temp gauge anomoly

[Not the Autorx Frank]

ok, so heres the deal. I have a temp gauge that reads consistently high. I have hooked up other gauges and used my infrared to confirm its 40f high across the board. I have got another duplicate of this same gauge. exact same readings. replaced sender. exact same readings. I was thinking of just adding a resistor in line w/ the sender to bring it in line so to speak. Or, should I buy a handful of senders and tinker??? any thoughts??????

the gauge is a teleflex....

thx

 

[brianl703]

Adding a resistor should work fine.

Might want to make it a variable resistor so you can adjust the reading to be correct.

 

[Not the Autorx Frank]

nice idea.

ok so where do i get a variable resister and is it just called a
"variable resistor"

thx!!!!!!!

 

[Eddie]

Try Radio Shack and ask for a minature potentiometer.

 

[Papa Bear]

I would just bend the needle on the gauge.
P.B.

 

[Papa Bear]

Mess with the electronics or mess with the mechanics. Pull the needle off and stick it back on in the right place then.

P.B. (jk)

 

[Tosh]

Or leave it alone and regard it as a differential (term?) gauge with 'normal' shifted upward. As long as it accurately shows 'hot' when it's hot.

 

[Papa Bear]

Frank: Would Teleflex recalibrate their gauge ?? Could they offer a little insight into your problem ?? Maybe the guy at the factory the day your gauge was made "stuck all the needles on wrong" and there is a TSB. Changing resistor values would "cover up" a fault. If indeed a resistor change is in order, perhaps Teleflex could tell you what value to use and which resistor to change.
If my car wasn't idling right, the LAST thing I would want to do is go in to the ECU (computer) and try to reprogram it to cover up the fact that I've got a fouled spark plug.
I am quite interested to find out what you discover with your gauge. I was an electronics tech for almost 30 yrs and saw a LOT of expensive repairs AFTER someone had tried to "tweak" something themselves. A $10 repair became a $100 repair in an instant.

Remember Frank, transistors run on SMOKE....once you let the smoke out, they don't work any more.

P.B.

 

[Not the Autorx Frank]

Bear,

Well they did send me a brand new gauge and sender but same results. I ran a make shift ground wire to the body of the sender to make sure it wasn't a grounding problem. No change. I went ahead and made up a 10ohm wirewound resistor in line and it got me 1/3 of the way to what it should read. Was reading 50f high and now only 35f ish hi. Do I need 30 ohms or 3 ohms. Not sure which direction the figures go. How does wattage play a role????
I'm going to dummy the gauge until Teleflex tech gets back to me.

Thanks Paps for your help!!!

Frank

 

[tom slick]

for a "variable resistor" you need what is called a potentiometer. I don't know what range you'll need though.

 

[Papa Bear]

How does wattage play a role????
Well, Frank, that's where Ohms Law comes into play.
Wattage is POWER and can be arrived at using:
E=IR I=E/R R=E/I
P=IE I=P/E E=P/I

E=Voltage can be either AC or DC
I=Current in Amps
R=Resistance in Ohms
P=Power in Watts

It gets a little complicated

I think the Teleflex tech is your answer, let us know what you find out.
I found a website with just about any formula you need at http://library.thinkquest.org/20991/gather/formula/index.html
P.B.

Actually you would probably need a rheostat, not a potentiometer. P.B.

 

[Not the Autorx Frank]

I love lamp.......

 

[Papa Bear]

We're going to get another dumping of snow tonight up here in Canada !!
Frank, you live in SoCal, it's obvious you really need some help there with your gauge. Mama Bear & I could come and stay at your place and get that gauge working like new !! We should have it up and running around the end of May

P.B & M.B. (waiting patiently for your call)

 

[Not the Autorx Frank]

quote:

---

Originally posted by Papa Bear:
I would just bend the needle on the gauge.
P.B.

---

forgive me but are you serious? LOL

 

[Not the Autorx Frank]

LOL Its gonna rain here tomorrow. But it will be gone by Tues. I'm gonna try a few diff resistors in the 35-50 ohm range. Most are near 10 watts. Of course I will press teleflex to figure it out. Wondering if I might need to isolate the ground on that gauge from the rest of the cluster...

happy shoveling !!!

 

[Papa Bear]

10 watts should be more than enough, probably 1/2 watt would be plenty. How many volts does it run on?? Remember I=E/R,so if it's a 9 volt battery into a direct short through 50 ohms, it's I=9/50 ie: I=.18amp Power=voltsXAmps, so the wattage you would want for your resistor is 9X.18=1.6watt.
That's not counting the resistance in series with your 50 ohm resistor.
If you're not sure though, it's never a bad idea to have your safety glasses and flame-proof jockey shorts on when you plug it in.

Good luck...P.B.

 

[Not the Autorx Frank]

ok just so everyone can rest easy now I'll tell you what teleflex said. I know you were all loosing sleep on this...

blah blah blah tons of variables blah blah blah go ahead and use a resistor 1 ohm per degree 2 watts.....

took 51k ohm 2 watt to get it in line. cost me 26.5 cents LOL

oh yeah and 3 bucks in gas

 

[Papa Bear]

Does that mean Mama Bear and I can't come and stay with you

P.B. & M.B. (We have our bags packed)

 

[Not the Autorx Frank]

LOL. stop in anytime!!!!!!!! I'll pour you a beer aye.