After market head unit (eclipse)in my 89 formula not working at all checked radio fuse fuse is fine anybody have any suggestions

 

Take the radio out, there should be a fuse on the back of the headunit. If that one is fine then check the radio fuse under the dash, as well as the accessory fuse, and there should be a fuse labeled ARC on the fuse block, make sure that fuse is good. I had an issue with my stock stereo not getting a constant and it ended up being the ARC fuse under the dash. If you did not install the stereo there is no telling what wacky wiring was done, so if fuses don't yield an answer make sure all the wires are still connected and insulated.

 

Some of the harnesses have an inline fuse between the headunit and the stock connectors. Not all Eclipse HUs have a fuse by the connector. Either way, pull the HU out and make sure there is power on the red and yellow lines.