Car Radio Keeps De-Setting.

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Re: Car Radio Keeps De-Setting.

Postby Fat Fingers » Wed 02 Aug 2017 6:45 am

Well tht is an option and would work but you need to measure the current drawn in the memory circuit and I sugget you will find that a large capacitor say 5000 uf and a diode would work BUT the internal memories will be on 5v and if it cranks and starts well I would not spend on a battery , have you given it a 24 hr charge recently ?....why has he not tested the battery ..load of .3x the AH capacity in amps for 15 seconds ..if it goes below 9.6 its faulty ..or one of the new digital battery testers ..Have you checked if the alternator is bringing it up to 14.4v on the road ?.You cannot say the battery goes below 9v by just putting a digital voltemeter across it because the meter samples the voltage ,you need the type that draws a graph or has min max function ...try the two wires direct to the battery first because the radio is designed to work on a battery cranking an engine and you had this before ...and dont forget and clean the battery terminals .
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Re: Car Radio Keeps De-Setting.

Postby JulianBrown » Wed 02 Aug 2017 8:14 am

Fat Fingers wrote:Well tht is an option and would work but you need to measure the current drawn in the memory circuit and I sugget you will find that a large capacitor say 5000 uf and a diode would work BUT the internal memories will be on 5v and if it cranks and starts well I would not spend on a battery , have you given it a 24 hr charge recently ?....why has he not tested the battery ..load of .3x the AH capacity in amps for 15 seconds ..if it goes below 9.6 its faulty ..or one of the new digital battery testers ..Have you checked if the alternator is bringing it up to 14.4v on the road ?.You cannot say the battery goes below 9v by just putting a digital voltemeter across it because the meter samples the voltage ,you need the type that draws a graph or has min max function ...try the two wires direct to the battery first because the radio is designed to work on a battery cranking an engine and you had this before ...and dont forget and clean the battery terminals .


Oh dear. This is getting very complicated for my layman's brain! I'll pass on the suggestions here to the auto electrician when he visits next week.
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Re: Car Radio Keeps De-Setting.

Postby paintman » Wed 02 Aug 2017 8:47 am

Easiest part of FFs suggestion is the two wires direct to the battery.

Done something similar to the headlights on my RRC to bypass the dip switch which is a known issue - and on other vehicles using the same dip/main/flash column switch. The light now get their supply through relays which are switched by the column switch instead of it passing through the switch.
Obviously these are fused and I presume an appropriate fuse in the live somewhere near to the battery would be required for your radio?
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Re: Car Radio Keeps De-Setting.

Postby ANDYHUBBARD » Wed 02 Aug 2017 9:12 am

Strongly recommended.
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Re: Car Radio Keeps De-Setting.

Postby Fat Fingers » Tue 15 Aug 2017 7:35 am

Have we got this fixed yet ?

or did it turn out to be so stupid we will never find out !
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Re: Car Radio Keeps De-Setting.

Postby JulianBrown » Tue 15 Aug 2017 8:08 am

A new occurrence! With the engine running and headlights on, digital radio cuts out when I switch on or flash the 52" roof light!

This gets more problematical by the day!
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Re: Car Radio Keeps De-Setting.

Postby Fat Fingers » Wed 16 Aug 2017 6:57 am

Thats an earth fault ..."when operating one circuit causes another to go on or off its an earth fault"

The radio is using the roof lights (via the filaments) to get its earth ..when the lights come on it looses its earth and gets a +12v.
You need to run a cable from the radio case /earth wire to the battery neg . This has probably been your problem all along.
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