AC making Truck run hot

Wondering if I can get some opinions here. My Tacoma is a 2009 2wd V6 and it has some miles. Issue is driving up a slight incline and especially a hill , it starts running hot midway up with the AC on . I have to turn the AC off and turn the heater on to cool it down for a few . The truck does not seem to have that problem on level ground. It feels like its only when going on an incline, even the slightest incline . I did everything I can think of . Radiator is only 3 years old. Fan is working , new thermostat, rad fluid and cap , hoses. Had the AC serviced a few months ago . I am thinking the compressor could be the issue. I did see somewhere that the compressor could make your truck work more if its going bad. The AC is cold, clutch seems to be working so I am second guessing weather its the compressor . I have never changed the compressor and she running 450k miles and I use the AC all year long . This happens without weight in the back. Any recommendation will be appreciated . Thanks

 

Has it ever had the headgasket replaced?

The AC load combined with hill accent might be causing just enough load to trigger combustion in the cooling system.

Does it ever have hard starts in the morning?

To me this seems like slight HG or fan clutch.

 

I'd guess low coolant or air in the system. Especially if it only happens going uphill.

 

Have you checked actual coolant temp? If so what temps are you running?

I've never seen an A/C compressor cause an overheat although if the cooling system is already struggling to keep the engine cool running the A/C can cause it to overheat.

 

When's the last time you checked coolant level?

 

Start with this
Check the temp of the lower rad outlet and the upper rad inlet with an IR gun.
This will show you whether heat is being removed from the coolant thru the radiator.
You should have a difference of at least 10°.

Your a/c compressor has nothing to do with overheating.

 

About 3 years ago I was losing rad fluid on long trips . I would get back from a 2+ hour trip to find rad fluid low the next morning . I wasn't losing it on the ground . My mechanic thought I might have a slight gasket leak. It was a bit weird since around town or even the hour drive to work I wouldn't lose any fluid. I ended up using a head gasket sealer and since then I haven't lost a drop of fluid on long trips. I still don't to this day . Even on the days its starts to run hot with the AC , I check the fluid in the morning and right up on the level. I replaced the fan 3 years ago with the radiator . It passed the only tests I know how to do on it . Try stopping it when engaged and seeing if it stops fast when engine turned off. Do you think I have a HG leak even if I am not losing rad fluid . I didn't think of that only because my fluid levels are good . Its starts up like a champ when its cold and hot

 

I will check this . Great idea .Do you think checking this temp under normal conditions will be affective or only when it does the over heat with AC ?

 

I have not checked the coolant temp . I don't have a digital readout in the truck. I have a 180 thermo in the truck. I was thinking about putting a 160 in but decided against it.

 

Thought to mention as well , I don't get any condensation dripping from my AC . It used to drip on the ground like any other truck or car but it stopped about a year ago. I told my mechanic about it and he didn't think it was a big deal.