Excessively High Gauges

[86RangerXL]

There should be a ground strap attached from the firewall to the engine. On a 2.9 its bolted to the drivers side head in the back. If you have a 4 cylinder i dont know. But thats the ground for cab electronics.

Also since you have an 86 your gauges actually do "read" to a point. They are still unfourtantly dependent on voltage though.

It wasnt till mid year 87 they switched to the gauges that are idiot lights with a needle

Alright, I'll check out the actual ground straps

 

[MISWFL]

My 1994 E150 5.0 had the exact same issue. Maxxed out oil and temp gauges, yet the fuel gauge read correctly. The charge gauge was low. Turned out the be a bad negative battery cable. The oil and temp gauges are phoneys, they are just idiot lights that look like gauges.