The Stovebolt Site Forums The Shop Area Engine Shop Engine Temp. Gauge 57 Chevy P/U

Hello all,
I have a straight 6 stock engine. The 57 P/U was bought new by my father. I am trying to figure out the oil temp. gauge. The original pink and green wires are still there but are not working. There is a tube that runs from the sensor on the block through the firewall and screws into the back of a gauge mounted under the dash. I do not know how to put a photo on my posting here but I posted the photo of what I am talking about on my profile page. If you look at the photos you will see a green wire on the firewall. Could this be the same green wire coming from the dash? I want to put it all back to the orginal way. How do I do it??
I think the sending unit I need is on the American Classic Truck web site. Part number "SP8151-Temperature gauge sending unit, reproduction, for electric gauges, with pin grip terminal connection." But I just want to be sure. Thanks again! Jon

You mean this one? http://good-times.webshots.com/photo/2179403520103635702cJQVek
It sure looks to be the right one to me.

the temp gauge will have one wire to the engine sensor [dark green], and one to the ignition sw [pink] - the hard tube is to the oil pressure gauge from an oil passage fitting ... and yes, that's the correct sender, and you have the correct type of terminal end on the wire

Bill [the other one ]

[same exact time stamp too!] weren't me, the puter gremlin musta dunit

Uh oh! double post! The hard line mentioned is going to an aftermarket gauge under the dash.

Hey guys!
Thank you! I had to sit there for awhile and get the slow wheels turning to see that dark green wire sitting there on the firewall yelling at me! Can you tell me how you post a photo from my web shot to the posts so people can just click on the photo link?

Mucho thanks!

When you have the image you want, Highlight the address bar, right click, and select "copy". Then, at the point in your post you want to show the link, right click and select "paste". This is the simple way. To create a "hyperlink" you will press the little globe with a chain.(the first button on the reply screen) Right click again, paste your link into the first window that pops up(select OK), and your title into into the next window(select OK again). The "hyperlink" turns this:

http://good-times.webshots.com/photo/2319266270103635702iRTbcn

into this:

Picture of "Uncle Rod" at the ranch

Hello all,
Can someone tell me how the green wire attaches to the temp sensor? Does the green wire just plug onto the sensor? Was not sure if there was a male/female connection... Thank you! Jon

I am pretty sure the end of the sensor has a brass "nail head", and the clip slides onto it.(at a right angle to the sensor)

54TOW,
Yes I was looking at that. I was hoping it would be like the gauges on the back of the speedometer...but the original green wire looks like a male connection. There must be a wire that clips on the sensor and then plugs into the green wire...not sure...

Rod - the wire end in your pic above looks like the original female end that clips onto the sender stud, it's a split brass plate inside the plastic .... you maybe have a different sender? it should be as David sez, a brass nail-like stud sticks out of the sender, the terminal slips onto it - not quite like on the gauges, but similar

Bill

Temp Switch
Bill,
This is what I thought I needed. I tried to push the green wire up a bit but it would not budge. I hope I have the right parts! Temp Switch 2

right wire end, wrong style sender ... should look like this

Bill

Bill,
Got new temp sensor with "nail head." Installed it and pluged green wire on. But now the gauge in the speedo is not working. Checked wire diagram and pink goes to ignition wire and green goes to the sensor. If you were to turn and look at the back of the speedo, of the two connections on the temp gauge the green goes to the right and the pink to the left. All hardware is new..Any ideas would be great! Thanks! Jon

Maybe a loose plug at the sensor? Is the green wire a new wire, or the old one?

yes, do a continuity check on the wire, and you can check the gauge by grounding the sender wire - open/grounded should read C and H

Bill

Ok,
I have power in the pink wire from the ign sw up to the gauge. I am guessing the green (old) wire from the gauge to the sensor is a straight shot? The green wire would be the ground? I put a test light to the green and nothing. Could it be possible that I crossed the green/pink wires at the gauge? I plugged the wires on according to the wire diagram. The reason why I question this is, because on the gas gauge I had to swap the wires because it would not work as the wire diagram showed...This is my last electrical problem! Then everything works again! Thank you for your help! Jon

yes the green wire is ground, sometimes - the sender is a "variable resistor" to ground, less resistance as engine heats up - if you short that green wire to ground you should see the gauge move ... could be the gauge is bad

Bill

Bill,
Sorry to ask this crazy question...
How long does it take (on average) for the engine to be running for the needle to start moving toward hot? thank you.

what's average? should show some action after say 3-5 min at idle, but the 235 is a cold blooded beast in my experience -it'll depend on the thermostat too, 160, 180, etc, and with no thermostat they never warm up ... my 57 235 would stay less than 1/4 of the way up when at operating temp [180 stat], and the only time I ever saw it move above center was once a hose sprang a leak and it lost nearly all the water

another thing to notice is if there's just a flicker of movement when you turn the key on, the needle usually goes "below the peg" when shut off, and will jump to 0 when you turn the key on cold

Bill

Yes I thought so! The after market guage dad put on would run at 180. Seemed to take awhile to get up to that. Thank you

Bill,
Checked everything. Still the needle does not move. What would happen if I swap the pink and green wires at the gauge inside the speedo? That is the only thing I can think of...

Hello Bill,
The gauge is working. The pink and green wires were crossed. The color wire diagram I have was wrong. Thank you for the help.

Bringing this back from the dead since I'm having the same problem. If the gauge doesn't move when I ground out the green wire and I've tried two different gauges what should be my next test?

Thanks!
Alden

if the gauges are used originals, you might try a 3rd
if you know a gauge is good, then you should make sure you actually have power to it - the sender is a thermistor, heat causes variation in the resistance to ground, controlling the current flow thru the gauge .... so, a good gauge with power should jump when you ground out the wire to the sender - if it does, but doesn't work hooked up, it's a bad sender [don't use teflon tape installing a sender], if it doesn't move it has to be a bad gauge or no power [bad wiring some where, check continuity from gauge to sender, and voltage at gauge to ground]

Bill

Can I pull the cluster out and check the voltage with the gauge cluster out? I was under the impression the cluster needed to be in to be properly grounded.

could be done, but would have to be real careful with the wiring powered and the cluster loose .... and yes, need to put a temporary ground from the cluster to the dash ... could maybe check using the ign sw easier, the pink wire Jon mentions should go from the ign sw to the power terminal on the gauge - with the key on you should read a voltage from that pink wire to ground, or [with the key off] there should be continuity [ohms] from there to the green wire at the engine [using any piece of wire to reach]

Bill

ok that makes sense, I'll give it a shot (btw to answer an older question one gauge was old, the other is brand new), thanks for the help!

don't discount the new gauge being defective, give it the continuity check

Bill

can I do a continuity check on the gauge with my multimeter by just touching the two connections on it with everything off? I'm completely ignorant on electrical so feel free to really dumb it down

should work, as long as it's not reading a short someplace else with the wires still connected, be as well to go from the ignition sw terminal [pink wire] to the under hood wire to check the complete circuit .... think of wiring like water hose, with the water being the electricity, need to prove a flow all the way from the "tap" to the "sprinkler"

Bill