Switching HU

[spearo2]

The display lights on my HU went out, so I bought another stock HU off the internet. Went to install it and the display does not come on at all. Did I get a bad HU or is this some sort of anti theft feature that I have to fix?

[mathteacher'04vibe]

I can think of two things to check:1) Make sure the yellow power wire on the a/m h/u is hooked up--without it you will get no power at all.Assuming you have power & sound...2) Check the dimmer switch wire (usually orange) on the h/u. I have always left them unhooked to avoid the trouble of not having a display. On my Sony, it works, but I have the option of setting the dimmer to "off" "on" or "auto--so it works with the light switch."

[ColonelPanic]

If you bought another stock one, was it out of another Vibe, or a different GM product? If it was out of a different GM product, it probably wouldn't work due to the anti-theft systems in place... Those radios communicate with the rest of the car to find out whether they should function or not... The Vibe's radio doesn't care, it has no anti-theft, just give it power and it should turn on and make noise. At any rate, if it were some sort of anti-theft issue I'd think the radio would at least show something...If you're seeing nothing at all, I'd check the fuses related to the radio, I think there were a few different circuits it runs off of. Otherwise, sounds like somebody sold you a crappy radio.

[spearo2]

I got one out of another vibe. Sound comes out and it will play cds, but the display is blank. I put my old one back in and the display on it works, but is still dim.

[ColonelPanic]

Bummer. Sounds like you got a bad head unit! Or, if GMJAP or anyone else familiar with the guts of these things happens to run by this post, they could tell us if there may be some connections between the display and a board that could have worked themselves loose...