Lightn95

Got 2 questions. I did the LT1 swap on the wire harness and it uses the stock temp sending unit on the front drivers side head. Where else can I tap into so I can use the temp guage in the car? It's a typical 1 wire hookup is all I need.

the other question is I had the ECU tuned by a local tunner, he turned on the 2 stock fan controls in the harness... forget exactly which pins they are, 33 and 42 I think. I wired up my fan using one of them. But my question is, how do they work? At what temp do they turn on the fan? I just wabt to make sure they truely are working before i cook the motor.

Thanks !

G Atsma

Rear passenger side head. The heads are identical.

Lightn95

I looked at that. That comes out? It doesn't look like it comes out and it looks like a solid round slug

G Atsma

It is a threaded hole just like the other head.

Michael Yount

iTrader: (1)

Keep in mind - the coolant will pick up a bit more heat as it moves from the rear of the head to the front. So the temp you see on the gauge from a sender in the rear of the head is likely to be a bit lower than the temp of the coolant leaving the block.

bobcratch

i'm using the passenger side head temp port for the gauge in my volvo swap. works fine. There are no numbers on the gauge, so i couldn't tell you how well the two correlate.

AwesomeAuto

LS heads are identical and interchangeable. There is no passenger side and driver's side. The plug in the passenger side head is identical to the port on the driver's side head for the coolant temp sensor.
That spot on the passenger side will typically read 20 or 30 degrees lower than the one on the front in the driver's side.
You can get an early 3-wire coolant temp sensor for an LS engine. Two wires go to the ECU like normal, the third wire was made to drive the coolant temp gauge directly. This will probably be the easiest and all around best option for you.

The ECU determines what temp the fans kick on. Your tuner can set them to whatever temperature you want. I often use one of them to run an electric water pump.

Michael Yount

iTrader: (1)

Depends significantly on engine loading. At idle and part throttle/light cruising, I only see a 10F delta through the whole engine -- 187F at the t'stat; 197F at the point where all coolant exits the engine.

Lightn95

Thanks everyone! I'll use the rear port on the pass side head. I'm not looking for exact degrees, I just need to make sure I'm not cooking the motor. The car is a cruiser/ warm weather driver.

ryeguy2006a

iTrader: (27)

Have you tried a code reader that can view live data? You can even buy a cheap OBD2 bluetooth reader and download the Torque app.