I'm having some weird radio issues and gauge issues that I'm sure are ground associated. The radio will light up but do nothing unless I smack the top of the dash, just above the drivers A/C vent next to the A pillar. This will also cause the oil pressure and volt gauge to move.

I've taken all under hood grounds off and cleaned them, plus removed the clamp on cab to frame ground under the drivers side cab, then replacing it by removing the slide on clamps from the strap, drilling holes, and mounting it with bolts after cleaning the frame and cab area.

Under the hood, below the wiper motor, is a ground lug with a nut on it. When I removed it the stud came out with the nut. After separating the nut from the stud, I replaced the stud, wires, and nut. My question here, does the stud thread completely into the cab and have ground wires and a nut on the in-cab side, behind the dash area?

 

see Subfords post #2, pic 3, and 4 shows
Looking for ground connections - Ford Truck Enthusiasts Forums

 

Thanks. I've seen those and checked and cleaned all the under hood locations. Next are those behind the kick panels. I've read somewhere that on the '87 models there are some grounds to the firewall behind the dash panel. I don't want to be tearing the brittle plastic dash apart only to find no ground connections.

In some things, the '87 had some different stuff going on.

 

I just checked the kick panels. It seems the '87s don't have any grounds there.





I did find a 2 wire ground on the bottom of the fuse panel. It was corroded under the wires, so I cleaned it up well and put the wires back.





Thanks to the pictures posted by torq'ta 5 8, I also found one wire I missed under the hood. I removed the wire and cleaned a little corrosion and put it back. The radio problem is solved it appears. The oil pressure gauge and voltmeter are still erratic, but have been for the 28 years I have owned the truck. I have read this is common for this year, so I guess I'll live with it. I am going to put in a manual oil pressure gauge in the coin holder just to be on the safe side, since the gauge has gotten worse lately.

Thanks to all who responded.

 

Finally found the radio problem, but not without a good bit of checking wires, grounds, and fuses.

It wasn't until I noticed the interior light wasn't working that I was able to zero in.

It appears there are at least two, maybe three fuses that operate different aspects of the radio.

The radio would light up the back lights, but no numbers would show on the screen. An AM station would play, but I was unable to change to another station. The only **** or button that worked was the on/off **** and volume.

Once I finally noticed the interior light was also not working I researched what all operated off that circuit. I had already pulled and reinstalled all fuses, replacing two that appeared to have gotten pretty warm over time, but were still good.

I pulled the interior fuse and saw a spark as I pulled it,. The blade fuse looked perfect. I had a new 15A laying there, and put it in. Bingo... Interior light came on, and the radio started working as it should.

Still haven't figured out what was wrong with the fuse that came out, just threw it away and was glad the radio and all lights are now working.

Going to try and find time this week to install the aftermarket oil gauge and voltmeter to go along with the untrustworthy originals.

 

Got my new voltmeter and oil pressure gauge installed. My truck actually has much better oil pressure than I thought, and the alternator is putting out better than thought also. I was getting afraid to drive the truck since the original oil gauge would dip to way below normal at times.