if my cb radio keeps blowing fuses what is the problem?

Answer 1

You don't say if it works at all before the fuse blows. You also don't say if it's an inline fuse in the power wire of the radio or if you've tried a direct hookup to one of the fuses in the fuse box of the vehicle.

a) Fuse blows when it's connected to power
b) Fuse blows when you turn it on
c) Fuse blows only when you try to transmit

a) Unit is NG or you've got a short in the wiring between the radio and the vehicle power
b) Unit is NG or you've got it wired backwards (make sure you're black to ground, red to +12V)
c) Unit is NG or your SWR is SO bad (lousy antenna connection, antenna short or *really* badly tuned) that the the current draw is more than the unit's fuse can handle.

If you do have an inline fuse, is it big enough?

Answer 2

A few folks have pointed out that you have not filled in much in the way of details; this makes it difficult to make a good guess as to what is wrong.

I will, however, make a couple of assumptions. One, that the unit is a mobile unit and two, that the thing did work.

You might remove the cover and look inside. See if any components are discolored. If they are, it is quite possible that the radio suffered a voltage surge - either from a bad regulator in the vehicle or you had the unit on whilst jump-starting the vehicle.

If that is the case, there will likely be a shorted capacitor or two and the final transistor will also likely be shorted (which would explain why the fuse blows when you turn it on).

Under no circumstances should you put a "stronger" fuse in the unit. Should you do so, it may be possible that some wiring or printed circuit inside of the radio may melt and then you will have a worthless piece of junk instead of a repairable radio.

If the radio suffered from exposure to over-voltage as I mentioned, many shops may refuse to repair it as they will have to guarantee the repair - and almost any component in that radio may go at any time after being subject to over-voltage. That said, the radio can likely be repaired so long as you can find someone to do it and will probably function properly after replacing the damaged component(s).

Good luck!


Best regards,
Jim

Answer 3

The problem is you don't provide enough details to get a really GOOD answer. You need to provide the CIRCUMSTANCES under which it blows, ie power on, just plugged it in, trying to transmit, just sits and blows after awhile, etc.
Is this a new installation, or an old one? New, check your wiring. Do you know the proper fuse size for the radio? If you spliced into another power wire somewhere, you could be drawing way too much current for that wire to run an accessory, it's always best to use a direct connection to the fuse box or battery with an inline fuse.
Get back with a better description of WHEN the fuse blows, and some details on the installation ( new, old, you just changed something, etc. ), and maybe we can help you.
- The Gremlin Guy -

Answer 4

what type of cb do you have just double check the ground an put a bigger fuse in it, your probably just drawing to much power for the fuse, dont go over a 20amp

Answer 5

yan got the wrong size fuse or a short

Answer 6

Blown rectifier.

It's a simple fix if you're electronicaly inclined.

Or you're hooking the power and ground wires up backwards.

Answer 7

i would say you have a short make shure you got black wire grounded to chassis

Answer 8

make sure you have it wired properly, red to hot and black to ground.