1985 Bronco II XLS radio problems

[jaredm_k]

Hi everyone - I'm having trouble with my radio. I'm attaching a picture of the radio I have in my 85 bronco ii. Here is the story (just so you can get a complete picture):

The radio has never worked in this bronco since I bought it so I finally pulled it out to take a look. Behind it, the wiring had all been clipped from the factory plugs. So I wired it back up, unfortunately without the factory plugs, turned it on and I had a radio! I was still missing a speaker wire or two simply because I couldn't find all the wires that had been cut.....but I had sound and that was good enough for me. Here is the problem, after driving for somewhere between 20-30 minutes, I hear a slight pop and it goes quiet....like so quiet that I can't hear it with the vehicle running, but still something coming out of the speakers. The headunit stays on. Go into work, come back out and it is on again....works for 20-30 minutes on the way home and same thing happens. While I am thankful to have a radio for half of my commute, I would love to figure this out.

It seems like to me that there has to be a factory amp that is getting hot and shutting off. Since the head unit stays on and there is still a signal coming out of the speakers....but I'm not an expert by any stretch so I am hoping somebody smarter than I can help me troubleshoot a bit. Thanks for your time!

Jared
1985 bronco ii XLS

 

[JerryC]

May not be the answer you want...
For what radios cost, I would just get a new radio.
EX: I put this radio in my BII.
http://www.amazon.com/gp/product/B00I9KBLII/ref=oh_aui_search_detailpage?ie=UTF8&psc=1"]]http://www.amazon.com/gp/product/B00I9KBLII/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

$87, has cd, usb and bluetooth, with hands free phone.

When you are done it will look better, sound better and will be ready for better components when you add them.

 

[jaredm_k]

Thanks Jerry - I have a headunit I could throw in there....but I would prefer to keep it as a stock look. Also, if there is an amp that is bad somewhere, I would have to bypass it or I fear I would still have the same problem. Thanks again for the reply!

 

[JerryC]

On the 86+ they were prone to having the amp in the head unit burn up. burn up, but I don't know about the earlier ones. You can see if you have a direct line to the speakers by using a battery across the wires and seeing if the speaker moves. Or if you have a meter short them together at the radio end and look for continuity at the speaker side, Leave the key off.

Sometimes I see factory radios on ebay.

 

[jaredm_k]

Got it - I will try that as soon as my garage isn't 10 below zero! Ha. Thanks again for the info!

 

[ab_slack]

I would normally expect the factory radio to not have any sort of external amp.

Although with all the wire cutting there may be something added someplace.

Use a meter and resistance check each speaker set. Also as suggested above you should hear little pop or some sound if you hook the ohmmeter across the leads.

My gut feeling is you are correct, there is overheating going on and the final amplifier turns off. But that could be in the main unit not necessarily an external amp.

So the question is why is it getting hot? A few causes.

Maybe your heater is putting hot air out under the dash? A

Perhaps one of the drivers is going into a short circuit. So go from each speaker output pair of wires from the radio, disconnect from radio and check the resistance of the speaker. It should be like 8 ohms though some systems have lower ohm speakers or speakers in parallel making it 4 ohms.

Is it possible someone added speakers? Changed out the speakers for a different type? Or connected existing speakers in parallel? Any of these may be presenting a lower speaker resistance thus overloading the radio. I don't know if you should see 4 ohms thru the speakers or 8 ohms. If you see 8 you are safe. If you see 4 you should check to see if it is supposed to be 4 or 8. If you see significantly less than 4 Ohm like less than 3 ohm that channel is probably overloading the radio.

 

[efilnicufecin]

Do you have any speakers that do not work?....If you do, disconnect them from the stereo, and see if that fixes the problem....if it does. you have a shorted speaker circuit.
repair the circuit(s) and everything should be fine.