Water Temp Sending Unit Questions?

[ninety15.0]

Hey guys...I've pretty much finished up doing all the electrical wiring to install my 3 gauges on the A-pilar. I followed the basic directions from srothfuss' install and it looks real clean and solid. Im going to make all the connections to the car tommorrow, but i have a question or two. One of my gauges is a 2 5/8" AM elec. water temp and i recieved a sending unit with the gauge, my question is where does that sending unit go? Do you need to drill and tap a hole in the rad or something or does it replace the stock sensor in the front of the Lower int. man? Secondly i got a mechanical boost gauge and it came with a T-fitting to tie into an existing vac line. Which vac line is the easiest to T into? It seems like the T is designed for a larger vac line than the ones used for EGR and FPR...but its not quite big enough for a Brake Booster line? Also what has anyone done to protect that nylon tubing...that wire loom crap? Any help or experience would be greatly appreciated! thanks!
-Nick

 

[vristang]

I would put the temp sending unit in the stock location. If you want to keep the stock gauge functional, then you may find another mounting location already drilled and tapped in the back corners of the lower intake.

I tapped into the vac tree for my vac/boost gauge.

jason

 

[ninety15.0]

I have always been under the impression that the ECT sensor did more than just run the temp gauge. I thought the computer adjusted timing and whatnot depending on Engine Temp?!?!? IF this were the case wouldnt deactivating the stock sensor and wiring cause issues?! Im all for just tossing that new sending unit in the manifold because its a quick and easy solution but if its going to cause any problems then i would rather mount it in another location. Just so we are talkin bout the same sensor...im refering to the sensor thats on the front left part of the lower intake (if your sitting in the drivers seat)...and it has one single wire sitting on the top of it? Thanks in advance.

 

[vristang]

There are 2 cooling system temp sensors.
The ECT sends a signal to the computer, and the computer does use it the way you described. The ECT is located on the Heater tube on the passenger side of the lower intake, just forward of the TB.
The temp gauge has its own sensor on the drivers side, which threads directly into the lower manifold. Removing this sensor will not affect the motor in any way. It will just kill the stock temp gauge.

jason

 

[HISSIN50]

The single wire sender behind the dizzy is for the gauge (and only for the gauge). The ECT is a multi-wire sensor on the pass side heater pipe.

I would (and did) also relocate the stock sender (the stock location is very accurate so you want the best gauge there). On the fox I had a dead port on the driver side back of the lower intake - my stock sender went there.
On the 5N95, there was no dead port so I got a cast t-stat housing from the parts store (10 bucks) and used the tapped hole in it for the stock sender. These housings do rust. FRPP chrome housings are an alternative, but some prep should be done to avoid leaks.

Good luck.

EDIT: Jason posted while I was pecking.

 

[onefstsnake]

could you run wires from both the AM gauge and the stock gauge to 1 sending unit? and would they be accurate?

Ive always thought about doing this, since I hate having a dead gauge.

Im guessing if it didnt work each gauge would read half of the actual temp.

 

[HISSIN50]

could you run wires from both the AM gauge and the stock gauge to 1 sending unit? and would they be accurate?

Ive always thought about doing this, since I hate having a dead gauge.

Im guessing if it didnt work each gauge would read half of the actual temp.

You're right - it wont work. If both gauges were calibrated the same (they arent) then you could try and extrapolate a reading. But with different calibrations, you'd just have two useless gauges.

In the same vein, using a tee fitting for temperature gauges is not a good idea (the coolant pools in the alcove of the tee and the coolant in there kinda gets heated radiantly).

 

[onefstsnake]

yeah I was pretty sure it wouldnt work, since I havent seen/heard anyone doing this. Maybe ill put the stock sensor in the rear of the intake when I swap Intake Manifolds.

 

[ninety15.0]

Thanks guys...thats kinda what i figured. Dont know what i was thinkin. I appreciate the help!