1998 Ranger Temp Gauge

[DavidG]

Hi everyone. I bought a 1998 Ranger 4.0 XLT 4wd 5sp about 2 weeks ago and have a question about the temperature gauge. The gauge works, but when cold, the needle sits about 3/16 of an inch below the lower line and, when warm, sits about 1/4" above the lower line.

I think the overall movement is probably correct and I think that if the needle started out at the lower line, that it would probably be halfway between upper and lower when the engine is warm.

Can someone please tell me where their needle sits when cold?

Also, does anyone know if there is a way to adjust the gauge so that the needle is in the correct position when cold? All may cluster lights are out and so will be removing the instrument cluster to replace - in case there is a way to change where the needle rests when cold.

Thanks for your help.

David

 

[Eddo Rogue]

My needle rises slowly as the truck warms up. There is no adjustment, which if there was, would probably be in the sending unit, because the gauge just says what the sending unit tells it to. I had to replace both the sensor and sender in my 4.0 to fix my gauge issues (it was all over the place). It may be possible your gauge is out of calibration, but I never heard of a gauge needing adjustment. I have heard of the gauge within instrument cluster itself going bad.

I am running a 195 degree thermostat and my needle sits at the C when cold. Rises slowly as it warms up, and settles in the middle at operating temp. It will move up and down slightly depending on driving conditions. I installed an aftermarket digital temp gauge as well, and it shows between 185 and 200 degrees operating temps (again depending on conditions). This is with my digital temp sensor pickup being plumbed into the heater hose up by the core.

 

[RonD]

Ranger's dash temp gauge has 205-210degF as center line
Engine coolant should run at 185-195degF, after warm up, so just below 1/2 on the gauge would be "normal"

Yes, temp needle can be below C at cold start

FIRST test if your thermostat is OK
Start cold engine, turn ON heater, and open the hood
Feel upper radiator hose at the radiator end, should, of course, be COLD
Feel either Heater hose, should be cold as well

Let engine idle 2 or 3 min, feel upper radiator hose again, should still be COLD
Feel heater hose, should be warming up

If upper rad hose is also warming up, like heater hose, then your thermostat is stuck OPEN, this will prevent the engine from full warm up and will cost you $$ in lower MPG
And its why temp gauge isn't going up to 1/2


If upper radiator hose is staying cold then thermostat is OK, could be the temp SENDER on the engine is failing
On lower intake manifold just above thermostat housing are TWO temp devices
1. ECT sensor, has 2 wires, uses 5volts, and is connected to the engine computer only

2. ECT sender, has 1 wire, uses 12volts, and is only connected to dash temp gauge

Look for the 1 wire sender, it has a red/white stripe wire, pull off the wire/connector
Use a jumper wire to GROUND that red/white wire
Turn on the key(engine OFF) and watch the temp gauge, it should go to HOT, all the way up
If it does then replace the sender, its not reading temp correctly

If gauge only goes up to say 3/4 then gauge is the issue, not sure if it can be fixed easily, never tried