hello my caprice 94 v8 4.3 engine gauge tempreture all time cold i test gauge by grounding its ok i test gauge by ovm and variable resitence and it is ok
i remove sensor and test it it is not faulty
shoud i replace a new one
the sensor i removed its a ac deloc 213-77 it does not work
thanks for help

I am confused, you say you tested the sensor, and it is not faulty, then you state you removed it.
Why would you need to replace it if it is not faulty?

Have you tested to be sure the dash gauge is working correctly?
If not get yourself a multi pack of resistors from somewhere like radio shack, and disconnect the Engine Coolant Temp sensors plug, and between pins A & B, which is the two end pins, put a resistor in there bridging A to B.
The following info was taken from a guy named Enslow'* post in my thread on 3800pro.
""Find yourself a 50 ohm, 180 ohm, and a 1450 ohm resistor. Connect these resistors one at a time between terminals A and B and look at the dash guage. The 50 ohm should give you the max, 180 ohm should give you 100°C, and 1450 ohms should give you 40°C.""
There is a little bit of helpful info in the thread I mentioned, so I'll give you a link to it.
Temp Gauge on Dash - 3800Pro.com Forum

Here is a link for Temp vs Ohms
http://redshift.homestead.com/Schema...mp_vs_Ohms.jpg



Have you turned your cars heat on to see if it has heat after the engine has ran for a few minutes?
If it doesn't then your thermostat could be stuck open.

i believe the v8s have two temp sensors, one on the driver side head for the inside gauge and one by the rad hose housing for the computer.

You are probably right, if so there would only be an A & B on each sensor, so they'd need to find out which one sends into to the dash.
Of course this would just verify that the dash gauge is functioning properly, if it is then with the sensor installed, I'd back-probe it and see what ohms it shows when the engine is cold, then let it warm up a bit and see if the ohms changes, if it doesn't then the sensor will need to be replaced.
It sounds like they already verified the sensor was functioning though, which is why I suggested verifying the dash gauge is functioning correctly.


Their post is a bit confusing, if the original sensor was replaced, it is possible they got one that does not have the same resistance values, I found out when I replaced mine that not all listed replacements were the same, of course it still functioned, just the dash gauge was a few degrees off from what it was during normal operating temps with the original sensor.

kinda sounded to me like the sensor he tested was fine, which is why i posted there are two and maybe he tested the pcm one and not the gauge one

thank you for reply i try to rewrite my post again clear as i can
i removed the sending unit sensor from the engine
1- i test when its cold using ovm i got zero reading
2- i heated the bottom of the sensor i measure now got reading of 1400
this tells that the sensor is responding to heat change

but this only works with ovm when put the sensor back in the engine and
let warm up the gauge does not move only stay on cold
i tested the gauge by grounding the wire while sensor disconned it works
ok indicater move to hot
i tried other way to test the the gauge connect variable resistor between groung and
the gauge i works and the gauge move to the hot side according to resistor
value i choose
now i am thinking of what you said may be the sensor not for this car even if i has same number and brand
thanks for your help
can intall other brand

if the gauge moves with the resistor it should with the sender. unless the plug or wires is messed up

THANKS
the wire i tested its ok and the plug

Ok, so it sounds like the sender is responding to change.
But, unless they reversed the way the senders work vs ohms then I am a little confused, you should have seen more ohms of resistance when the sender tip was hot, opposed to more when it was cold, if you look at that chart, as you notice the ohms go up as the temperature goes down.

What was the resistors resistance value that you used to get the dash gauge to show hot?
Around a 50 ohm resistor should have it pegged almost all the way hot, and a 1450 ohm resistor should have the dash gauge most of the way to cold.

The fact that the wiring connector you added the resistor to made the gauge moves tells me that if you do have 2 senders, we at least have the right sender that works for the dash gauge.
Which means it has to be either the sender is the wrong one, or as JW said, you may have a short in the wiring harness plug for it.

I am trying to look over some diagrams of your motor, and it does look like you have 2 coolant temp senders as JW mentioned, one for the dash gauge, and one for the computer.
Where is this sender in question located on your motor, I am seeing 2 senders listed for one near the waterpump, ACDELCO Part # 2134396, and another ACDELCO Part # 213928

There is also a third sender part number listed, but this one appears to be located near the right side of the exhaust manifold, its part number is the one you mentioned ACDELCO Part # 21377
I'll attach a pic of the location of the one in question, and another pic of the one I am seeing that has 2 part numbers listed, I'll list part numbers in the pics to better help you.

Don't look right. That is a tpi engine. I think his is a tbi. only the highest trim 5.7s and 9c1 caprices would look like that.