How to Install an Oil Temperature Gauge

  • 2-3 hours
  • Intermediate
  • 25-60
What You'll Need
Temperature gauge
Mounting screws, mounting panel
Three eyelet terminals, spade terminal
Hookup wire
3 lock washers, and 2 brass washers

The oil temperature gauge monitors transmission oil temperatures and warns you before the oil get too hot. If the oil temperature gets too hot it can mess up your transmission fluid or possibly cause transmission damage. The normal temperature should be between 150 degrees F and 250 degrees F. The oil temperature gauge works with all 12 volt negative ground systems. To install a new oil temperature gauge, you will need the tools and step-by-step guide below.

Step 1 – Battery Disconnect

Disconnect the negative battery cable.

Step 2 – Mounting the Temperature Gauge

You can mount the temperature gauge in a few different ways. You can use a mounting panel by installing the panel in position and using 2 sheet metal screws. If you are installing it on the dashboard, you can drill a 2-1/16” hole into the spot on the dashboard you would like to mount it. Use a gauge pod which will allow the gauge to press into a 2-1/16” gauge pod. You will not need the mounting bracket if you use the gauge pod.

Step 3 – Running the Wire

Connect a wire to the gauge stud to the sender unit. Secure the end of the wire with a nut and a lock washer or an eyelet terminal. Install the terminal on the sender unit stud. Tape the wire in position so it will not touch any hot engine parts. Run wire from the temperature gauge to the ignition switch. Install an eyelet terminal on the end of the wire and press it with the pliers tightly. Install terminal on the stud and place lock washer and nut. Tighten the nut securely. Do not over-tighten. Tighten the lock washer and the nut that is on center terminal. Lastly, run wire from the temperature gauge to the terminal board. Leave open 1/4” of the end of the wire at the temperature gauge. You can install the female spade connector and tighten it with a pair of pliers.

Step 4 – Reconnecting Battery

Next, it is time to reconnect the battery cable. Turn on the ignition. The gauge should read the oil temperature. Turn engine on and check for any leaks. The oil temperature gauge should adjust as the temperatures warm up.


If the gauge shows no reading at all after the installation, it can be that it is not hooked up to any power or it is not grounded properly. If the gauge shows a false reading, the sending unit may not be properly grounded. If your gauge reading is too high, the power and ground wire may need to be reversed. If the needle goes all the way to the right, the lead to sender assembly is accidentally grounded. These are a few things to check for after installation.