gerrychuck
Well Known Member
I just installed/had installed a 6.5" GRT HX in my 6A with a wiring harness from Stein. Works well, although I need to get back into the aft fuselage to shim the AHRS as it shows a 3.5 degree bank with the ball correspondingly off center. Oops, guess my homemade mount wasn't quite as level as I thought!
But I digress. The reason for this post is that the HX seems more than a little finicky about booting. Currently it is wired straight to the master, so it gets power as soon as the master is turned on (that will likely be changed, either wiring it to the separate radio master or a toggle switch). At any rate, it rarely boots successfully on the first try, either with or without an engine start. The first time I flew with the unit, it didn't boot, so after engine start I flipped the master off for a few seconds, flipped it back on again, and that time the unit successfully loaded. Tried the same again today, and repeated the process several times on the ground without success. Tried again a couple of times in the air; still no luck (I still have my original ASI and altimeter in the panel). Back on the ground, in the hangar, I flipped the master on and it booted right up. The tech that did the final wiring said that it may be very sensitive to voltage drop, and that made sense in the hangar, where I had much better luck if the battery was kept connected to maintainer, but today it was refusing to boot after the engine and alternator were operating, showing 14.5 volts. When it did boot, it was sitting on the hangar floor showing 12.5v. The only other variable I can think that could be involved is temperature; most of my failure to boot episodes were in the hangar at about 50 degrees F, but when it did boot today I had been working in the hangar for a couple of hours and had the temp at over 60. That doesn't explain the variability in booting up with the engine running outside, however, where the temps were below freezing both when it worked and when it didn't. Admittedly, colder today than the last time when it agreed to power up, but much colder than in the hangar on both occasions.
I will probably end up contacting GRT to get their wisdom, but thought I'd run this by the braintrust here first. I also need to contact the avionics tech again to see exactly what breaker he wired the unit to on the power bus. I'm quite puzzled at this point, and appreciate any thoughts or advice. Thanks in advance.
But I digress. The reason for this post is that the HX seems more than a little finicky about booting. Currently it is wired straight to the master, so it gets power as soon as the master is turned on (that will likely be changed, either wiring it to the separate radio master or a toggle switch). At any rate, it rarely boots successfully on the first try, either with or without an engine start. The first time I flew with the unit, it didn't boot, so after engine start I flipped the master off for a few seconds, flipped it back on again, and that time the unit successfully loaded. Tried the same again today, and repeated the process several times on the ground without success. Tried again a couple of times in the air; still no luck (I still have my original ASI and altimeter in the panel). Back on the ground, in the hangar, I flipped the master on and it booted right up. The tech that did the final wiring said that it may be very sensitive to voltage drop, and that made sense in the hangar, where I had much better luck if the battery was kept connected to maintainer, but today it was refusing to boot after the engine and alternator were operating, showing 14.5 volts. When it did boot, it was sitting on the hangar floor showing 12.5v. The only other variable I can think that could be involved is temperature; most of my failure to boot episodes were in the hangar at about 50 degrees F, but when it did boot today I had been working in the hangar for a couple of hours and had the temp at over 60. That doesn't explain the variability in booting up with the engine running outside, however, where the temps were below freezing both when it worked and when it didn't. Admittedly, colder today than the last time when it agreed to power up, but much colder than in the hangar on both occasions.
I will probably end up contacting GRT to get their wisdom, but thought I'd run this by the braintrust here first. I also need to contact the avionics tech again to see exactly what breaker he wired the unit to on the power bus. I'm quite puzzled at this point, and appreciate any thoughts or advice. Thanks in advance.