I have a 1998 Honda Prelude base, 5-speed manual transmission. About 1 month ago, I noted that my radio would not turn on. As a test, I unplugged a GPS I had plugged into the cigarette lighter port and presto, my radio came back on. So I checked electrical going that and all tested good. I later learned that any light turned on in the cabin on such as the map light would kill the radio also. Also to note that both the GPS and the map light also did not work as well. If I turned off the map light the radio came on.

After much searching here and other places, I thought it could be the Electric Load Detector (ELD) which is located in the engine compartment fuse box. I did research to make sure I could find it. Where it suppose to be, it was not there. There was a place for one with the 3 screws that holds it in place. I have also noted that when looking for this part for a Prelude, I could find absolutely nothing. No part numbers or any information what so ever. I have checked every single fuse in both my cabin fuse box and engine fuse box and all checked with a Voltage Ohm meter. The radio itself had a fuse as well which I also verified is OK.

If anyone has any idea, I would greatly appreciate it.

 

I am just another DIYer. So, where to start to look for electrical gremlins??
I would start with cleaning up battery posts and cable terminals, grounding straps.
Then move onto the fuse box. Check for loose connections and corrosion in and around the box.
Go to radio and move wires while having the lights on that turn radio off
Check grounding points around the dash.

Wish you luck, hope you find the problem