electrical help dash gauges

[tempefd]

I have a 69 F250 4X4 that I have owned for approx. 10 years now. I noticed last year that I might have some kind of electrical problem. When you start the truck up everything runs fine. After about 5-10 minutes all the gauges go the maxed out position and stay there. Fuel gauge goes past full, temp goes off the scale to hot, oil pressure goes off the scale to max. etc. The gauges will stay maxed out for a while and then all of a sudden come back to the normal range after maybe another 10-15 minutes. If you keep dirving it may repeat this cycle a few more times of maxed out and then back to normal several times. The gauges will stay maxed out for quite a while before coming back to normal. I have checked for possible ground wires off with no luck. It is hard to diagnose since it is intermittent. Any suggestions?? Thanks

[TNIceWolf]

Could possibly be an aging and going bad IPVR.