I hooked up my cobra 29 wires backwards (first connection after purchase of cb) now it will not come on at all .i looked inside and the trace was burnt in one spot i replaced the diode and repaired the trace but still no power.

Check for fuse, inside box, as well as outside under the hood. Check your ground wire, not connected...when your groundwire is not making contact to
the body or other metal.. this problem will happen, or your hot wire is not connected to your fusebox...trace your hot wire to see if it is connected, if not connect to fuse box, and this might solve your problem. Hope this help!

Yes, if you have a meter check resistance (like reading a fuse) with the radio off and power cord removed.

Only two of the three pins (look at power cord to see only two have metal in them) are used.

With power switch on front in off position there should be no reading across the + to - pins on the back of the radio.

If a short there the protect diode is shorted--likely first time it got hooked up backwards--easy to do.

Follow in this case the + pin on back just inside the radio and it goes directly to a diode. cut the diode if a short there and read again at the plug--if short gone replace the diode--radio will work without it but you will have no protection in that case.

Usually a 3 amp quick acting 3AG fuse---do not use the generic ones from Radio Shack.

If the radio got hooked up backwards look and test for a dead short across the power leads-----there is a diode just inside where the hot lead goes that will be shorted .

SD TECH

i gus i hook up the power up and blow some thing it is a black 29 cobra got aney thing to fix it

Take the cover off, look inside the front of the radio and you will see a tiny small bulb near the meter,it is held in place in a slot, has two wires, trace these wires down, noting where they go, unsolder them with a solder iron. You can purchase them at just about any electronics outlet,(Radio Shack), etc. Then install in reverse removal.....hope this was helpful....

did you look for power comming out of your power switch....
dont tell me that you hooked it up backwards. if you did check the imput diodes

the solid red wire is the battery plus or the hot wire. the red and black is earth or ground wire if the radio has been hooked up backward it may have blown the protection diode.

He is actually looking for the Microphone wiring which is a roadKing Mic to the Radio Cobra 29.

Looking at the plug from inside the radio, with the nub facing downward, from right to left you have pin1 pin2 pin3 and pin4.

1-Shield
2-Audio
3-Transmit
4-Receive

Colors are

1- Red
2-White
3-Blue
4-Black