Questions about gauges
Senior Member
Joined: Mar 2002
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From: NH
I could go into more detail about how electrical and mechanical gauges work but why not take the word of one of the leading vendors in electrical and mechanical gauges. This is from Autometer’s site:
Now, Autometer sales both mechanical and electrical gauges and their mechanical gauges are usually more then just a few dollars more then their electrical. Therefore, if Autometer was concerned about making the most money you would think they would be a bit biased towards mechanical gauges, or state they, mechanical gauges, are a bit more, or more accurate then electrical.
Mechanical gauges being “more” accurate then electrical is nothing more then a myth now days. It was true in the 60’s and 70’s but not today.
I will say the one disadvantage of electrical gauges is if you have a bad battery and/or a bad alternator your electrical gauges will not read accurately since they are dependant on a constant and correct voltage, otherwise it is simply a users choice of the type of gauge they wish to use with accuracy not being a concern…
A disadvantage of mechanical gauges is you have to have an independent gauge for each and every item you wish to view. You can NOT have one gauge read 3 different items such as water, oil, and transmission temperatures with a simple flip of the switch…
We receive many questions asking which is better, electrical or mechanical gauges. Both mechanical and electrical gauges are equally accurate. The determining factors more involve installation and application than gauge accuracy. Our new "Full Sweep" electric gauges combine the electric gauge wiring with a full sweep dial face like the mechanical gauge.
Mechanical gauges being “more” accurate then electrical is nothing more then a myth now days. It was true in the 60’s and 70’s but not today.
I will say the one disadvantage of electrical gauges is if you have a bad battery and/or a bad alternator your electrical gauges will not read accurately since they are dependant on a constant and correct voltage, otherwise it is simply a users choice of the type of gauge they wish to use with accuracy not being a concern…
A disadvantage of mechanical gauges is you have to have an independent gauge for each and every item you wish to view. You can NOT have one gauge read 3 different items such as water, oil, and transmission temperatures with a simple flip of the switch…
Last edited by 01 XLT Sport; Feb 20, 2005 at 09:09 PM.
Senior Member
Joined: Dec 2004
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From: Lost some where in the middle of the Ozark Mountains!
Yes you will hear arguments from old school about the differences.. Back in the day they would be right...On older vehicles equiped with 40-50 amp (if your lucky) alternators, with electrical gauges you could turn on the headlights and watch all of your electrical gauges drop a few degrees on the sweep...There just wasn't enough juice to run them and the engine and radio and lights all at the same time. Now a days our stock alternators are cranking out 140-200 amps depending up on the vehicle....Either case thats not a problem anymore...
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Joined: Dec 2002
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From: Eastern TN
I could not agree with you more. I was being a wise-guy because of a certain member here who wore me out debating about whether or not electrical gauges are as accurate as mechanical gauges several years ago.
I would venture to say that, in this price range, the accuracy of either is about the same. The interesting part is that the dead-on accuracy is not nearly as important as knowing where the "proper" range is for your given application, but that was never brought up. All that was said is that he knew SOOOOO MANY people who took their crappy electrical gauges back because they were so inaccurate, so that means all of us have inaccurate gauges.
I find it very interesting that many of the folks on this board have electrical and mechanical gauges installed, and when someone asks something like "What temps do you see in the summer in your tranny?" that there are LOTS of folks giving the exact same temperature readings / ranges. Wonder how that happens ???
Nice to see someone with a grip on "gauge reality" !!
I would venture to say that, in this price range, the accuracy of either is about the same. The interesting part is that the dead-on accuracy is not nearly as important as knowing where the "proper" range is for your given application, but that was never brought up. All that was said is that he knew SOOOOO MANY people who took their crappy electrical gauges back because they were so inaccurate, so that means all of us have inaccurate gauges.
I find it very interesting that many of the folks on this board have electrical and mechanical gauges installed, and when someone asks something like "What temps do you see in the summer in your tranny?" that there are LOTS of folks giving the exact same temperature readings / ranges. Wonder how that happens ???
Nice to see someone with a grip on "gauge reality" !!
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Joined: Dec 2004
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From: Lost some where in the middle of the Ozark Mountains!
I knew you were and I think 01 did too...I was just heading it off at the pass! 
Like I said on his old car he would be right but since most of us here are talking about and working on late model trucks then it is not.
Please please no one should be counting how many lines between marks thier needle is sitting while they are driving down the road!!! An analog temp gauge for example +/- 5 degrees is more than accurate for reading while driving! If some one is looking at an analog gauge close enough to be with in 2.5 degrees one way or the other then they are NOT concentrating on driving! They should get a digital ...Opps.. They are electrical, so if they feel electrical is not accurate. Then I guess they would be out of luck for accureacy all together.. huh?
Like I said on his old car he would be right but since most of us here are talking about and working on late model trucks then it is not.
Please please no one should be counting how many lines between marks thier needle is sitting while they are driving down the road!!! An analog temp gauge for example +/- 5 degrees is more than accurate for reading while driving! If some one is looking at an analog gauge close enough to be with in 2.5 degrees one way or the other then they are NOT concentrating on driving! They should get a digital ...Opps.. They are electrical, so if they feel electrical is not accurate. Then I guess they would be out of luck for accureacy all together.. huh?
Senior Member
Joined: Mar 2002
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From: NH
B-Man,
I knew you were kidding with me and as PSS-Mag stated I posted to head off any controversy over electrical vs. mechanical. Basically anyone that has actually researched the subject and/or has a background in electrical gauges would not argue the point.
Now, I will mention that sometimes those arguing over the accuracy of electrical vs. mechanical just have a misunderstanding. Before Autometer started making 270 degree sweep gauges it was exclusive to mechanical gauges.
It can be accurately stated that a mechanical gauge with a 270 degree sweep can be more “accurately” read compared to a 90 degree sweep that electrical gauges have. That means if you had a temperature of say 205 you would most likely be able to read it as 205 on a mechanical because of the longer sweep, whereas on an electrical gauge it might be between 195 mark and 210 and you would basically be able to guess it was approx. 205.
Now, just because a mechanical gauge with a 270 degree sweep can be more accurately read compared to a 90 degree sweep electrical does NOT make it a more accurate gauge.
There is no need for even someone drag racing on the weekends to need to know down to 2 or 3 degrees of accuracy what a temperature is. It doesn’t really matter since they wouldn’t be able to do anything about it anyway.
NASCAR drivers don’t even need to know what the temperature is down to 2 or 3 degrees, they simply need to know what the temperature is within a range of +/- 5 to 10 degrees. Basically they need to know if the temperature is steady or climbing. If it continues to climb above what is considered normal they know they have a problem and it don’t matter if the temperature is 240 degrees or 243 degrees, they are overheating and that is the problem…
There really is nothing to argue about but hey I am always up for a good argument
backed up with some data, facts and professional opinions. So far I have Autometer on my side, and its not the only source…
I knew you were kidding with me and as PSS-Mag stated I posted to head off any controversy over electrical vs. mechanical. Basically anyone that has actually researched the subject and/or has a background in electrical gauges would not argue the point.
Now, I will mention that sometimes those arguing over the accuracy of electrical vs. mechanical just have a misunderstanding. Before Autometer started making 270 degree sweep gauges it was exclusive to mechanical gauges.
It can be accurately stated that a mechanical gauge with a 270 degree sweep can be more “accurately” read compared to a 90 degree sweep that electrical gauges have. That means if you had a temperature of say 205 you would most likely be able to read it as 205 on a mechanical because of the longer sweep, whereas on an electrical gauge it might be between 195 mark and 210 and you would basically be able to guess it was approx. 205.
Now, just because a mechanical gauge with a 270 degree sweep can be more accurately read compared to a 90 degree sweep electrical does NOT make it a more accurate gauge.
There is no need for even someone drag racing on the weekends to need to know down to 2 or 3 degrees of accuracy what a temperature is. It doesn’t really matter since they wouldn’t be able to do anything about it anyway.
NASCAR drivers don’t even need to know what the temperature is down to 2 or 3 degrees, they simply need to know what the temperature is within a range of +/- 5 to 10 degrees. Basically they need to know if the temperature is steady or climbing. If it continues to climb above what is considered normal they know they have a problem and it don’t matter if the temperature is 240 degrees or 243 degrees, they are overheating and that is the problem…
There really is nothing to argue about but hey I am always up for a good argument
backed up with some data, facts and professional opinions. So far I have Autometer on my side, and its not the only source…
Senior Member
Joined: Dec 2004
Posts: 891
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From: Lost some where in the middle of the Ozark Mountains!
I have one vehicle with a few digital gauges and they are nice except the slightest fluctuation and it registers. The rest of my vehciles are exlusivley electrical analog. Like 01 XLT Sport said as long as I know that it is stable then I am happy..If it's not stable I want to know if the componet it is in a safe operating range or not so I know whether I should continue on the road and try to drive it back to the house. Or pull over and call a wrecker.
It would be nice if we all were like the nascar drivers and had a pit crew to watch our gauges from the pits and let us know if we need to run harder take it easy or pull in to get a problem checked out!
Just think if that happens maybe atleast one guy will be saved from the call that his wife didn't check her oil and is now having it towed back to the house because it locked up! 
It would be nice if we all were like the nascar drivers and had a pit crew to watch our gauges from the pits and let us know if we need to run harder take it easy or pull in to get a problem checked out!
Hommmme.. Hommme...
NosturPSS predicts that......In a few years northstar will beable to do this for us and we will not even have to look at our gas gauge! When gas runs low they will come over the NS speaker and let us know that we need to get gas soon and how many miles +/- a .1 of a mile you have left before you run out! If there is a fluctuation in another monitored system then they will call us again to let us know and offer advise as to what actions we should take.
Hommmme....
NosturPSS predicts that......In a few years northstar will beable to do this for us and we will not even have to look at our gas gauge! When gas runs low they will come over the NS speaker and let us know that we need to get gas soon and how many miles +/- a .1 of a mile you have left before you run out! If there is a fluctuation in another monitored system then they will call us again to let us know and offer advise as to what actions we should take.
Hommmme....
Last edited by PSS-Mag; Feb 21, 2005 at 01:17 AM.
Senior Member
Joined: Sep 2002
Posts: 2,165
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From: Cabot, AR
Howdy ya'll,
I also am planning on installing extra gauges in my truck. Currently I plan on using a Lo-tek single gauge pod so that I can keep my grab handle, with single temp gauge monitoring water and trans temp. I plan on adding an extra twist, adding led lights to indicate which temp the gauge is monitoring. I will cut holes in the area between the gauge and A-pillar and make up a black label with the letters TRANS and WATER cut out. I will have green LEDs mounted behind the label. By using a DPDT switch the indicator light and gauge will operate off of the same switch. I will have a relay mounted on the indication circuit so that I will have bright lights when the headlights are on and the LEDs will dim in proportion to the rest of the interior lights.
Also on the subject of gauges, Defi makes 270° sweep electrical gauges I plan on using one of these. Their temp gauges only says temp, not water temp or trans temp like the other gauges do. All of this has not been done yet, but I plan on doing this soon. If anyone is interested I will post a simple schematic and list of part numbers.
Joe
I also am planning on installing extra gauges in my truck. Currently I plan on using a Lo-tek single gauge pod so that I can keep my grab handle, with single temp gauge monitoring water and trans temp. I plan on adding an extra twist, adding led lights to indicate which temp the gauge is monitoring. I will cut holes in the area between the gauge and A-pillar and make up a black label with the letters TRANS and WATER cut out. I will have green LEDs mounted behind the label. By using a DPDT switch the indicator light and gauge will operate off of the same switch. I will have a relay mounted on the indication circuit so that I will have bright lights when the headlights are on and the LEDs will dim in proportion to the rest of the interior lights.
Also on the subject of gauges, Defi makes 270° sweep electrical gauges I plan on using one of these. Their temp gauges only says temp, not water temp or trans temp like the other gauges do. All of this has not been done yet, but I plan on doing this soon. If anyone is interested I will post a simple schematic and list of part numbers.
Joe
Member
Joined: Jan 2005
Posts: 91
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From: Texas
I got a technical question on this matter. I have a 2000 F150 v6 with the 5spd and the cluster dosen't have a tac, I was wondering if anyone knew if I swap clusters with one that does have a tac, does my F150's comp send a tac signal to the cluster or would it just be a dead gauge?
Senior Member
Joined: Sep 2002
Posts: 2,165
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From: Cabot, AR
Here is a schematic that I have drawn up. So far it is not that pretty, but if you have questions I will try to answer them.
Here is a partial parts list, there are a few more items that might be added and I might test some of the parts before the final install. If there is intrest I will keep ya'll posted. However, the final product might be some time in the making.
Green LED $1.99 x2
Radio Shack Cat No 276-271
DPDT Rocker Switch $3.99 x1
Radio Shack Cat No 275-695
SPDT Micro Relay $4.29 x1
Radio Shack Cat No 275-241
Relay socket
Fuse block (TBD)
Gauge your choice
Senders to match gauge
Gauge pod
Wire
Wire splices, wrap, ties, electrical tape, shrink tubing, etc.
If you have any questions I will try to answer them as best as I can.
Joe
Here is a partial parts list, there are a few more items that might be added and I might test some of the parts before the final install. If there is intrest I will keep ya'll posted. However, the final product might be some time in the making.
Green LED $1.99 x2
Radio Shack Cat No 276-271
DPDT Rocker Switch $3.99 x1
Radio Shack Cat No 275-695
SPDT Micro Relay $4.29 x1
Radio Shack Cat No 275-241
Relay socket
Fuse block (TBD)
Gauge your choice
Senders to match gauge
Gauge pod
Wire
Wire splices, wrap, ties, electrical tape, shrink tubing, etc.
If you have any questions I will try to answer them as best as I can.
Joe