I feel so stupid sometimes.... I am working on a friends Siverado and one of the things was burnt out bulbs in the faceplate of the factory base radio. I pull the radio out, and replace the bulbs, I had to wait about a week for the replacement bulbs to come in, because I did not have any on hand that were small enough..... so I go to put the radio back in and there is 2 places on the back for 2 plugs.... BUT I only can find one wiring harness and the antenna wire..... Because it'* not my vehicle and I've never pulled this apart before I can't remember if there were 2 wiring harnesses or in the back or just the one and an "extra" place for other vehicles (options)...... does someone know if the 2003 Silverado Base Model with the Base Radio sometimes can have only 1 harness plug'??

How many on the radio? (Pins)

24 on the big one that I have a plug for and 12 on the small one that I do not have another plug for..... so I'm wondering is the 12 pin one left undone?

just a guess but the extra plug might be for a vehicle with auxillary systems like Amp, rear controls like a suburban, etc.. just a thought

See what you get with it with just the one.

Here'* another mystery...my wife'* boss has left his truck fro me to work on while he is on vacation ....the backlight on the radio the bulbs where all burnt out ... I soldered in new bulbs then when I put it back in the backlights would never go off.... even when everything else was off and you'd left the truck ....what'* going on??

You have somehow soldered the 12V memory line to the bulbs.
The memory line is the line that is always hot and keeps the presets and all in memory. Follow that line and see where it got soldered.

That makes a lot of sense I'll take a closer look. I have done things like this for a long for the time and it seems like every time I solder bulbs there is a problem. LOL

Just check at where you did your work and you'll find it.

Are these the same vehicle or two different vehicles?