Truck dies when put in gear, Help!

I have a 1996 Toyota Tacoma v6 3.4L 4wd, Automatic transmission. It starts up and idles fine, however when put into drive or reverse it just shuts off. I will add my temperature gage doesn't work. oh and it also dies when I turn the headlights on or use either of the blinkers which are all conveniently located on the same switch which I will be replacing. Also the truck would shut off if I hit the brakes which just so happened to be the brake booster, that problem appears to be solved.
I will add what's been to the truck within the last year. I redid all the spark plugs and wires, changed the oil, put a new alternator on it, new belts, new water pump and thermostat, new gaskets in the engine minus the exhaust manifold. All new vacuum lines, throttle position sensor, new brake booster, new half shafts, new exhaust and I think that's about it.

 

Did you have the battery tested? Did you check the ECU grounds?

 

If those are good, start looking at the trans' locking torque converter. I suspect the other two though.

 

It has a brand new battery I replaced that and the battery cables when I got the new alternator. What is an ecu ground specifically? is there a way to check the trans locking torque converter and the ecu ground? and do you know the approximate cost of these parts to replace I may just go ahead and replace them just to be sure. And I greatly appreciate the advice apparently neither of the two Toyota dealerships could figure this out.

 

Oh its also automatic

 

When you put it in gear, does it just shut off? Or does it try to go forward and bog down and die?

 

It just shuts off.

 

E-brake sensor is first thing that comes to mind.
However due to the other electrical issues it sounds like something(s) are grounding out.

 

well we replaced the part of the steering column with all the switches and it seemed to fix most of the issue. I can now put it into drive and reverse and turn the lights on. however when I hit the brakes all the lights on the truck seem to dim just a tad bit. and I also had it cut out on me while I was taking it for a drive. my temperature gage in my dash doesn't work, any thoughts? I replaced the water pump and the thermostat not to long ago.

 

You obviously have an electrical issue.

 

X2 on the iac