Radio Problems!?

[FredCookJr]

Hi, Im new to this website & im only 16. I dont know much about cars, im still taking engine shop & were only learning basic's like oil change, tire rotation's, & stuff like that. I wont learn my Computer/Electromechanical basics until my junior year. Ive had my 70' Monte Carlo since 8th grade. But back to my issue, when my dad got it, it had radio issues like it would come on & off every now & again. But ever since someone hit the back end of it, the radio wont work at all (extra info: the accident was just a fender bender.) & i dont know where to start to try fixing it. please some one help me? if it makes a diffrence, i am a premium member. If you need pictures or anything please let me know, im desperate

[Leghome]

It could be the antenna wire got knocked loose. It plugs into the back of the radio. Is the antenna in the windshield? My 70 had that antenna and it was a problem at times. My present 72 Monte has a power antenna on top of the left quarter.

[FredCookJr]

it does have the antenna in the windshield, ill go check to see if thats the issue. thank you for replying! ive only been on the website for a day & i already love the friendly users.

[Leghome]

That is why we are here to help one another. I also replied to your PM

[FredCookJr]

i just went out & looked at the monte & honestly, i didnt know where to start. i dont know what cable the antenna is, i tryed adjusting the antenna. but is there anyway to tell if its the speakers or the actual radio? the guy before us had "better" speakers put in it. so basically, there not the original speakers. i dont know what to do. this sucks )':

[monte70car]

You say the radio turns on and off(mainly off) at anytime which to me sounds like a lose ground wire or maybe a lose hot wire. There is no way to adjust the antenna that is embedded in the front glass. Depending on if the radio can be taken out it would be hard to see the antenna unless you take the dash pad off and remove the a/c heater control panel. The antenna will be a thick black cable which is mounted to the window shield frame under the dash pad.

[Big Jim]

If you were hit in the rear and have no dash speakers then it might be a loose speaker wire in the trunk. You would be surprised how some people make speaker wire connections.

[FredCookJr]

@monte70car; i wanna take it to this electronical expert in my neiborhood but i dont have the money. but the antenna can be adjusted, if you take off the knob that allows you to change the station(the one on the right), after you take it off & look in there with a flash light, you'll see "ADJ ANT" & below that there will be a phillips head top. you use a phillips screw driver to adjust it.

@Big Jim; thank you for the suggestion, i think it might be that too because the person that owned it before us(some young fella) he had 21" rims on it & replaced the speakers with these "better" speakers. i was going to go take a picture of the wires & post them on here so that maybe someone could help me re-wire it? but anyway, thank you for the response.

[Big Jim]

The antenna trimmer in the radio should not need adjustment. I would leave that to the pro's but radio grounds and speaker wires I would check.

[Mo's70MCs]

Simple to fix! Very hard to teach in a forum. How much time do you have? Start from the basics..and by that I mean basics. What do you suspect not working. Minimum you'll need a circuit tester (test light) ok, need a working speaker, power source, see where I'm going. A bench check would be ideal, yet I doubt you'd want to pull the unit out of the dash. So you'll have to do some slight investigation. Make sure none of your connections are broken or loose, that you have good grounds. Mostly that you understand the way it works. It is so much easier to pull the radio and bench test it. I'm assuming you're working with a factory unit?

[72-CLASSIC_RIDE]

Here are a couple questions that may help us in determining your radio issues.

1) Is it a factory Delco Radio?

AM Band only - 1 Center Dash Speaker

or - 2 Front Dash Speakers

AM/FM Mono - 2 Front Dash Speakers

or - 2 Front & 1 Rear

AM/FM Stereo - 2 Front & 2 Rear Speakers

 

2) When Radio stops emitting sound, does it also loose power?

Or does the Radio emit static noise?

 

3) If other than AM Band, can you switch between AM/FM Bands and

get same result?

 

4) Does Radio initially power up and during usage does it quit

playing or does radio loose power?

 

5) Are speaker(s) factory 10 ohm or are they after market?

Only 10 ohm speakers are compatible with factory Delco radio!

8 ohm will work but 10 ohm recommended. Anything less could

cause damage to radio.

 

If a total lose of power, check your connections at radio. If power but no sound, check speaker(s) connection(s). Even if antenna is inoperable, you should still get static at minimum from speakers. If no noise emits from speaker(s) with volume turned up, you have no power at minimum going into speaker(s).

 

Here is a pic of factory radio. This is AM/FM Stereo but is consistent with both AM AM/FM looks.

 

AM only will not have slide bar near top center to move from AM to FM.

 

Here is a pic of rear.

 

On the far right is the power hook up. At mid point is the power capacitor(s). One if AM AM/FM Mono or 2 if stereo. On far left near bottom is receiver where antenna cable is plugged into.

 

The ground is part of the power connector and a stick on label right under connection will tell you which wire does what (if label is still ledgible or in tact).

 

If this helps in you narrowing down the source of your problem and isolating it, then you will be able to focus on it.

 

Try unplugging antenna from rear, cleaning contact & recepticle, ensuring a firm fit on cable plug in. Unplug connector, inspect, clean as needed (connector & recepticle) and reconnect it. Determine if power is going to speaker(s) by turning up volume. If radio always seems to power up when cold and then looses sound after operating for awhile, probably the power capacitor is weak. This is the round feature mid point on rear of radio. If no power at all in radio, likely a connection problem at radio or fuse block. Having a test light would be helpful in determing power issue. If power to radio is evident and speaker(s) emit noise, probably internal & radio will require removal and inspection by qualified technician.

 

That is how I would trouble shoot it if a factory radio.

 

Best of luck and welcome to the FGMCC.

 

Doug

[FredCookJr]

@Mo's70MC; i did attempted to pull the radio out of the dash but i couldnt get it, one of the screws under the dash is stripped. & another thing, i dont know ANYTHING about circuits or any of that. i wont learn electronics until my junior year(im still a freshman). i have bought a kit for electronics a while ago & it has a tester in it, i dont know what kind of tester though. but when i turn the radion on, i cant hear anything throught the speakers, not even fuzz! its horrible because i wanna prove to my dad i can fix it but we wont even give me a chance. but yes, i am working with the original radio. EVERYTHING is original except the speakers.

[Leghome]

Fred does the light on the radio come on when the light are on? That could show you are getting power to the radio. Either there is no power or a loose speaker wire connection are the two most likely options.

[FredCookJr]

@72-CLASSIC_RIDE

1) it has 2 rear speakers(non-original) i dont know about front speakers.

 

2) it used to play music on & off. i.e. if you made a sharp turn, it would turn off but if you just drove calmly, it would stay on but now it doesnt play at all, not even static or fuzz.

 

3) when i switch from am to fm, there is still no sound, not even static or fuzz.

 

4) it doesnt come on at all.

 

5) yeah, there after market speakers but the guy i bought it from gave us the original speakers too but im not sure if they still work or not.

 

& omg! thats the same EXACT stereo that's in my 70 monte, i unplugged the cord down in the far left today & i just blew in it & plugged it back up but it didnt make any noise, not even static. i think its the after market radio but im only 16, i have no idea.

 

 

im gonna upload a video of my whole radio/stero in the morning so maybe someone could help me figure out the issue. honestly, thank you for your time, it means A LOT.

[FredCookJr]

yeah, when im driving at night time, the gauge's & a/c & air condition, & radio all light up but no sound ):

[72-CLASSIC_RIDE]

Okay, if the radio face light is on then you have power to radio. If your not hearing any noise coming through speaker(s) with volume turned up and station tuned in, then it would appear the problem is between the radio connection and speaker connection(s). If radio was working and a sharp cornering intermittently made sound blank out, I would assume the problem is likely with the wiring. With radio on and tuned into a station, move wiring around with your fingers at / near speaker(s) and see if you get any noise through speaker(s). If you find by doing this noise is evident, isolate that wire and disconnect, inspect, clean contacts both ends and reattach wire ensuring a good solid contact.

Not being there, it is difficult to identify your problem! Because you had indicated speakers are not original, can't validate speakers are compatible with radio. Remember for a factory Delco radio, the speaker(s) should be 10 ohm to safely operate radio. For example, 4 ohm speakers could damage radio!

Knowing that you have power to the radio eliminates that portion of the problem. Focus on the speaker(s) now. Check contacts for any loose / open connections. If you are confident there are none, you will need to try a different compatible speaker. If still nothing, I would suggest problem is within radio internals and requires service. However, based on your description, I think you have a open connection at / near speaker(s) that is a poor contact or open ground! Even hitting a rut in the road could make speakers quit if poor contact / ground.

 

Can't offer any more than that and hopefully helps you to some degree in isolating your problem

Again, best of luck in finding and repairing it.

 

Doug

[VE3HZZ]

I am not sure why I am posting this to check...but give it a shot. The radio face from the dash lights does come on but nothing else. SO my suggestion FIRST to check (again read back and didn't see you mention it or didn't see it so under the dash LEFT corner against the firewall beside the emergency brake is the fuse block. All glass fuses. There is one specific for the radio. Check IT and see if someone at some point hooked in some power point (blade connector) to this or somewhere else from the battery and it is LOOSE.

 

Take that fuse out and see if it looks GOOD and use a multimeter if you have one and check that there is continuity through it (google that if your not sure the term) and confirm that it is GOOD? Radio is marked as such in white on the block. Tangs on glass fuse style can become loose especially if someone didn't remove them right (don't pry it on the glass part of you'll break it)

 

If the radio is getting power and when you turn the switch ON even get a crackle for a moment there sees to be power. If power and no sound at all and speaker leads are known to be good and test speaker even (can connect one to test) does nothing it can be the final amplifier section of the radio which is on the other side of the finned aluminum block you see in that rear picture.

 

Also some of these radios could have an internal fuse inside that if blown will do the same thing. I have the one out of mine sitting in the garage somewhere came with the car don't know if it works?? But I wouldn't be surprised if there was one inside the rear where power enters the radio. Common when they did switch over from tube to solid state electronics (like these are).

 

Hope that helps and good luck let us know what else you find.

 

Scott

[Mo's70MCs]

Fred,

 

It looks like we're on our way, Doug (72-CLASSIC_RIDE) is got it under control and with the right answers I believe we can find your problem. First and foremost when working with anything electrical related, it's always wise to undo the battery. Any live (hot) wire shorted to ground can be catastrophic. Specially when a lot of the vehicle's wires are bundled together. You seem like a smart young man and if you take time to understand the task at hand, the rest will be simple. Most importantly giving the right answers to the questions at hand.

 

Since more than one person is giving suggestions, it is a bit difficult to get to the root of the problem. At times it can be a bit overwhelming and as if everybody is shouting. Connect the speakers to a secondary audio source for functionality. If the speakers produce sound when connected to another audio source, the problem may lie with the original audio component. The easiest way to trace the wires is with a common household battery (either AA or AAA – nothing larger). It will also check the functionality of the speaker, just brushing the leads to the speaker terminal will produce some static, it's process of elimination. If you're confident let's proceed. Although you can't beat Doug's tutorial so far.