radio memory saver
Thread Starter
Safety Car
Joined: Nov 2008
Posts: 4,368
Likes: 9
From: Colorado
radio memory saver
So I have a quick disconnect and a battery tender wired to my car. I lose all radio presets when I use the disconnect and I know there are devices for supplying a small current to the radio to retain the presets when the disconnect is open. I want one that can be added to my current setup and be contained in the battery compartment which is kind of crowded already with the disconnect and tender. I can find items that connect to the cigarette lighter or plug into the OBD (like I have one of those), neither of those are battery compartment contained. Anyone have a source for this?
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
I have a small wire that jumps across the disconnect with an inline fuse in it.
With the disconnect open, my radio memory and clock are the only thing running, checked with an ammeter and installed the smallest fuse possible.
Then opened the door, courtesy lights came on and instantly popped the fuse. Changed to LED bulbs, re-checked the amp draw and now it's all good...unless you forget to close the disconnect and turn anything on... but I've NEVER done that
M
Thread Starter
Safety Car
Joined: Nov 2008
Posts: 4,368
Likes: 9
From: Colorado
I have a small wire that jumps across the disconnect with an inline fuse in it.
With the disconnect open, my radio memory and clock are the only thing running, checked with an ammeter and installed the smallest fuse possible.
Then opened the door, courtesy lights came on and instantly popped the fuse. Changed to LED bulbs, re-checked the amp draw and now it's all good...unless you forget to close the disconnect and turn anything on... but I've NEVER done that
M
So courtesy light change to LED lowered the draw, good idea. I was thinking more of a way to add in a 9v transistor radio battery for power when disconnect is open. It's small potatoes but I tend to not use the disconnect as much due to the radio being a pita to reset.
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Not sure how much draw there would be on that 9 V battery, but you can accomplish what you want with a couple of diodes. Connect the cathode of both diodes together and wire that to the radio for the preset memory. Then you connect the positive feed from the car to one of the anodes and the positive from the 9V battery to the other anode of a diode. The negative terminal of the 9V battery would be connected to ground. This will provide power to the radio preset memory when either the car supplies power and/or the 9V battery is good and would isolate the 2 supplies.
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
Not sure how much draw there would be on that 9 V battery, but you can accomplish what you want with a couple of diodes. Connect the cathode of both diodes together and wire that to the radio for the preset memory. Then you connect the positive feed from the car to one of the anodes and the positive from the 9V battery to the other anode of a diode. The negative terminal of the 9V battery would be connected to ground. This will provide power to the radio preset memory when either the car supplies power and/or the 9V battery is good and would isolate the 2 supplies.
If you are going to add a semi permanent 9v connection you should isolate it.
I don't think the 9v battery will last as long as you hope it will, seems to me I looked at those that plug into the cig-lighter when disconnecting batteries and was surprised as how little time was actually available
M
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
I had the disconnect on the negative post with a fused jumper across it so the clock and radio would have continuous ground. I used a 5 amp fuse that would handle the courtesy lights but would short if there was a dead short elsewhere in the system. Worked great except that the battery tender would blow the fuse. Not really sure why as I could leave it for days without the tender hooked up, but it would blow overnight if I hooked it up. I thought about putting the disconnect on the positive side and running a wire directly to the radio keep alive and clock bypassing the disconnect. I think this would be the best way to solve the issue. A single wire with a three amp fuse at the battery would work and no power would be anywhere else on the car.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer