Jeremy airjer W

Check your throttle position sensor voltage. KOEO you should see .8 to 1.0 volts with the throttle closed.

What year?

Replacing the plenum gaskets is a good idea. There really isn't anything else under the plenum. Usually the holes that the sensors sit in fill up with water. Would not be a bad idea to replace the sub-harness for the knock sensors as well.

When its wonky its usually a ground issue. Have you looked to see if your tail/brake lights are working correctly?

Jeff, did you ever get this resolved? I don't see a high speed relay for a 2012? There is a blower motor module. The module should have a full time battery and a full time ground. Then there will be a control wire. The control wire should vary voltage depending on the speed request.

Here is what I would do. Hook up the trailer and turn on the 4 way flashers or hold the brake pedal down. Now you have a known good on the right side to compare to. Go to the fuse box under the hood and locate the "TRL L TRN" and "TRL R TRN" fuses (both 10 amp fuses). With either a test light or a multi meter check the fuses for power. should see 12 volts on both or the test light should illuminate brightly. If the right side does and the left side does not, unplug the trailer and recheck. If the left side fuse now shows power the problem is in between the fuse block and the turn hazard switch or the turn hazard switch itself. If there is good power at both of the fuses than the problem is in between the fuse block and the trailer plug. Power is going away as soon as you plug in the trailer which tells us there is probably a corroded wire in that circuit. If you where to measure the voltage at the trailer you will probably find there is still a small amount still present on the circuit. Corrosion = resistance = voltage drop under load. You will be looking for the yellow wire that runs from the fuse block to the trailer plug. There are typically connectors in the harness near the rear of the vehicle. Find that wire in the connector and back probe it with trailer connected. If there is 12 volts the problem is towards the trailer. If there is not 12 volts the problem is towards the fuse block.

Bad grounds make trailer lights do odd things. Tail llights work until you step on the brake then nothing works until you let off the brake. Tail lights off and all the lights flash when using the turn signal. It is likely not a ground issue.

The ford diagnostic tool... whack the blower with the handle end of a screwdriver with the blower speed set to high, and the key on. If the blower starts working replace it. If it still doesn't work check power and ground. One of the two is missing or you didn't whack it hard enough. Also these are notorious for burning up connections at the blower resistor/module. A good visual inspection will confirm that possibility.

Does it turn on at all? What happens if you give it a good whack?

Swap the tires side to side, of course.

Put your fuel gauge on in the night before. Then check your fuel pressure in the morning when you try to start it. I suspect that your fuel pressure is a tad to low to get the mechanical poppets to open. As little as 1 psi below the minimum is enough to cause a no start. Also when it does not start try adding a couple of quick shots of carb spray into the throttle body. It it pops off and continues to run you just verified it is a fuel issue.

You would be amazed at how many of these I uninstall to get customers back on the road. You would also be amazed at the number of calls I get where the aftermarket alarm/remote starts have left people stranded.

That would be a lot of work to keep track of qualifying, finishing, and to put together all the numbers yourself.

uninstall it before it leaves you stranded.

The "gasket" is not the problem. The EGR has a tube that runs into the plastic intake right behind the throttle body. Over time the heat from the EGR degrades the plastic of the upper intake manifold. The plastic eventually gives way and the cooling port that surrounds the EGR tube fills the engine with coolant essentially hydrolocking it. Most times a new intake plenum, and a set of spark plugs along with a new starter is all that is needed to make the repair after all the coolant is removed from one or more cylinders. I have not had one come into the shop with this problem in wuite a few years mostly because they have all been replaced with the updated plenum and EGR port.