Yes, that could do it.

The OEM radio needs a +12v signal to mute, which is opposite of all after-market stereos (which need a ground). The relay just converts the +12 signal to a ground. The problem is the OEM radio only needs a couple milliamps to mute so Honda didn't engineer the mute signal to provide the several hundred milliamps that some auto relays consume.

Try to find a low-current relay, some are as low as 15 or 20 milliamps. If you have an ohm meter measure the coil resistance of the relay, if it's 300 ohms or more you should be OK, 500 ohms or more is preferable. You'll probably find yours is between 100 and 200 ohms, too much current is needed to drive it.

 

Thank you very much for your reply. When I look at the three diodes on my board, there appear to be two different manufactures. I was thinking, perhaps it's just down to pot luck, if some boards were assemble with one manufacture's components and some another, maybe that is why some get damaged and others are ok using these Autoleads patch leads? I will check resistance now and post back.

 

I just tested resistance and it's 80 ohms! Thank you so much for your help, it's so nice to be able to be able to work through a problem and come up with a very likely conclusion. I'm really quite pleased, I was sure my installation was good, so was getting a little frustrated. Again, thank you very much.

 

X2

Also, today my new transistors came. So I removed TR3(was not too difficult), and re-soldered the new one.

And bugger me, it now works again!

Think I'll leave the relay out for now until I can replace with a lower amperage, just in case. Although I guess its possible this new transistor will be more tolerant?!

For me, it's so satisfying being able to fix something I can't tell you. Thank you all, especially Modifry, as it's very unlikely I'd have got this done without your help. Bloody awesome!

 

Oh also, I now have a spare radio control panel should anyone be interested in it.

 

X2

Also, today my new transistors came. So I removed TR3(was not too difficult), and re-soldered the new one.

And bugger me, it now works again!

Think I'll leave the relay out for now until I can replace with a lower amperage, just in case. Although I guess its possible this new transistor will be more tolerant?!

For me, it's so satisfying being able to fix something I can't tell you. Thank you all, especially Modifry, as it's very unlikely I'd have got this done without your help. Bloody awesome!
[/quote]
I'm glad that you got it working again, but there shall be no buggery here.