I have a Max/Radius series that "forgets" what channel it's on when the vahicle battery switch is off for a few hours.
I know there is a battery or a capacitor that is to keep memory. Where is this at on the board? If it's a capacitor, can it be replaced with a lithium battery and of what voltage?
thanks!
Radius/Maxtrac channel memory
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Heres the way the radio should be wired. The main power connector should be HOT or powered all the time. Using the 16 pin connector, there is one pin that gets switched power. Inside the radio there is a small jumper that gets cut to enable the radio feature. Diagrams and instructions are available here on Batlabs.
I know that's how it's supposed to be wired, but in the real world, not one installer I've ever met does this.
As I found out, the repair is to add a 3 volt lithium with a diode parallel to the 47uf capacitor at pin 2 of the CPU. This keeps the capacitor charged on vehicles that must use a master shut off.
As I found out, the repair is to add a 3 volt lithium with a diode parallel to the 47uf capacitor at pin 2 of the CPU. This keeps the capacitor charged on vehicles that must use a master shut off.
If the radio is wired hot all the time and the on/off switch is used on the radio, you don't have this problem either.On 2001-09-24 23:38, jim wrote:
I know that's how it's supposed to be wired, but in the real world, not one installer I've ever met does this.
As I found out, the repair is to add a 3 volt lithium with a diode parallel to the 47uf capacitor at pin 2 of the CPU. This keeps the capacitor charged on vehicles that must use a master shut off.
If you want ignition control, get an installer who doesn't cut corners and wires it like it is supposed to be wired.
There is a reason for not switching the full supply to the radio on and off all the time, it is so the voltage/current surges don't blow up the PA or other important components.
If you are going to pull the radio to add a lithium battery, why not just cut the ignition sense jumper and wire it properly instead?
Bat
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Simple. The department that owns this vehicle wants EVERYTHING....i mean EVERYTHING to turn off with the battery switch because they had a fire engine catch fire last year in their garage and they are being paranoid now! You should see the problems with the laptops when they don't properly shut down Windows then switch the batteries off. One problem at a time!
I can see that asking for help is useless with certain people. This question has been answered more than once on Batboard without the smart remarks about proper installation. Yes, I pulled the radio. No, I did not hot wire it- that is not what they wanted. They were not willing to pay to have it hot wired. They were, however, willing to pay $$ to have the channel retain and not have anything on the vehicle hot when shut down.'
As for surges, I have not ever seen or heard of this on a properly operating vehicle. In conversation with two other local techs from other companies (yes, I talk to competitors) they have never heard of surges or spikes doing this, therefore I worry not. At least the CDMs don't have this problem!
THE END.
As for surges, I have not ever seen or heard of this on a properly operating vehicle. In conversation with two other local techs from other companies (yes, I talk to competitors) they have never heard of surges or spikes doing this, therefore I worry not. At least the CDMs don't have this problem!
THE END.