Lights/Radio Electrical Query

[Ian Abel]

Hi All
Simple question for someone with more electrical knowledge than me!!! If i'm driving along and I have the radio on and then I turn the lights on the radio will stop working for a 5-10 seconds and then will come back on. Realize that its an electrical problem but can't see how the two are related.
Any ideas please

Thanks in advance

[Steve_D]

First thought is that they are possibly related if the radio has a display that dims when the lights are turned on.
However, I don't know how it would turn the radio off unless the radio has an internal fault. All the normal thoughts about bad earths would not seem to apply although they may share a common earth point at the top of the tunnel O/S under the dash.

Steve

[Loubaruch]

Your radio is possibly but incorrectly powered from a lighting circuit.

The initial surge when the lights are turned on could be lowering the volts to the radio.

When the lights have warmed up ( a few seconds) they will take less current and the radio voltage would return to a higher value.

Easy to prove just run a temporary +ve lead direct from the battery to the radio external fuse and see if the problem disappears.

[QBee]

Does your radio work without the ignition on?
If it does, that's the answer - someone in the past has wired the radio to be on permanently, and has made a less than perfect job of it.
In my car, the light switch is located right next to the radio, suggesting that is seemed like a good idea at the time to use that feed for the radio.