cruising at 55 and it downshifted from od to 3rd and never went back to od. SES light came on. checked all fuses they all were good. checked all connections on the transmission itself and they seemed to be good. wiggled them and pushed them in for a better connection but they appeared to be connected. i dont have first, fourth or od. this the shift solenoid A?

 

That is a reasonable diagnosis. You can get a free scan at many auto stores to confirm that. Solenoids are trivial to replace.

 

Today I drive the truck to see if it was doing the same. Drove 10 miles and all of a sudden I had 1st 2nd 3rd and 4th again. Then after another 2 miles od came back also. I cut the truck off twice and it worked fine then after a few miles it lost everything again except 2nd and 3rd

 

Sounds like an intermittent electrical problem - could be a crack in the windings of the solenoid, a crack in the wiring of the harness within the trans, or corrosion in the trans connector.

If your budget allows, you can get a new internal harness with connector for $32 and a solenoid for $12:
http://www.transmissionpartsusa.com/...-00035400a.htm

IMO (although I am not an expert) that will very likely cure your problem without having to fiddle with it part by part.

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On further thought, unsnapping the old connector from the trans case can be a bitch. Therefore you might just start with the solenoid.

 

Why don't you actually get it scanned. That would help in this situation and would more than likely point you in the right direction.

 

I agree if you had a ses light on a scan would be the first step in diagnosing your problem. As mrvedit also stated , a broken wire could cause this problem. A specific code will help you from chasing gremlins and isolate the problem quicker.