Factory Stereo, electrical issue? Stereo issue?

[WigglesTheHoly]

So I have a factory am fm stereo in my 78 that I decided I needed rear speakers instead of the single dash speaker.I modified a front speaker connector off another truck as I do not have a factory rear speaker plug. I made new pins for the blank spots in the plug wired it up even heat wrapped the cables to make it look nice and not a hack job. I plug the speakers in fire up the truck turn up the stereo and...nada from the back. I was only getting sound from the front speaker. perplexed I checked the connections and everything looks fine. I pull the wires out of on the speakers and dropped it on accident the ground wire touched metal and boom my rear speaker that is still plugged in starts rocking.... so I plug the speaker back in and ground the ground wire on that speaker to the truck boom both start working...... Bad ground I thought. I shut the truck off and then turn it back on....Nothing out of the speakers. I de-ground the back speakers from the truck and boom sound from the front.. I tested it again same result...


what the heck is going on?

[motornut]

was the truck factory stereo or mono cause the front single is wired differently then the two or 4 speakers
the single has the wires on both sides of the plug
if it's stereo they are on the same side

[WigglesTheHoly]

i'll try and take pictures tomorrow. They were vertical i believe with an open vertical slot on the white plug

[WigglesTheHoly]

ok I understand now its factory mono
so if I unplug the front I should have my 2 in rear. Correct?

[motornut]

should be rockin!

[WigglesTheHoly]

Motornut your avatar is rocking lol.

[WigglesTheHoly]

Ok went out and tried it still nothing so I thought hmm lets see if I plug my rears into the front socket on the radio.... We are rocking now. So I wonder if the rear on my factory radio is burned out or if I have to have my front speakers wired in left and right before I can have rears? I don't know, but at this point I'm just happy to have Stereo instead of MONO.

[motornut]

Yup he's a rocker
na i've had front or back workin at different times sometimes alone
mighta fried something.....fader?

[motornut]

just to mention to that mine the copper piece broke for the power plug part (bypassed it)
and i was thinking these plugs only fit one way
maybe check the colour code
so i took some more pics

[WigglesTheHoly]

my power plug has 3 wires. the front speaker plug just has gray and brown. I didn't have a factory back speaker setup. But I'm pretty happy with just the rear speakers I just wanted a full sound, now I have it. I'll probably still mess with it but I have the ac duct back in and have it all thrown back together to drive back into work tomorrow. But Thanks for all the help when I get back to checking it out again I'll resurrect this thread.