Dash lights out after cd/radio

I just bought a 95 Grand Cherokee and a Jensen cd/radio was installed before I picked up the vehicle. The dash lights worked before install but not after.... I am 1000 miles away from the installer and have to fix it myself ----any ideas about what the idjit might have done wrong? Where to start looking?
Fuses are fine and the stereo illumination is constant-My dash light dimmer switch does nothing

It sounds like someone tried to hardwire the radio without using a Metra harness.  The factory dimmer wire was probably used as a ground which fried the dimmer switch.  Remove the black wire in the Jensen harness from the suspect wire and connect it directly to a suitable ground (screw into metal behind the dash). 

The dimmer switch will more than likely need replacement as well.  You wrote that stereo illumination is constant- does that mean the display stays lit up all the time?  If so, do a search on your model radio and see if it's supposed to- my guess is that it's not.  I'd probably disconnect the dimmer and illumination wires completely from the harness.  As long as the unit has constant, accessory and ground it'll power up fine.

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My ex once told me I have a perfect face for radio.

Thanks for the help---I meant that when the radio is on that the display stays at a constant level of light, it doesnt dim when I turn the dimmer light switch either(just thought that might mean something)

Im trying to figure out how to get the radio out of the dash, once I do Ill let ya know what the wiring looks like--I went and bought a new dimmer switch in case it is fried

Thanks

Most aftermarket radios don't have a dimmer control, but some have an illumination wire.  If this is hooked up, whenever the parking lights are on the display will dim a set amount (not adjustable).

To get the radio out you have a few choices- if you have Jensen radio keys then it should slide right out.  If not, you can remove the dash bezel, and unbolt the whole kit.  Otherwise, you can have a stereo shop do it, for a small amount- it shouldn't take but a minute or two.

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My ex once told me I have a perfect face for radio.

When you get the radio out, there should be a red wire on the factory wiring. This is your illumination wire. connect it to your illumination wire on the jensen if it has one. Most ill. wires are either orange or ORANGE / white stripe.

Thanks for the help,

The Jensen only has red to Battery, Yellow to Acc, black to ground, Blue to pwr antenna, and speakers. So-
Must be as you said the black wire must be the culprit if the radio is working fine--

Im still trying to remove the radio, anyone know if I can fabricate the removal keys? they arent the DIN type they are the long flat type.

Fabricate keys, are you kidding me?  It'd be quicker to just remove the kit from the dash.

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My ex once told me I have a perfect face for radio.