Engine Temp. gauge

[hondarider188]

Ok sorry about the confusion and yes all i did was plug in the wire to the sender. The gauge didnt work at all when i got the truck and when i hooked it up it maxed out past hot. Yet when i unplug it nothing happens, so im not really sure but ill try the test again to make sure. Another strange thing did happen with it today, so when i started the truck the gauge was still maxed out past hot then a minute later it dropped down to cold, then a while later on the road went up over hot and after that dropped down just barely below the half way point which was pretty corresponding to my aftermarket i hooked up as a temporary. moments later back down to cold and hasn't moved since. so im not really sure whats going on.

[bd]

Let's try a different approach...

Go to Radio Shack and purchase a 100-ohm, 1/2-watt resistor (they cost about $1.50 for 5).  Unplug the wire from the sender and insert the resistor between the wire and a good ground.  Switch the ignition ON and the gauge should register exactly half-way between cold and hot.  Drive it around with the resistor installed and the gauge should remain stable at mid-scale.  If it does, replace the sender.  If it doesn't, you either have intermittent connections or a bad gauge.

[hondarider188]

sorry i havnt been able to do the test that you mentioned. But i think that i either have a bad sending unit or a bad connection. When i hook up a jumper wire sometimes it does react to it and other times it doesnt so its just kind of a chance that it will work. and the same thing happens when the gauge is hooke up to the sending unit, so what i mean by that is nearly all the time the gauge is maxed out when im running, but sometimes when i am going down the road all of a sudden it will pop up to a little ways above cold yet im running at full temperature. One more thing i should mention that i dont think i did before was that when i turn the key on it goes way beyond the max to the full extent and then when the key is turned off i can watch it go back up to say a neutral position which is about 1/4" past the Hot mark. Sorry for all of the information at once but i want to make sure you guys realize  everything that is going on with it at the moment.

[hondarider188]

ok my next question is where do i get the same engine temp. gauge at i have looked at   and classic parts but i dont see the same sending unit with the same type of connection. I do think that im going to start with the sending unit since its the cheapest. like i said in my last post i believe that the connector for the wire to the unit is bad, because it  looks like it has been melted like it fell down onto the headers at one point. is the sending unit a water temp. unit or does the get the temp. off of engine oil.http://www.classicparts.com/Switches/products/369/8/0  or is it one of those sending units?  thanks

[roger97338]

Let's try a different approach...

Go to Radio Shack and purchase a 100-ohm, 1/2-watt resistor (they cost about $1.50 for 5).  Unplug the wire from the sender and insert the resistor between the wire and a good ground.  Switch the ignition ON and the gauge should register exactly half-way between cold and hot.  Drive it around with the resistor installed and the gauge should remain stable at mid-scale.  If it does, replace the sender.  If it doesn't, you either have intermittent connections or a bad gauge.

Apologies for not contributing to the thread, but I'd like to ask how you know to do something like this. It's absolutely brilliant!

[hondarider188]

does anyone know where i can get the correct sending unit and the connector.

[bd]

83 K10 5.7L w/gauges: 

This temp sender and either one of the "PT261"  or  "PT1043"  AC-Delco Connectors pictured in this list (or similar connector) should work for you.

Replacement temperature senders have changed appearance since they were originally installed in our trucks.  The difference in appearance is not important.  You just need to make sure the sender is made for a gauge and not a warning light.

[hondarider188]

thanks bd but if your right about it being the same sending unit, but a different apperance then getting the original connector wont matter. but thanks for the link anyway the PT1043 is the exact one i would need.http://www.classicparts.com/Switches/products/369/8/0 so product number 53-819 on the second to last row. would be the correc sending unit?

[bd]

...so product number 53-819 on the second to last row. would be the correct sending unit?

Part number 53-819 is the wrong sending unit...
      P/N 53-819 (1/2" - 14 pipe thread) is for big block applications!

You need P/N 53-821 on Classic Parts' website.  The Chevy/GMC small block 350 uses a 3/8" - 18 pipe thread sending unit.

Be prepared to lose a little coolant.  Install the sending unit with 2 wraps of Teflon tape and a smear of Teflon paste on the threads.  Be careful not to over-tighten the sender with excessive torque, or you could damage it internally.  Just get it good and snug with a ratchet & socket or box wrench.  Be sure to refill the cooling system and check for leaks when you're done.

[bd]

Let's try a different approach...

Go to Radio Shack and purchase a 100-ohm, 1/2-watt resistor (they cost about $1.50 for 5).  Unplug the wire from the sender and insert the resistor between the wire and a good ground.  Switch the ignition ON and the gauge should register exactly half-way between cold and hot.  Drive it around with the resistor installed and the gauge should remain stable at mid-scale.  If it does, replace the sender.  If it doesn't, you either have intermittent connections or a bad gauge.

Apologies for not contributing to the thread, but I'd like to ask how you know to do something like this. It's absolutely brilliant!

Roger, sorry for the delay.  All the information is available in our Technical Pages.

[hondarider188]

ok thanks bd i was just getting ready to order me the 1/2" unit. but i think i am going to order it through classic industries instead just because they have a few other things i need that classic parts doesnt, so this way i dont pay shipping twice. and ill post a link to just to douple check it the right one(3/8").

[hondarider188]

never mind about that last post i finally did find the other part i needed at classic parts. so thanks for the help i will let  you know when i get it ordered, put in and the results.