Thanks RedRam10 I'll be mavrek at email@example.com .. I just got this 89 D350 Truck I'm getting strange readings the eng. temp senc.. shows around 600 ohm's when I turn on key it go's to 1.99 meg ohm's .. OC sencer voltage when warm is almost 20VDC ... I don't have any bad eng codes .. 1-2,,3-3,,5-5 the 3-3 strange .. Truck don't have AC.. I have induced problems to ensure I will get codes .. then clear them ..