OEM Radio Not Producing Sound


projectRanger93

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My Stock '93 unit powers on, has antenna reception, and the tape cassette seems to work, but I'm not hearing anything out of any of the four speakers. I don't have the Premium Sound version, and I searched online for potential problems and I found that the radio will not put out sound if one of the speakers is grounded out. My plan is to take out the unit, put a small battery voltage through the harness pins for each speaker and determine if they make noise or not.

Is my approach correct or do you guys suggest something else?

Here's the pin out of the connector harness if that adds anything to the pot.
29486
29487
 


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RonD

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Yes, that will work

More than likely the amp is bad, but yes most amplifiers have a "protect circuit" so if speaker wire drops below 3 OHMs amp will shut down.

You can just use an OHM meter on each speakers wires, should read 6-9 OHMs, then OHM each wire to cab ground to see of its 0 OHMs, shorted
 

projectRanger93

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Yes, that will work

More than likely the amp is bad, but yes most amplifiers have a "protect circuit" so if speaker wire drops below 3 OHMs amp will shut down.

You can just use an OHM meter on each speakers wires, should read 6-9 OHMs, then OHM each wire to cab ground to see of its 0 OHMs, shorted
Sweet thanks for the suggestions. I will try that out tonight. You mean the internal amp to the radio unit? Since this isn't the "premium sound" version there isn't an external amp behind the glove box. If internal, is it a part that I can replace?
 

RonD

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Yes, the internal amp.

Probably not but never looked inside one?

But you would need a working radio of the same model to get another amp out of and if you had that................well just install the working radio
 
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projectRanger93

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Fair. Alright I'll see what results the troubleshooting produces. Thanks for the tips.
 

projectRanger93

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So I measured the resistances of each speaker and they were all about 6 ohms. I then measured between each pin and ground and none came up as 0 ohms. Hmmm... then I guess it's internal to the unit. I'll have to open it up and see.
 

projectRanger93

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Anyone know of where i can find an internal schematic of the stock radio? Or what else i can check?
 

Ranger850

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Why don't you just replace the stock unit, either with another stock deck, or an aftermarket one? Seems like you're going through a lot of trouble to fix a part that could be easily replaced.
 

projectRanger93

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Because I could either replace an internal electrical component that costs a few cents or dish out the $$ to get another head unit. Junkyards in my area rarely have rangers and if they do they've already been gutted. I'm not for aftermarket products as I'm keeping this truck as stock as I can.
 

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I doubt there will be "Ford" schematics, check if there is a OEM manufacturers label or model ID, then check if you can find info from them

Board level repairs were not done on most car radios unless there was some "classic car" connection

ebay is a good source for parts, Google: ford ranger factory radio ebay
 

projectRanger93

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So I opened the radio up and I didnt see anything visually wrong. I tested the amplifier chips and they seemed to check out. I didnt bother troubleshooting the rest so I found a cheap replacement on Ebay and it worked. 👌
 

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Good work (y)

Thanks for posting the update
 

PetroleumJunkie412

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i really thought this was going to be another CHOWDAH incident...
 

Ranger850

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Why don't you just replace the stock unit, either with another stock deck, or an aftermarket one? Seems like you're going through a lot of trouble to fix a part that could be easily replaced.
So I opened the radio up and I didnt see anything visually wrong. I tested the amplifier chips and they seemed to check out. I didnt bother troubleshooting the rest so I found a cheap replacement on Ebay and it worked. 👌
you're welcome ....🤘
 


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