Ive confirmed that 68 is Trans lip on this rig. But 71 appears related to a 94 diesel cruise control item.
35 is related to the IAC but I replaced both the IAC and the idle speed control actuator last year. I have checked for vac leaks. None found and engine idles nicely with no issues. The air conditioner works nice as well.
As for the trans code it also showed during my return trip home when I had Jerrys Clutch & Trans in Grants Pass, Or. resolve my limp mode. Both shift solenoids were replaced along with a new internal wire harness and he turned the force actuator up 1/2 turn. The codes pulled then were:
68 Trans slip
87 Shift solenoid A
I did replace my ignition switch the other day. While looking over the old one I found the orange wire was not seated all the way into the connector. When I grabbed it, it came out easily with close to no effort.
So the new switch is in and wires are all connected well. Seems to have had a positive effect on what I originnaly believe was a wonky temp gauge sensor. There were times when the dash gauge would read higher than I knew the engine was while trending with my IR temp gun.
For instance....IR gun would show 195-205 at T-stat housing yet dash gauge would show 230-240. I know the dash gauge is far from perfect and its normal to have it go to 220-230+ after a highway run or grade pull then exiting the highway (heat-soak). But that wasn't the case with mine. It would do this after just driving around town with little load on the engine. T-stat housing IR readings were normal 195-205F. Lower hose would range anywhere from 30-50+ degrees lower on average.
Now that I have replaced the ignition switch that seems to only happen after exiting a highway run but recovers after a bit. The temp sensor works off resistance measurement any added resistance via wonky wire connection can effect their accuracy.
During highway runs the dash temp needle would hover between half a dash needle width left of 210F to half a needle or so right of 210. I'm running a stock 195F T-stat (AC Delco). I just replaced all my hoses and installed a new t-stat Delco about 3-4 weeks ago.
Also used 2 cans of condenser coil cleaner on the AC condenser and radiator. Nice and clean now.