blueduramax

New to me 2005 SL500 - When I shut motor off, then turn it on again the radio always is on 87.7 FM. When the radio was turned off with the ignition it would be on another AM station. Which means I have to re-select AM and a station each time I get into the car. I have searched the command manual and read many threads with no answer. Is this just a part of this radio system I have to live with or is there a way to get it to go back to the previous station it was set to when the ignition was shut off? Keyless go is only option.

kbob999

I don't have this issue, but I thought of something...have you saved your favorite stations to memory?
If not, the radio may be in default power failure mode...which is no stations saved...and restarts with the lowest number on the 'dial'.

I don't recall how station memory works on the 2005, which is different than my 2003. Manual should tell you how to save a station.

next2pool

It could also be the radio constant power input is not there. Even with the key off, the radio needs a constant power on signal in order to maintain the station memory. Not sure which fuse that would be.

chad500sl

Try programming a preset by holding the number 1-9 down for a few seconds. If the radio won't remember the preset, you may need to do a reset under the SERV menus. I have two 2005 SLs and both remember radio stations without issue. There is also an option auto program presets somewhere.

I think 2005 NTG1 only has three wires connected to it (power, ground, can bus) and two fiber for the MOST loop. The radio should remember CD selections, which screen you're in, etc.

blueduramax

Thanks for the possible solutions. Tried some of them but no success yet.

Dudeman

The NTG1 Comand always has power. It's put to sleep and awaken by a signal on the MOST bus. When you turn the ignition key on, the gateway sends a signal to all the devices to wake up. If your Comand looses it's memory (stations), then most likely there's a fault in the power, which is supplied by the consumer battery (in the trunk).

Have you checked that battery?

Do you see a message in the MFD saying that the consumer/convenience devices are off due to insufficient battery power, then they come back after a minute or two of driving?

blueduramax

The radio saves station as I set them. The rear battery is new and there is no warning that it is low or insufficient. I disconnected the rear battery for a few minutes to see if there could be a reset. Everything working. Every time I shut off car whether radio was previously shut off or was on a station, when I turn the motor back on the radio comes back on on 87.7 FM. Thanks for the clues however.

Dudeman

Then the only thing I can think of is that someone rewired the Comand to be on the accessory line instead of continuous power.

Pull the radio out, then pull the Wire harness out. The harness has the 2 MOST cables (orange) and 3 extra wires. I don't remember which is which, but one of the wires is the 12V. You can check it with a voltmeter while the ignition is on. Once you found it, turn off the ignition. If the 12V goes away, then someone rewired it wrong.


Edit:
I looked at my info from when I did my head unit retrofit. The Red/Yellow wire on that harness mentioned above is the 12V. If that wire looses the power when the ignition is off, someone wired it incorrectly.

chad500sl

NTG1 should turn on if you enter the car without a key and manually press the power button. This will allow you to check that the wiring is correct and not switched. I can't imagine your issue being power related as mine remembers stations even across a hard reset. Could it be that the radio, not the head unit, saves station data? I think the radio is next to the CD changer under the rear compartment. NAV is in the trunk.

Dudeman

As the OP already stated, the radio does remember the stations just fine, as long as the ignition is on. Once he turns it off, then starts it back up, the settings are all gone. That is exactly what happens if the head unit loses power.

The tuner is actually in the Gateway, which is behind the driver behind the rear panel, and it's attached to the side. As far as I know the settings are stored in the Comand unit.