control obviously helps, but there's def something wrong with the HU itself. I was hoping there was a pot or other control inside it I could adjust. Is there such a thing?

 

[dragon.breath]

I have never had one apart. It’s possible.