Using 2 different Coolant temp sensors at same time

[jayfire]

I have a new Holley Sniper FI unit going on my car soon, and it uses its own temp sensor going into the water pump. I am also installing the Dakota Digital gauge cluster as well. It comes with its own temp sensor. Can I just install one sensor and tap the wires for the gauges and FI unit or should I install both sensors and run wiring separately? Thanks

 

[pnora]

No. They each need to be separate and do their own function. You tie them together or mix them up your troubles will begin.

 

[LowBikeMike]

It would be interesting to see if they are calibrated the same, if they are, I can see where runnnig 1 sensor would work. Take an ohmeter and measure the resistance from the electrical terminal to the sensor threads on both sensors, is the reading the same at room temperature? Is so, heat the probes to the same temp and measure resistance again. If their resistance is the same at both temperatures, I'd try to run just one, if not, I agree with Pnora.

 

[440SportSatellite]

I'm running separate sensors for my Sniper and my Dakota Digital gauges. Pretty sure the DD sensor is only available from them. I know this because I overtightened and snapped off the original that came with the gauge cluster. They were nice enough to send me the replacement free of charge as a warranty item, even though it was my mistake. It's possible they use the same ohm readings, but it was just easier to run both sensors since I had a spot for both of them in the water pump housing.
FYI, the sensor that came with my Sniper read about 10-15 degrees cooler than the actual coolant temperature. Bought a replacement from autozone for a few bucks and it reads spot on.

 

[RJRENTON]

I have a new Holley Sniper FI unit going on my car soon, and it uses its own temp sensor going into the water pump. I am also installing the Dakota Digital gauge cluster as well. It comes with its own temp sensor. Can I just install one sensor and tap the wires for the gauges and FI unit or should I install both sensors and run wiring separately? Thanks

ABSOLUTELY NOT....The origional Mopar temp sensor was designed to operate the instrument panel gauge. Its a PTC device (Positive Temperature Coefficient) with a specific ohmic value. Do you know what type and value the device used with the Dakota and Holley system uses? Because of the digital nature of those devices and their systems the components they use, it is likely that they are ANALOG devices with specific scaling, and will have different values and calibration points, providing different results. Install the respective sensors EXACTLY as directed by the installation documentation independent of each other. Just my opinion of course.
BOB RENTON

 

[2quick]

Tried this already with F.A.S.T EFI and a Racepak Dash (does not work) Had to run two independent sensors.

 

[Slap Stick]

Ma MoPar uses two. One for the ECU and one for the temp gauge.

 

[493 Mike]

Different circumstance similar thought. I am using a Autometer coolant temp gauge with 2 sensors and a DTDP switch. One in the water pump housing and the second in the transmission pan.
Mike

 

[bm02tj]

A lot of electronic devices use 10k Thermistors
Down load a chart and test them

 

[moparedtn]

Just run them separately per instructions and be done with it, avoiding any potential issues
in doing so...

 

[RJRENTON]

A lot of electronic devices use 10k Thermistors
Down load a chart and test them

But just as many electronic devices use 100 ohm platinum 3 wire RTD devices, which are far more accurate and yield faster response time.....just sonething to consider.
BOB RENTON

 

[jayfire]

I'm running separate sensors for my Sniper and my Dakota Digital gauges. Pretty sure the DD sensor is only available from them. I know this because I overtightened and snapped off the original that came with the gauge cluster. They were nice enough to send me the replacement free of charge as a warranty item, even though it was my mistake. It's possible they use the same ohm readings, but it was just easier to run both sensors since I had a spot for both of them in the water pump housing.
FYI, the sensor that came with my Sniper read about 10-15 degrees cooler than the actual coolant temperature. Bought a replacement from autozone for a few bucks and it reads spot on.

Do you know what size the Dakota Digital temp sensor is? My water pump has 4 holes. 2 for heater hoses, a 1/2" hole reduced to 3/8" for the Sniper sensor, then there's the small 1/8" hole. Its a 426 Hemi with a 6-71 blower. I don't think I have enough room under the blower to add an extension with a port under the water neck. Thanks

 

[440SportSatellite]

Do you know what size the Dakota Digital temp sensor is? My water pump has 4 holes. 2 for heater hoses, a 1/2" hole reduced to 3/8" for the Sniper sensor, then there's the small 1/8" hole. Its a 426 Hemi with a 6-71 blower. I don't think I have enough room under the blower to add an extension with a port under the water neck. Thanks

I'm fairly certain that it has 1/8" NPT threads, so it will probably fit in the stock sensor location. The water pump housing on my 440 has 2 extra outlets at the top in addition to the outlets for the stock sensor and the heater hoses, so I just used those with an adapter bushing as they were easier to get to.
It's been a year since I installed it though, so I could be remembering the size wrong.

 

[kordoy]

Doesn't Dakota Digital have an add-on module to read the data off of the Sniper to actuate the temp gauge?

 

[440SportSatellite]

Doesn't Dakota Digital have an add-on module to read the data off of the Sniper to actuate the temp gauge?

They do have an add on module that reads sniper data, it only displays on the screen in the cluster though and won't send a signal to the temp gauge. At least that's the way it was when I installed mine a year ago, they may have upgraded that feature since then.