Stinkin temp gauge

[chicofuentes0224]

Well I changed my temp gauge today with one that was recalibrated hoping that it would read somewhere close to 210* because that's what my engine is running at.

However after swapping it out it still reads close to the red zone.

Couple things.

1)This is the third gauge I've tried. All read at the same spot.

2)The temp sender on the back of the head has been replaced twice with brand new ones from NAPA.

3)The engine is not running as hot as the gauges have said. This has been verified with at least ten differnt laser thermometers by checking the thermostat housing and the temp right where the sensor goes into the back of the head. Both spots have always been under 210*

So what are my options?

 

1)Try changing the temp sensor again with a differnt one from let's say Autozone or the dealer.

2)Try screwing with the needle on the gauge to get it at around 210* when the engine is hot. (Does anyone know how to do this because I tried but couldn't figure out how to "adjust" the needle.)

3)Live with the fact that the engine temp is great (thank the Gods) and that any stinkin gauge I put in will always run extremely close to the RED ZONE, because this God forsaken truck has about One million electrical problems. (I'm really not as upset as I sound, just frustrated that the darn thing doesn't work like it should.)

 

Or does anyone else have any bright ideas?

And NO, lighting the truck on fire is not an option. :brows:

[87ComancheLB]

Why does your truck have a million electrical problems? If you replaced both items then it has to be in the interface between the sensor to the gauge, sounds like a open loop or grounding issue.

[chicofuentes0224]

Why does your truck have a million electrical problems? If you replaced both items then it has to be in the interface between the sensor to the gauge, sounds like a open loop or grounding issue.

 

Actually it's not a million, (probably like only two left :oops: ) Sorry, I have a knack for being dramatical. So, any idea on how I would go about checking for open loops or grounding issues. I'm sorry, I'm electrically illeterate.

 

Edit: And a horrible speller. :D

[87ComancheLB]

I guess I would checked the harness etc if you have a multimeter you can ohm out the wires, is there a PDF file for the electrical schematics somewhere online? it would help trace it back into the firewall and under the dash or try turning it on and grab some wires underneath wiggle them around to see if it moves the needle if it does then you might have a intermittant problem could also be a pin contact problem in a connector not making good contact etc.

[HOrnbrod]

Well I changed my temp gauge today with one that was recalibrated hoping that it would read somewhere close to 210* because that's what my engine is running at.

However after swapping it out it still reads close to the red zone.

Couple things.

1)This is the third gauge I've tried. All read at the same spot.

2)The temp sender on the back of the head has been replaced twice with brand new ones from NAPA.

3)The engine is not running as hot as the gauges have said. This has been verified with at least ten differnt laser thermometers by checking the thermostat housing and the temp right where the sensor goes into the back of the head. Both spots have always been under 210*

So what are my options?

 

1)Try changing the temp sensor again with a differnt one from let's say Autozone or the dealer.

2)Try screwing with the needle on the gauge to get it at around 210* when the engine is hot. (Does anyone know how to do this because I tried but couldn't figure out how to "adjust" the needle.)

3)Live with the fact that the engine temp is great (thank the Gods) and that any stinkin gauge I put in will always run extremely close to the RED ZONE, because this God forsaken truck has about One million electrical problems. (I'm really not as upset as I sound, just frustrated that the darn thing doesn't work like it should.)

 

Or does anyone else have any bright ideas?

And NO, lighting the truck on fire is not an option. :brows:

 

Well, I know for a fact that the last gauge you put in was calibrated correctly. :chillin: Here's what you can do. Start your engine up. When the temp gauge indicates 180*, disconnect the wire from the temp thermister and accurately measure the resistance between the thermister tip and ground. Stick the wire back on, and repeat at 210* then at normal running temperature. Let me know what these three resistance readings are. Not going to tell you what they should be so you're not looking for a certain resistance. :D

[mjeff87]

when I swapped the full gauge cluster into mine I decided to clean it up real good...to the point of removing the clear plastic cover on the gauge pod and wiping the micro-dust off of the gauge faces. Well.....apparently the temp gauge needle was a bit loose on the pin and I "bumped" it over a bit to the hot side. When it ran, it was reading 220-230 deg, and I know my engine never ran hot, ever. I verified the temp with a laser temp gauge @ the sending unit location, which was right around 190-200, then just gently nudged the needle back on the cluster until it read the same.

 

I ain't workin' with NASA componentry here..... :D

 

Jeff

[HOrnbrod]

when I swapped the full gauge cluster into mine I decided to clean it up real good...to the point of removing the clear plastic cover on the gauge pod and wiping the micro-dust off of the gauge faces. Well.....apparently the temp gauge needle was a bit loose on the pin and I "bumped" it over a bit to the hot side. When it ran, it was reading 220-230 deg, and I know my engine never ran hot, ever. I verified the temp with a laser temp gauge @ the sending unit location, which was right around 190-200, then just gently nudged the needle back on the cluster until it read the same. I ain't workin' with NASA componentry here..... :D

Jeff

 

What? I thought NASA made these clusters, NASA Japan that is. :eek: Well, it ain't the gauge. He's had three of them and they are all reading consistently. I've noticed also that my laser temp gauge reads about 10* lower than the actual coolant temperature when hitting the outside metal surfaces like temp sensors and thermostat housings. Verified it with an old fashioned mercury thermometer.

[chicofuentes0224]

Well I changed my temp gauge today with one that was recalibrated hoping that it would read somewhere close to 210* because that's what my engine is running at.

However after swapping it out it still reads close to the red zone.

Couple things.

1)This is the third gauge I've tried. All read at the same spot.

2)The temp sender on the back of the head has been replaced twice with brand new ones from NAPA.

3)The engine is not running as hot as the gauges have said. This has been verified with at least ten differnt laser thermometers by checking the thermostat housing and the temp right where the sensor goes into the back of the head. Both spots have always been under 210*

So what are my options?

 

1)Try changing the temp sensor again with a differnt one from let's say Autozone or the dealer.

2)Try screwing with the needle on the gauge to get it at around 210* when the engine is hot. (Does anyone know how to do this because I tried but couldn't figure out how to "adjust" the needle.)

3)Live with the fact that the engine temp is great (thank the Gods) and that any stinkin gauge I put in will always run extremely close to the RED ZONE, because this God forsaken truck has about One million electrical problems. (I'm really not as upset as I sound, just frustrated that the darn thing doesn't work like it should.)

 

Or does anyone else have any bright ideas?

And NO, lighting the truck on fire is not an option. :brows:

 

Well, I know for a fact that the last gauge you put in was calibrated correctly. :chillin: Here's what you can do. Start your engine up. When the temp gauge indicates 180*, disconnect the wire from the temp thermister and accurately measure the resistance between the thermister tip and ground. Stick the wire back on, and repeat at 210* then at normal running temperature. Let me know what these three resistance readings are. Not going to tell you what they should be so you're not looking for a certain resistance. :D

 

Right, I'll get it done probably this weekend or early next week and let you know. Thanks Don.

 

Jeff, I tried pulling the plastic cover off and moving the needle back by hand on an earlier gauge and all it did was move back toward the hot zone. I don't want to mess with the new one because Don has it working correctly for sure.

 

Don, when you say the thermister tip, you mean the wire going to my temp sender on the head right?

[HOrnbrod]

Don, when you say the thermister tip, you mean the wire going to my temp sender on the head right?

 

That's correct Chico.

[chicofuentes0224]

Well I changed my temp gauge today with one that was recalibrated hoping that it would read somewhere close to 210* because that's what my engine is running at.

However after swapping it out it still reads close to the red zone.

Couple things.

1)This is the third gauge I've tried. All read at the same spot.

2)The temp sender on the back of the head has been replaced twice with brand new ones from NAPA.

3)The engine is not running as hot as the gauges have said. This has been verified with at least ten differnt laser thermometers by checking the thermostat housing and the temp right where the sensor goes into the back of the head. Both spots have always been under 210*

So what are my options?

 

1)Try changing the temp sensor again with a differnt one from let's say Autozone or the dealer.

2)Try screwing with the needle on the gauge to get it at around 210* when the engine is hot. (Does anyone know how to do this because I tried but couldn't figure out how to "adjust" the needle.)

3)Live with the fact that the engine temp is great (thank the Gods) and that any stinkin gauge I put in will always run extremely close to the RED ZONE, because this God forsaken truck has about One million electrical problems. (I'm really not as upset as I sound, just frustrated that the darn thing doesn't work like it should.)

 

Or does anyone else have any bright ideas?

And NO, lighting the truck on fire is not an option. :brows:

 

Well, I know for a fact that the last gauge you put in was calibrated correctly. :chillin: Here's what you can do. Start your engine up. When the temp gauge indicates 180*, disconnect the wire from the temp thermister and accurately measure the resistance between the thermister tip and ground. Stick the wire back on, and repeat at 210* then at normal running temperature. Let me know what these three resistance readings are. Not going to tell you what they should be so you're not looking for a certain resistance. :D

 

 

Yeah, uhhh Donnie. I'm getting a big fat 0 at all three temps, am I doing something wrong? You did say to measure the resistance at the wire right, or am I actually suppose to measure the tip of the sensor coming outta the head?

 

Edit: I measured at the tip of the sensor coming outta the head and at running temp it fluctuates between 36 and 47 :nuts:

[HOrnbrod]

Tip of the sensor to ground Chico. What we're doing here is checking out the thermister (temp sender) resistances at various temps thouughout it's range. The resistance should decrease as the temp goes higher. Or you could try a spare sender in a pot of boiling water and monitor it with a thermometer from cold to hot.

[chicofuentes0224]

Ok tip of the sensor was 36 to 47 depending where I stuck the negative to on the ground braid.

[HOrnbrod]

Ok tip of the sensor was 36 to 47 depending where I stuck the negative to on the ground braid.

 

Stick the negative on the sensor brass case; that's the ground conductor. You didn't wrap the threads with an insulator like teflon tape when you installed it did ya?

[HOrnbrod]

Don, when you say the thermister tip, you mean the wire going to my temp sender on the head right?

 

That's correct Chico.

 

This was misleading - my bad. :oops:

[chicofuentes0224]

Ok tip of the sensor was 36 to 47 depending where I stuck the negative to on the ground braid.

 

Stick the negative on the sensor brass case; that's the ground conductor. You didn't wrap the threads with an insulator like teflon tape when you installed it did ya?

 

Nope, didnt use teflon tape.

So to get this staight. At 180 I'm gonna pull the wire. Touch the positive to the tip if the sender and the negative to the brass base?

Then, I'm going to repeat at 210 and at running temp?

Did I get it right?

[chicofuentes0224]

Ok, on the gauge

180* =.205

210* =171.1

running temp =119.5

 

I'll check them again in an hour to make sure I get numbers close to that to make sure I didn't mess it up.

[chicofuentes0224]

Donnie, this was resistance test #2

 

On the gauge

180*=.232

210*=179.1

runing temp=119.5

[HOrnbrod]

Donnie, this was resistance test #2

 

On the gauge

180*=.232

210*=179.1

runing temp=119.5

 

The ohms readings at the various temps should decrease as the temp gauge goes up, so I'm interpreting your 180* reading as 232 ohms; I think you're reading the scale wrong on your ohmeter. :eek: That sensor is going in the right direction, but it's range seems wrong. Factory cal specs are: 100* = 1365 ohms; 220* = 93.5 ohms; 260* = 55.1 ohms.

 

I'd ask Taz to send ya a regulation dealer sensor for it and try that. And have you ohmed out the circuit from the sensor wire to the cluster temp gauge input? You might be picking up some added resistance in the harness somewhere.

[chicofuentes0224]

Yeah I'm gonna have to play with it some more tomorrow. It's too dark now and I can't see a thing a thing. Plus I really don't think I'm reading it correctly. I'm just giving out the numbers that are popping up on the screen.

[chicofuentes0224]

So Don, I was reading the gauge wrong,

 

On the gauge

180*=2320 ohms

210*=179.1 ohms

running temp=119.5 ohms

 

I had it verified by someone who knows what they're doing.

So I guess the sensors are calibrated wrong right?

Like you said, guess I'll get one from Taz.

[HOrnbrod]

So Don, I was reading the gauge wrong,

 

On the gauge

180*=2320 ohms

210*=179.1 ohms

running temp=119.5 ohms

 

I had it verified by someone who knows what they're doing.

So I guess the sensors are calibrated wrong right?

Like you said, guess I'll get one from Taz.

 

I don't know Chico. A running temp reading of 119.5 ohms should return a gauge reading of >220*. Stick an OEM sensor in there and see if it reads okay, it's cheap. If not there's a resistance problem between the sensor and the temp gauge. I've got tons of cluster parts I can send you like new foil p/c backing, etc. but I think it could be in the harness.

[chicofuentes0224]

Yeah, I started playing with this last night again. Changed out the sensor for another one fom Autozone to see if it would make any differnce at all. Nothing. Still reads high.

Don, do you have a whole other cluster with a cable driven speedo I can buy from you. I vaguely remember my temp gauge working correctly on the second cluster I had in there. It's oil gauge was shot but the temp worked right. I made the mistake of letting my two year old work on it with my drill :roll: .

After I change it out if I still get a whacked reading I'll start ripping the harness apart and figuring out what's wrong.

I'm gonna get this stinkin gauge to work if it kills me :wall:

Then I'll start working on the dumb crap like you know, brakes, tierods, engine :rotfl2:

[HOrnbrod]

Yeah, I started playing with this last night again. Changed out the sensor for another one fom Autozone to see if it would make any differnce at all. Nothing. Still reads high.

Don, do you have a whole other cluster with a cable driven speedo I can buy from you. I vaguely remember my temp gauge working correctly on the second cluster I had in there. It's oil gauge was shot but the temp worked right. I made the mistake of letting my two year old work on it with my drill :roll: .

After I change it out if I still get a whacked reading I'll start ripping the harness apart and figuring out what's wrong.

I'm gonna get this stinkin gauge to work if it kills me :wall:

Then I'll start working on the dumb crap like you know, brakes, tierods, engine :rotfl2:

 

I have clusters, but not complete w. gauges at the moment. But you could swap your existing gauges into an new cluster easily though (as you know well :D ). Shoot me a PM if you need one. Don

[chicofuentes0224]

PM sent homey :D

[Mountianrider]

Hey I know this is an old post but I have a Cherokee from Canada with the metric system installed. I'm begining to think these senders are designed for those vehicles. I had a Comanche which just about drove us nuts with this same issue.