I am in the process of installing an aftermarket water temp gauge with sensor. Pictured below at the rear of the intake manifold appear to be my sensor and sender if I'm not mistaken... just not sure which is which.
Question: Which of these should I install my new sensor into? The brown capped one the left.... or the green capped one on the right?

 

No educated guesses? I think I'll go with the green one and see what happens.

 

You ought to be able to disconnect them one at a time and see which one bumps the factory gauge. Unless it's completely FUBAR????

 

Good idea, I'll try that if I can pry off the connections. The dash temp gauge goes from 0% to just below 50% at all times when running... I know it's a lie and I've read about the problem. I tried the gauge fix tutorial suggested here which involves removing the cluster... and my tiny copper wire connection was intact and fine. So, I should be able to notice a difference in the dash gauge behavior by disconnecting the correct sensor/sender. Thank you! I'm looking forward to having a real temp gauge.

 

The sender for the temp gauge should be real small and uses a single wire connector using just a regular spade connector. Those two you pictured, I believe, are for the cold start injector and I think EGR.

 

The small connector in front of the green one in the picture. That's the temp gauge.

 

Thank you Kolton. I just tried disconnecting each separately, including the single wire connector you mentioned which is located close to the other two sensors I pictured. Each time, I turned on the key and that dash temp gauge goes right up to just below 50% as always. Now I'm stumped. You'd think that disconnecting the correct one would have disabled the dash gauge.... right?? What the heck is telling that gauge to respond? It could be possessed I guess, or getting it's information from somewhere else.
Should I install my new sensor into that single wire sensor then? I'm puzzled.

 

I removed the single wire sensor only to find that the 'Bosch Universal Temp Gauge' sensor probe is too long for the Toyota housing.



Here is the solution I'm now going to go with... a temp sensor housing that splices into the radiator hose. I'm not sure which diameter I need but I think it's a great solution:

 

Sounds like the gauge is bad. The wire from the sender to the gauge could be shorted somewhere but that will usually pin the gauge if its shorted to ground.

 

Also someone please correct me if I'm wrong, but I believe that sensor grounds through its body, meaning the threads. The threads on that sure look corroded/dirty. I'd try cleaning them as well as the part that it threads into and see if that changes anything

 

Good call and I think you're right about the ground. I'll pop that out again and clean it when I install the hose-splice adapter for the new gauge. I think it'll be here on Friday so I'll get in there again next week.

 

Let us know how it all turns out! My 87 22re 4runner was throwing a knock sensor code, so I pulled the tire and found it was barely finger tight, I pulled it and cleaned the threads reinstalled and no more codes (knock on wood)

 

Time for a follow-up on this thread. I have successfully installed an Auto Meter aftermarket water temp gauge & sensor using a sensor housing that splices into the upper radiator hose. This completely bypasses the factory gauge & sensor which still remain in place. HAPPY!

 

Love the nitrous knob!

 

It is important to maintain a sense of humor with this truck.

 

Yeah, it's not like they're real trucks ... Right ?