95 Ranger 4x4 auto 4.0L coolant guage

[Mwlock]

Hi. My guage was not working properly. Barely moved at all. I replaced the temp sending unit and now it lifts from below the bar to just over it no matter how long it runs. I get great heat. What else do I need to consider to fix this guage?

 

[fastpakr]

Do you have an OBD2 scanner that can give you live data? First order of business in my mind is confirming that it's coming up to the correct temperature so you know for sure if the issue is the gauge vs coolant temp.

 

[Mwlock]

Do you have an OBD2 scanner that can give you live data? First order of business in my mind is confirming that it's coming up to the correct temperature so you know for sure if the issue is the gauge vs coolant temp.

I have access to a reader. I will see if a code comes up after my O2 sensor is replaced and I get that code cleared

 

[fastpakr]

If your reader supports it, look at the coolant temperature as the vehicle warms up. It should steadily rise to whatever the thermostat's temperature as (probably 192?) and then fluctuate around that temperature steadily.

 

[Mwlock]

If your reader supports it, look at the coolant temperature as the vehicle warms up. It should steadily rise to whatever the thermostat's temperature as (probably 192?) and then fluctuate around that temperature steadily.

Thank you

 

[RonD]

The coolant temp sender connector should have a red/white wire, that wire runs to the cluster and temp gauge
Disconnect connector and use a jumper wire to GROUND that red/white wire to battery Negative
Turn on the key
temp gauge should go up to full HOT
This means that red/white wire and the gauge are OK

If the connector has a 2nd wire, black/white, thats the ground for the sender, put jumper wire between red/white and black/white wires
Turn on the key
Should see the same Full HOT on gauge, if not loose or bad ground wire

If there is only the red/white wire on the sender then the THREADS of the sender are the GROUND, so do not use tape on the lower part of the threads, the sender needs a good metal to metal ground to the engine

If wires and gauge test as OK, then new sender is bad, period


Thermostat can also be stuck open causing lower operating temp
Heater can still be warm but not HOT
Start cold engine and open the hood
Feel upper rad hose and heater hose
Both will be cold
Let engine idle for 2 or 3 minutes

Feel both hoses again
Heater hose should be getting warm, upper rad hose should still be COLD, if so thermostat is OK, if upper rad hose is also warming up like heater hose then thermostat is open and shouldn't be