Garmin 178C GPS won't stay powered on

[Blue_Runner]

Just found interesting info via google. Here is what someone else said:

Garmin 178C Stays on for 20 secs then turns off

Had the same problem. Cleaned the connector which I thought fixed the problem. That was last year. Now I have to turn it on a dozen times or so before it will stay on. Turns on for 20 sec then shuts down. Turn on 12 x's and it finally stayed on. Don't know what will happen next time I'm out. Can't have this happening on a night trip. According to Garmin Website this is a discountinued model. Hoped someone else had problem and fixed. Thinking it maybe a thermal prob. W/O schematics hard to TS.

I had the same problem. In your settings you can set this thing to monitor your battery's power so it auto shut down if your battery goes below 11.2 volts or so. I disabled this and it has worked ever since.

Then another poster says this:

On mine, it was the power cable itself. I had been living with sporadic shut downs for several years. Then I sheared off my transducer. When I replaced the transducer, it forced me to a new power cable. Problem solved. I should have known better, my street pilot 3 and my colormap both had similar issues that a new power cable resolved.

I'm gonna install the cable regardless but curious about this battery monitoring setting. Come to think of it my battery was a bit week at the ramp that weekend....interesting.