Hello- my 77 f150 ranger is bone stock including the radio. The radio works fine but has no illumination. Is there a bulb in the radio? Or where should I start? Have searched the forums and can't find any radio issues that deal with illumination only. Thanks!

 

I believe there is a bulb behind the frequency screen? But it is internal and that may call for some taking apart of things, like the radio itself.
Here is a lead on wiring and a way to get it overhauled.

The OEM radio was powered by a GREEN 2-terminal pigtail. YELLOW with a BLACK stripe is switched power, BLUE with RED stripe is dash illumination. Do not mistake the BLUE with RED stripe wire for ground. The OEM radio grounded through its mounting chassis. The speakers were connected over a separate pigtail.
Ok I looked behind the glove box and found a connection the goes off the green and yellow. GREEN with YELLOW stripe wiring is hot-at-all-times power for the courtesy lamp circuit. Use that. There is a 3-connector pigtail behind the glove box (which also goes on to power the cigarette lighter).
It's not the stock radio wire because the stock radio didn't need hot-at-all-times power (EXCEPT the factory digital AM radio for clock memory).
solid black—power
blue with red stripe--dial light
black with gray dashes—ground
orange with green dashes--right speaker
white with green dashes--left speaker
Assuming an AM/FM stereo and stock wiring harness'.
Purple is ground, right speaker is white and left speaker is orange.

For OEM radio help, the guy to use is in Scottsbluff Nebraska. His name is Gene Cochran, and he works out of his house. He's a crusty old codger, but does some tremendous work. While he had the radio apart, he updated some of the internals and cleaned the heck out of everything. My total bill was $25! His number is 308 632-2520 (I checked with him at the time I collected my stereo, and he was OK with giving his number out) He also lined me out on the manner in which the old radios were wired (mine at least). The speakers are in series meaning positive from radio to positive on speaker #1, negative from that speaker goes to positive on speaker #2. Negative from Speaker #2 goes to Negative on stereo. Now the stock stereo rocks as loud as the little 5 1/2 speakers can handle!!!
While it's there you might see if he'll wire in an aux input jack. I had it done with mine, and it allows me to run my I-pod through it. Basically when the I-pod is connected it becomes the antenna source. Cost in parts was under $5. I set mine on a 12" extension so I could just drill a small hole in the dash by the ashtray, which I'm turning into a covert charging/storage station for my phone and I-pod, won't cost much more.

 

Radio: Dial Illumination: #1893 bulb

 

Getting the radio out is the hard part, then simply remove a few screws and take off the top part of the radio to replace the bulb

 

Radio removal: Remove both inner and outer radio ***** to see if it is hard mounted above or under the dash bezel cover plate. Proceed accordingly.

1. Disconnect battery, find the small spring loaded button on top of the headlight switch, push down and remove the complete **** and shaft.
2. Use a small flat tip the lock tab on the wiper ****, and remove.

If the radio has never been removed, you should need to remove the dash bezel next.

5. Remove the dash bezel screws, remove bezel. You should have a radio cover plate that might come off with the ***** removed or you might have to wait till the main mount nuts are removed.
6. Clean the radio's threaded mount posts very well (like brake cleaner on a small brush or elec contact cleaner. The will strip out very easy.
7. Unplug antenna and connector.
8. Use a deep set socket (that fits), sorry can't remember the size, and CAREFULLY remove the nuts.
9. Remove ash tray slide out part 1st and maybe the tracks, to make it easier to get to the ground/support bracket on the back side of the radio. One nut back side of the radio.
10. Remove radio out from under dash. Take your time and work it past the ignition connector and a few other things in the way.