I have a 95 SC 4x4 XLT with 5.8L with about 117K mileage. I don't put many miles on it as I have 06 Mustang convertible daily driver and 2 dent side trucks.

Minor problem 1: My cruise control hasn't worked since I've owned the truck. A dealer told me a couple of years ago that I need a cruise control module to the tune of $700. I didn't do it prior to a 3K road trip although I kind of wish I had as my leg was kinda sore from having to push the go pedal so much. It seems kind of pricey, but then I haven't tried to work on these more computerized trucks.

Minor problem 2: Oil pressure gauge will usually start normal, and then go to maximum reading... stay that way for about 20min, and then return to normal. Lately the Coolant gauge has read maximum-overheat and then snap back to normal. Tonight the coolant started high, and then when it snapped to normal, the oil pressure went high. My gut reaction would be that a sender wire having a bare spot somewhere and grounding. I haven't tried to look very hard though. Again, with the computerization, could it be more complicated? And what if I wanted to get an aftermarket gauge, would I be creating a problem for the EMC to disconnect the coolant sender to use an aftermarket sender/gauge?

Not a Problem: My truck has the dressier aluminum tailgate panel. I like the look of the tailgates that don't have the panel better. What might I find if I try and remove the panel? Fastener studs and plastic fasteners? Would I be better off to find a plain tailgate and paint to match? Unfortunately I have two tone paint with tape striping separating the colors.

The good news is that the engine and transmission run well. I replaced the automatic hubs with Mile Marker manual hubs since the automatic ones wouldn't reliably engage. I call the 95, my "new truck" compared to my 76 and my 79.

 

If it is the Speed Control Module you should be able to pick one up at any pick-n-pull or salvage yard.
You have cluster problems and this may be why the Speed Control does not work.
The cluster operates the speed control by sending speed information to it.

What transmission do you have?

Does the speedometer work OK?

After 1992 or 1993 do not know the year the oil pressure gauge had one coil missing so the gauge would only go half way up the scale. You say yours is a 1995 if so and gauge pegs then someone has replaced the cluster with the wrong one or someone has done a oil pressure mod.
I did the oil pressure mod on mine and put a gauge from a 1992 in my cluster and on a cold day with the engine cold it will peg until the engine warms up.

As far as the temp gauge it has a dedicated sender on the engine to operate it and has nothing to do with the computer or the running of the engine.
The computer use a temp sensor and its temp sensor has nothing to do with the gauge.
The temp sender only has one push on wire.
The temp sensor has two wires and is a plug on.

You may also have a body ground problem. I would check the ground wire from the NEG (-) post of the battery to the stud on the fender.

 

I have an electronic overdrive automatic.

My speedo seems to work fine as well as Tach, fuel and voltmeter

I don't see any evidence than any PO has tried to modify the gauge pod. Aside from an aftermarket stereo, running boards, trailer hitch receiver, and the manual hubs (I had installed) everything about this truck looks unmolested and looks to be in very good condition.

When my oil pressure looks like it's working normally, it doesn't seem to move to correspond with RPM. Aside from snapping to a full maximum position (as if it's grounding out) it always seems to read in the normal range or just slightly more than mid point.

When it is particularly cold both seem to work properly. The Temp gauge will generally read slightly lower than midpoint in the normal range after it warms up. It does build from cold when I am starting cold. When it seems to be mis-behaving ( a relatively recent phenomenon) it will quickly snap back to it's normal reading and hasn't seemed to read high for very long. This seems to only happen shortly after being started... after 20 min or so, both gauges seem to settle into normal.

 

My dash gauges would go wacky like yours every once in a while on my old '92 F350. In the process of removing the dash cluster I found one of the rear connectors almost ready to fall out. I popped it back in, checked the others, then re-installed. Problem solved.