question about water temp gauges
Thread Starter
Full Member
Joined: Dec 2002
Posts: 221
Likes: 0
From: olympia WA.
question about water temp gauges
Im curious if you can run more then one gauge off the stock water tmep sender? ex- water is being displayed on my pfc, can i hook up a second gauge? and will it read ok it's a cyberdyne digital gauge.
Wishin I Still Had The FD
Joined: Sep 2005
Posts: 1,420
Likes: 1
From: Las Vegas, NV
I don't really understand why you would want to do that. If anything, run the gauge with an independent sensor, that way you have a source to cross-reference your temps from.
-Scott
-Scott
Thread Starter
Full Member
Joined: Dec 2002
Posts: 221
Likes: 0
From: olympia WA.
the problem is, i run evans coolent and a custom v-mount = no way do drain the coolent with out making a total mess! is there some place by the coolent filler neck to put the sender?
2? if i unplug the stock sender to use my cyberdyne will the ecu have a problem ?
2? if i unplug the stock sender to use my cyberdyne will the ecu have a problem ?
Trending Topics
If you wanna run a aftermarket sensor just tap into the filler neck, seems like a popular spot and keep the stock sensor connected. Like Vegas said it would be nice to cross referance to see how accurate your stock gauge is.
Wishin I Still Had The FD
Joined: Sep 2005
Posts: 1,420
Likes: 1
From: Las Vegas, NV
Just kidding.
Thread Starter
Full Member
Joined: Dec 2002
Posts: 221
Likes: 0
From: olympia WA.
well im not using the stock gauge im using the commander and it reads in celius, thats why i want another gauge, just want to know if i had to, can both gauges run off that sender. it would be nice to have two differant senders in two differant locations, but thats not my goal at the moment
Scott
Scott
Senior Member
Joined: Jul 2004
Posts: 392
Likes: 0
From: Australia
pfc does not give you accurate temps of the 'system', only engine temps.
this is what is happening to me atm.
start the car, pfc rises, greddy stays. When pfc hits 70ish after 10mins (slow cruising) the greddy will start rising slowly. it will take the greddy 10mins or so to hit 80 and be the same as the pfc.
start stop traffic they will both be the same but once as you get out onto the open road (especialy at night) the pfc will go down to 85 and the greddy will go down to (75-80).
this is what is happening to me atm.
start the car, pfc rises, greddy stays. When pfc hits 70ish after 10mins (slow cruising) the greddy will start rising slowly. it will take the greddy 10mins or so to hit 80 and be the same as the pfc.
start stop traffic they will both be the same but once as you get out onto the open road (especialy at night) the pfc will go down to 85 and the greddy will go down to (75-80).
------->
OK, got some pics of the brass T I used. I got all this stuff from Lowe's. Can't remember total cost - probably $5-10 or so.
Parts I used -
Brass T with 1/4" NPT ports
2 1/4" NPT hose barbs with (I think) 5/16" hose barbs. The hose barbs were just the size that fit on the TB hoses - I just eyeballed it. The only other sizes were obviously too big or too small.
1/4" NPT to 1/8" NPT adapter/bushing.
As you can see in the pics, teflon tape up the fittings and screw it together. I used the 1/4" NPT to 1/8" NPT adapter to space the water temp sensor up and away. If I would have used a 1/8" NPT brass tee, the tip of the sensor would have interfered with the opposite side of the tee - best case it would have touched the brass and possibly give a false reading, worst case it wouldn't screw in enough to make a watertight seal at the threads.
BTW, all the Japanese temp sensors are 1/8" NPT - I'm not sure what Autometer is, I'm guessing 3/8" NPT. You're on your own there.
Dale
Parts I used -
Brass T with 1/4" NPT ports
2 1/4" NPT hose barbs with (I think) 5/16" hose barbs. The hose barbs were just the size that fit on the TB hoses - I just eyeballed it
. The only other sizes were obviously too big or too small.1/4" NPT to 1/8" NPT adapter/bushing.
As you can see in the pics, teflon tape up the fittings and screw it together. I used the 1/4" NPT to 1/8" NPT adapter to space the water temp sensor up and away. If I would have used a 1/8" NPT brass tee, the tip of the sensor would have interfered with the opposite side of the tee - best case it would have touched the brass and possibly give a false reading, worst case it wouldn't screw in enough to make a watertight seal at the threads.
BTW, all the Japanese temp sensors are 1/8" NPT - I'm not sure what Autometer is, I'm guessing 3/8" NPT. You're on your own there
.Dale
Last edited by Sgtblue; Jul 31, 2007 at 07:53 PM.
Senior Member
Joined: Oct 2002
Posts: 526
Likes: 5
From: Atlanta
Incorrect information! While it's true you can turn the fans on at whatever temperature you choose (low speed without A/C or medium speed with A/C) with aftermarket ECU (Apexi PFC for sure, I don't know about others), the fans will not go into high speed (or medium w/o A/C) until the thermoswitch is triggered. Unless you do a manual switch override you need to replace the stock thermoswitch with the 97 degree switch if you want high fan speed under 108 degrees.
Incorrect information! While it's true you can turn the fans on at whatever temperature you choose (low speed without A/C or medium speed with A/C) with aftermarket ECU (Apexi PFC for sure, I don't know about others), the fans will not go into high speed (or medium w/o A/C) until the thermoswitch is triggered. Unless you do a manual switch override you need to replace the stock thermoswitch with the 97 degree switch if you want high fan speed under 108 degrees.
pfc does not give you accurate temps of the 'system', only engine temps.
this is what is happening to me atm.
start the car, pfc rises, greddy stays. When pfc hits 70ish after 10mins (slow cruising) the greddy will start rising slowly. it will take the greddy 10mins or so to hit 80 and be the same as the pfc.
start stop traffic they will both be the same but once as you get out onto the open road (especialy at night) the pfc will go down to 85 and the greddy will go down to (75-80).
this is what is happening to me atm.
start the car, pfc rises, greddy stays. When pfc hits 70ish after 10mins (slow cruising) the greddy will start rising slowly. it will take the greddy 10mins or so to hit 80 and be the same as the pfc.
start stop traffic they will both be the same but once as you get out onto the open road (especialy at night) the pfc will go down to 85 and the greddy will go down to (75-80).
For the newbies posting in this thread, you really should take the time to read about all of the documented FACTS about the cooling system. Links to them are in the FAQ thread stickied here in this forum.
+1 on the TB Coolant line for a second water temp. sensor (assuming you haven't bypassed the TB coolant line). There are a few very nice write ups on how to do it on the forum. It is ridiculously easy, cheap (assuming you have already purchased the gauge), and provides you with yet another independent temp. reading. I'm about as unskilled in the garage as it gets and I was able to install the temp sensor there in no time, with no draining of the coolant. My .02 cents anyway...
Senior Member
Joined: Jul 2004
Posts: 392
Likes: 0
From: Australia
Sorry but that is just wrong. With the sender in the location you mentioned, the PFC is absolutely correct. It uses the factory water temp sensor.
For the newbies posting in this thread, you really should take the time to read about all of the documented FACTS about the cooling system. Links to them are in the FAQ thread stickied here in this forum.
For the newbies posting in this thread, you really should take the time to read about all of the documented FACTS about the cooling system. Links to them are in the FAQ thread stickied here in this forum.
Joined: Feb 2002
Posts: 1,171
Likes: 0
From: MI
Preface: I realize this is an older thread 
... Just thought I'd add to it because noone ever answered the OP's original question...
Yes, you can tap into existing sensors, but as previously mentioned a lot of people don't see the point because it's the same reading twice...
The gauge pack I have installed in my truck uses this method for an easy installation, just taps into the existing temp sensor and it works GREAT, simple install too.
... Just thought I'd add to it because noone ever answered the OP's original question...well im not using the stock gauge im using the commander and it reads in celius, thats why i want another gauge, just want to know if i had to, can both gauges run off that sender. it would be nice to have two differant senders in two differant locations, but thats not my goal at the moment
Scott
Scott
The gauge pack I have installed in my truck uses this method for an easy installation, just taps into the existing temp sensor and it works GREAT, simple install too.
Tapping into the stock water sensor to try to use it with an aftermarket gauge will not work since the gauge is calibrated for its own sensor. For example, you can't use a Greddy, HKS, Apexi or Autometer gauge with the factory Mazda sensor unless the gauge was calibrated to get readings off of that sensor. Hope this makes sense. You'd need to use your aftermarket's temp sender in a different place, ie. TB line, thermostat housing or via one of those radiator hose adapters.
Joined: Feb 2002
Posts: 1,171
Likes: 0
From: MI
To my knowledge a water temp gauge/sensor are about as simple as they get, the heat transferred to the sensor translates into a voltage which the gauge spits back out as a temperature reading.
Not that I'm an expert, but I've seen this done on a few occasions and it's worked, might have either been dumb luck or a lot more of these companies are "calibrated" the same but again I never thought temp gauges were quite that sophisticated. Also I am currently using the factory temp sensor on my truck to run my aftermarket gauge, spliced right into the factory harness, haven't had any issues to date.
Not that I'm an expert, but I've seen this done on a few occasions and it's worked, might have either been dumb luck or a lot more of these companies are "calibrated" the same but again I never thought temp gauges were quite that sophisticated. Also I am currently using the factory temp sensor on my truck to run my aftermarket gauge, spliced right into the factory harness, haven't had any issues to date.
Senior Member
Joined: Nov 2006
Posts: 731
Likes: 0
From: Dallas TX
If you try to run two gauges off one sender I would think you would have problems with each gauge measuring not only the resistance of the sender but also the resistance path back through the other gauge. You might be able to solve this with diodes but I'm no EE so I don't know if diodes would solve that problem (or even if it is a problem)
You could wire an SPDT switch in and toggle back and forth between gauges without a problem. I don't know if that solution works for you as you wouldn't be able to read both gauges at the same time.
Joined: Feb 2002
Posts: 1,171
Likes: 0
From: MI
Well I don't get any interference between the two gauges I have running off the stock sensor in my truck. The factory gauge reads exactly like it did before installing the other, and the aftermarket gauge reads the temperature that it should be.
The only reason I see this NOT working is because there is something different about the sensor/gauge in the FD that I'm overlooking, because it works fine in my truck and a few other cars I've seen installed like that.
The only reason I see this NOT working is because there is something different about the sensor/gauge in the FD that I'm overlooking, because it works fine in my truck and a few other cars I've seen installed like that.
Thread
Thread Starter
Forum
Replies
Last Post
sherff
Adaptronic Engine Mgmt - AUS
9
Feb 24, 2019 12:09 PM
befarrer
Microtech
3
Aug 22, 2015 05:52 PM
