So I got the truck running just fine. I'm trying to figure out why i'm not getting a temp read back from the engine.

I've tied the stock 3.0 dash harness
C2 14. yellow / green = Water Temp Sensor

to

3.4's
II3 21. yellow / red = Water Temp Sensor/Sender

are the units different? and do i need to use the 3.0 sensor? what gives anyone had this issue?

thanks.

 

mine is just fine. To make sure you've got the right wire, do this. With the key on, touch the wire that you think goes to the dash to a ground. If the guage jumps to hot you know the guage is good, assuming the temp guage worked before.

 

yes it did... also the top radiator hose is hot, and the bottom is pretty cold. is this normal.

i will try this tomorrow, i just left the shop =(

 

grounded the yellow/green wire from dash harness and the gauge spiked up to hot. so the gauge works. whats the method of testing the sensor, and isn't the sensor located under the damn intake manifold? because if it is.... crap.

 

sensor is at the very back of the intake manifold. Its a single wire. So we know now that the gauge works. When the truck is fully warmed up and the thermostat is open, the two hoses will both be hot. When its cold the lower hose will be cold. Hook up a scanner to the obd2 port and when you think its Hot, check the coolant temp reading in the live data.

 

I wish I was so lucky to have a nice reader like that. Mine just checks codes. I'm thinking of ordering the ELM5 OBD-II scanner, and SCANXL PRO. So the water temp sensor is a one wire hookup, hrm.... I guess the only way to gain access to the sensor is pulling the damn intake off, because it's so close to the wire wall. I guess testing the sensor to see if it's reading, I could boil some water and dip the sensor in it and see if the gauge moves. Kind of ghetto, but should work in theory.

 

Will be keeping an eye on this thread. I am fighting the same battle. Tried the 3.4 and then the 3.0 sensor. Then I tried an alternate guage (even though I know the one from the original 3.0 cluster worked fine), no luck. I am now keeping track of my temp with a Scanguage II OBD II scanner which reads from the front temp sensor. Good luck.

 

maybe you've got the wrong wire from the 3.4 harness? I have no issues bro. And you don't need to pull the upper intake off bro.. just gotta move the wire harness a little bit.

 

this is possibly but i checked the wiring diagram at least 10 times. I'm going to have to trace wires for breaks and what not.

Well I'm up and running so that's a start. Only throwing two codes, which are the front and rear o2's. So i'm pretty confident I got the wiring right... =0

I'll give more details tomorrow, on what happens.

 

hows the oil pressure reading?

 

oil pressure is reading perfect. gauge's working like a champ. I swapped in the sr5 cluster and picked up a 88 oil pressure sending unit at autozone. Couldn't be happier with that. I think that was the only thing in their system that could come up... But no longer the less it works.

 

The ewd was wrong on the water temp when I did my swap. The color is right just the location is wrong. Look where your harness meet.

 

If the color is right, then it should work. Because what I did was cut off the 3.4 dash connectors and soldered on the 3.0's dash connectors. So the pin out shouldn't be wrong then. As basically the 3.0 dash harness gets soldered into the yellow / red. As pin location cannot be incorrect. I'm going to do it the old fashion way. I'll put the multi meter probe on the sensor's wiring, and then probe the connections under the dash. Which ever one shows being closed circuit is the one i will use....

but i'll still double check with this location bit, which i don't think it effects me.

 

Going to throw a curve ball at you, but...

Did you burp your cooling system since you've done the swap? Hot upper, cold lower indicates to me that you've got an air pocket and your coolant sensor might not be reading anything but air.

To burp these things, you have to get your rad cap so that it's the absolute highest point in the system. For me, that meant getting the front up on ramps on my sloped driveway, turning the engine on and letting it get hot enough to open the thermostat, turning the heat all the way up inside, and adding coolant as the level dropped.

My 2 cents.

 

well that's worth a shot i will test it tomorrow. but then again how do i know it's officially hot.... maybe i should wait for my obd2 scanxl tool for my laptop so at least i can get a solid reading from the coolant sensor for the ecu... but i'll keep this in mind.

 

heading to the shop i'm going to try the radiator burping trick. I'll just get the truck on jack stands.... as high as possible.

most likely i will post results in the morning.

 

Just make sure the cap is the highest point.

 

Found the issue. Epic Retard. Some how the wire going to the sensor got unplugged. Works like a champ. Drove the truck to my house which is about 20 miles away from the shop. Throwing codes for the o2's and the VSS. So far so good! Thanks guys..

 

At least it was something simple.

What do you think of the newfound power?

 

I wish I had a 6th gear on the freeway now. Hell I thought I was in 4th the whole time. =) Plenty of power, and it would pull nicely in 5th.. Crazy!