B7200 Electrical Problem w/ gauges

[kimbass]

Hi folks, my '86 B7200 HST has developed an electrical problem with the fuel gauge, headlights, and Charge/Oil pressure idiot lights. They don't work! (Tach and hour-meter are OK as are rear blinker lights). This began as an intermittent problem--they worked sometimes and sometimes they didn't. Now they are consistently not working. I've checked every connection I can reach behind the instrument cluster cover and cleaned every ground I can find. My operators manual must be a 10th generation copy because the wiring diagram is blurry and hard to follow. Any ideas?
Thanks!

 

[KennyV]

Check for corrosion at the fuses they have been known to be the bad connection in electrical circuits... KennyV

 

[kimbass]

Thank you KennyV--I have yet to check the fuse connections...once I find them. It's a great thought. I appreciate it.

 

[BrierPatch]

I wonder if it might have something to do with the key switch. I believe the blinker lights work whether or not the key is on, but the rest of the dash lights, I believe turn off with the key. Plus the engine does not need the key to be on to run either. In fact I believe the only thing the run position on the key is for the charging system and the dash lights. I don't have my WSM (Work Shop Manual) anymore so this is about the best I can do.

Good Luck.