Testing radio speaker output?

[brucemillar]

Folks

My 124 has decided that I should not be able to listen any sounds other than it's glorious straight six and my Mrs Millar complaining that there is no moozak.

I have tried:

* Two different head units = same issue
* Removing the top of the fader switch and putting in jumpers = It was working in this config. It just stopped one day.

The car was fitted with with replacement door cards which rendered the rear door speaker useless. They were disconnected and the fader switch was removed with jumpers put into the base to give sound from ONLY the front dash speakers.

It had always worked like this. Then one day it just stopped. No drama. Just no sounds. I had bought a replacement radio previously (A Becker) so fitted that. No difference.

The antenna goes up and down when you switch the radio on and the radio displays the stations and volume. Just no sound. like it is fused?

How best to test please? Is there a fuse that I do not know about in the 124?

 

[optimusprime]

Bruce i think they have an amp in the boot .. And if you test the speaker with a 1.5 volt battery if they are ok it will pull the cone in when you put the battery to it .Both my speaker were rebuilt over at London some place .I do have the address if you need to do it .The speakers in my car were old Bloupunkt so not replacable . But not cheap to repair .Working as normal now. Have you put a piece of wire in to the ariel socket ? It could be the feed from mast to the ariel in the radio,or bad earth

 

[optimusprime]

Bruce have you the workshop manual thats floating about ? The info on the radio is in there .

 

[optimusprime]

Bruce me thinks your having a nice holiday some place ..When your home .
Let me know how you get on with the speakers ..

 

[Ted]

You can test speaker output with an old speaker if you have one.
Failing that, put a testlight (yes you've heard this before ) across the output. You will see it illuminate in time with the music/speech, but be aware that at lower volumes there is hardly any illumination - stated outputs on head units are VERY optimistic.

 

[optimusprime]

Thanks Ted i knew there was another way .Only one i did know was the battery .

 

[brucemillar]

Well with no separate amp? the we have to be looking at straight thru wiring from the head unit to the speakers?

I note that the rears have dedicated plugs in each channel. So plan A. is to disconnect these and try again.

Plan B. Remove the front dash speakers (I was hoping to avoid disturbing the dash) and test again. It has to be short somewhere in the speaker wiring, if we have no fuses and no amp, all we have left is wires.

Thank you Ted (as always) for the Test Light tip. That shall be my weapon of choice.

 

[optimusprime]

Bruce its easy to remove the speaker covers from the front . They to will have plugs on if original speakers ..Wonder if the rubber suspension cones have rotted through,mine had .So no sound ,well very little . Looking like pulling the radio out to check out the wires ..Did you know about the amp in the boot area?. By the way the manual will have info on removing the grills .The strip as to be lifted so you can get to the screws.

 

[brucemillar]

[QUOTE="optimusprime".Did you know about the amp in the boot area?. .[/QUOTE]

No. This is a 1987 Estate? Where is the amp in the rear?

Sent from my iPhone using sausage fingers.

 

[optimusprime]

At the rear of side moulding on the right in my manual but its not reliable as its left hand drive Did you have the local manual thats floating about ------ MODEL 124 MAINTANANCE MANUAL INDEX put it in google search the radio will be in item number 82-7833

 

[brucemillar]

At the rear of side moulding on the right in my manual but its not reliable as its left hand drive Did you have the local manual thats floating about ------ MODEL 124 MAINTANANCE MANUAL INDEX put it in google search the radio will be in item number 82-7833

No amp in my Wagon. According to the book. It would be in plain view under the antenna.

Sent from my iPhone using sausage fingers.

 

[Ted]

The battery method also lets you check the polarity of speakers it they aren't marked.
As taught on a Radiomobile course 1972.

 

[brucemillar]

What is somewhat troubling here: My wife just bought a (new to her) BMW X5. The sounds in that were all muted - Radio, Satnav, CD etc. This turned out to be a "common" BMW issue with the Becker Radio having blown all it's outputs. Not a cheap fix and a faff as the Radio is mounted under the battery in the boot. The mounting position being blamed for the failure(s). The radio has no ventilation and is subject to battery fumes etc.

I am hoping that I do not have similar here with my (new to me) Becker Radio? My Kenwood head unit is also not playing the speakers. Fingers crossed it is just a short as the fuse on the radio is intact. Just no output.

 

[optimusprime]

Bruce this is a good site to have by you --Kerrplonk.org every diagram you can think of .But its a search job ..

 

[optimusprime]

Look in the manual i sent to you , and on page to 82 then down to 82-7605 Lights and Radio. If you have one its in the boot driver side at the rear of tail lights .