temp sender unit

[BarryK]

I see that Corvette Clocks by Rodger is selling what he refers to as the "correct" temp gauge sending unit that is suppose to read accurately.
see here: http://corvetteclocks.com/page11.html
scroll to the bottom of the page to see the description.

anyone try one of these units yet and was it accurate? My replacement Wells TU-5 reads approx. 40* too high.

 

[ctjackster]

did you happen to see that recent post about a temp sending unit that you could adjust / calibrate by turning a screw? That got my attention.

As for the Wells TU5, seems to me you have to try a few and you might just get lucky. As ridiculous as that sounds, it is [for now] the only way to maybe get one that is close. Have no experience with the one you linked, am all ears though. For $20, it had better work.

 

[BarryK]

Jack

I haven't seen the adjustable sender unit and maybe it works but to me it sounds odd. What's the point of it? I would think that a sender unit should accurately reflect and send to the gauge what the actual coolant temp is and by using an adjustable one all you are doing is setting it to where you want the gauge to read, not what the actual temp really is?
Granted, I understand you would first shoot the housing with the IR temp gun to see what the actual temp of the coolant is than set the adjustable sender unit to that temp reading but still the idea just doesn't sit right with me for some reason.
I guess I just feel better with using a regular temp sender unit that is proper and accurate to begin with. $20 may be expensive for a sender unit but it won't break the bank if it works correctly.
Buying 3, 4, 5 or so Wells units until I MIGHT find one that works also seems foolish to me and for what that would cost i'd rather spend the $20 ONCE.

If nothing else I guess I can try a junkyard for an original out of any old '60's SB motor but I was trying to save the hassle of searching thru an old junkyard if I could find a new one that works accurately.

 

[ctjackster]

Jack

I haven't seen the adjustable sender unit and maybe it works but to me it sounds odd. What's the point of it? I would think that a sender unit should accurately reflect and send to the gauge what the actual coolant temp is and by using an adjustable one all you are doing is setting it to where you want the gauge to read, not what the actual temp really is?
Granted, I understand you would first shoot the housing with the IR temp gun to see what the actual temp of the coolant is than set the adjustable sender unit to that temp reading but still the idea just doesn't sit right with me for some reason.
I guess I just feel better with using a regular temp sender unit that is proper and accurate to begin with. $20 may be expensive for a sender unit but it won't break the bank if it works correctly.
Buying 3, 4, 5 or so Wells units until I MIGHT find one that works also seems foolish to me and for what that would cost i'd rather spend the $20 ONCE.

If nothing else I guess I can try a junkyard for an original out of any old '60's SB motor but I was trying to save the hassle of searching thru an old junkyard if I could find a new one that works accurately.

my thinking on that calibratable sending unit is this - since it has been shown that these things do not seem to be made with too much precision, it is a nice solution to be able to "dial in" the sending unit - one would need an IR gun, of course, but using one you could get that sucker perfect. The other solutions thus far, from the LL one with the resistor, to various others, have not worked consistently. I finally tried enough Wells TU5 units to stumble onto a perfect fit, but that's a crappy way to have to go about it.

 

[BarryK]

Jack
my thoughts on the adjustable one may be just a feeling and they are fine once they are dialed in - it just sits strange to me is all.
As for having to try multiple Wells units, you are right, that is a pretty crappy way of having to deal with the issue

 

[tigernut]

My new TU5 reads high as well.

It seems everyone's does.

So what we have here is either:

- a conspiracy in the temp sender world to sell more "products": radiators, coolant (something else must be bad), IR guns (temp sender manufacturers also manufacture IR guns), etc.

- evidence of actual global warming, reflected in higher temperature readings (accurate temp senders) on our cars combined with "defective" IR guns.



Doug

 

[BarryK]

that must be the answer Doug!

 

[cbernhardt]

Several years ago I took my multi meter down to the local Autozone and asked the counter guy to bring me all the Wells temp senders that he had in stock. They all checked within a few ohms of each other so I took one to put on my 62. The temp gauge was still off by about 20° so I added a variable resistor to "tune" it in at 180°. I check it every so often with an IR gun and it has worked well for about three years.
Charles

 

[BarryK]

Charles
that might be what i'll have to end up doing, but until I get to that point I still feel funny using the resistor method to get a proper reading. To me that is just fixing the symptom of the problem, not fixing the problem itself. perhaps my thinking on this is wrong, but I'd rather SOMEHOW find a temp sender unit that actually works correctly and accurately, even if i have to spend a day searching through a junk yard for an old original unit from a junker car.
anything else to me just feels like a "bubba" fix.
Please don't think i'm calling you a "bubba" because i'm not by ANY means, I've been on your website many times to look at the work you do and it's top-notch and I know many people have gone the same route on their own temp sender replacement units and it's worked, but it just doesn't feel like th best solution to me. there has to be a way to get a unit that actually works accurately.
I've had a number of people email me the tech aspects of the whole temp sender/gauge system, the temp/resistence chart on the original units, etc, and I'll go thru the entire system to check it and than find a proper temp sender unit that works. At this point it's become a challenge to make it work properly. and I try not to back down from challenges too much.
I have the whole winter to work on it along with my other winter projects so come Springtime maybe i'll have it licked.
............ and if i don't by than, THAN I'll break down and do the added resistor method.

BTW, I look forward to seeing more progress on your '59. Geez, with a big ole 572 motor in there that thing will be a monster!

 

[cbernhardt]

http://69.253.166.197/page1/page65/page65.htmlBarry:

I guess I chose the easy way out on the temp gauge problem. I'm not too sure that these old gauges were very accurate even when new. At least now I know it is correct at my "critical" (180) temperature.

I took a quick look at your web site and I know you have certainly put a lot of work into organizing all the pictures. The only odd thing I noticed was that your long menu items, like "Vette Tech Articles & Papers", or "Atlantic City car show 2005" tended to wrap around and overlapped with the next line in the menu. Might just be my browser though (Mozilla Firefox).

Charles

 

[BarryK]

Charles
Normally I like the easy way out also but resistors weren't needed origianlly I have a hard time putting them in now. also, from what i've read and learned so far, the original senders and gauges were not all that accurate originally and were really only more closely calibrated towards accuracies at the upper end of the scale (higher temps) where it was most critical. it seems that the tolerances started out somewhat sloppy at the lower ranges and tightened up more as the temp range increased so that it's more accurate reading something such as 220*, 230* or 240* rather than when it's reading lower temps like 160* or 180*.
From the tech articles i've read since the way the original system was designed, if I add a resistor to make it read 180* against my IR gun temp reading of 180* it would be fine for that temp and a small range of temps close to that, but at the same time it will probably throw off the entire resistence curve elsewhere, especially as it gets to higher temp readings where it's more citical to be accurate. Since the temp/resistence curve doesn't seem to be very linear, i'm not real sure and comfortable what adding a resistor will do to the readings lower or higher than where the resistor is to 'calibrate" it for a normal operating temperature.

I don't get the text wrapping on my browers and no one else mentioned it although it's possible i guess. This is my first website so i'm still learning. I greatly appreciate the feedback on it and I'll look into that issue to see if I can find out why it's doing that.

 

[cbernhardt]

Barry:
I tried your website on Internet Explorer, Netscape Navigator, and Mozilla Firefox. Only Explorer displayed the menu items correctly. One of those Microsoft "features" no doubt.
Charles

 

[BarryK]

Charles

I just checked it again here using Firefox, Explorer, Opera, and Safari (I use Macs), and not getting the text wrapping that you are experiencing.
i wonder if our default font sizes are different and therefore causing that to happen or if it's a difference in the way my Macs display the pages as opposed to the way Windows is displaying them.........
hmmmmmm, I'm going to have to look into this further.
thanks for checking again and letting me know.

 

[cbernhardt]

Barry:
You were correct about the text size being the culprit. I reduced the text size on my browser and that fixed the problem. Old eyes I guess.
Charles

 

[BarryK]

thanks for getting back to me regarding that Charles. I really didn't know how else I was going to fix the issue since the program i use to make the site is basically a "Website for Dummy's" type of program. It doesn't require knowing html or anything else but it has limitations because of that and changing the font size is not something I think I can do. at least not very easily.