I have a TRC 458 cb.... it keeps blowing fuses

Hi Carl, I found 2 different hook-ups so I will list them both. You can check them out according to the wire colors you have in the mic cord. First one and this may be for a turner mobile mic. ;
Turner
1- Shield & Red
2- N/C
3- Blue
4- White
5- Black
Yellow NC

This one is out of the Turner book but they did not list your radio exactly. This is the most popular hook-up for Realistic's.
Code E;
1-S
2- N/C
3- Bk
4- Wh
5- Red
Hope this helps, Mike

http://www.cbtricks.com/mic_manuals/turner/turner_mic_wiring_book.pdf

google it

This uses a uniden board and has a relay for transmitting, check and clean the relay contacts

when mic is pressed transmitter is engaged. First is the Fuse the proper fuse? Could be an antenna-coax problem. Get a dummy load and hook up to your CB and try it again. If it doesn't blow the fuse, the problem is indeed in your coax antenna system. another way to test your antenna coax is to disconnect it from the radio, take a multimeter, set it to ohms 200 ohm scale, put one lead on the center pin of the coax and the other on the outside of the connector on the coax.if it shows anything at all, you have a short and that will not work. It needs to not read anything. To be sure the antenna system is ok other than swr you can also check the coax an antenna for continuity. one lead of meter on the coax center pin then other on the antenna. should get a reading, a low value. again on the outside of the coax at the connector and at the antenna side on the outside of the coax connector. should be a low reading. but you cannot have a reading from the center of the coax to the outside of the coax. disconnect the coax at the antenna and measure from center to outside at the coax if the previous reading showed a value.If you see a value on the meter, any value, your coax has a short. not good. most likely at the coax connector. redo the connector. It is possible that the coax got compromised somehow and got smashed to the point the outside coax meets the inside and touches.
Now the other possibily your fuse blows, kis because the final output transistor is bad. So if you hook up a dummy load to your radio and the fuse still blows, then the final transistor is bad. This is probably due to a bad coax-antenna system. So before you replace any parts check the coax-antenna system first or you will have the same problem and burn out another transistor in the final. If none of this helps then just get another radio or have a god buddy look at it that knows about radios. Trade him another radio or something to fix it.

we need to know what kind of mic are you hooking to it?

After installing the antenna, follow these steps to adjust the
standing wave ratio(SWR).
1. Turn on the CB.
2. Set S/RF/SWR/CAL to CAL.
3. Key the Mic and rotate SWR CAL so the meter points
to CAL.
4. Unkey Mic.
5. Set S/RF/SWR/CAL to SWR.
6. Key Mic again and note the actual measurement on
the SWR scale. Refer to the following table to interpret
the reading.

1:1 - 1.5 Great
1.5 - 2:1 OK
2:1 - 3:1 Not So Good
Higher than 3.1:1 Terrible

The ideal standing wave ratio (SWR) is 1:1, or a meter
reading of 1 on the SWR meter's top scale. A SWR ratio
of 1.5:1 to 2:1 is excellent for most mobile CB antenna
applications.

Check the SWR on Channel 1 and Channel 40
If the SWR is higher on 1, make the antenna longer
If the SWR is higher on 40, make the antenna shorter
Most antenna's are adjustable. Make small adjustments at a time.

yes the problem is a diode on the input of the rig. this is black with a silver band at one end it will need replacing as it has shorted out.

Does this radio have a pa/cb switch and if so is it on pa?

Hello Adam, first off, do not unhook the antenna then key the mic; you run the risk of blowing the final transistor out of the radio, then it will not TX.
The digital TX lights can be adjusted high or low by a cb tech. All they are is a general reference as to how much power is being dead keyed; usually around 4 watts.
For the best performance, the antenna needs to have the SWR set with a meter so all your signals are getting in and out. A mismatched antenna system can lose you about half of your power and range; and that's hard on the radio also.
If your radio was tuned up by a shop tech, you would see the digital go part way up, but when you talked into the mic, the digital would go almost all the way up. I hope this clarified the situation for you,,, Let me know,,, Mechanic

Want to wire cobra mic to a uniden washington radio