Stuck Thermostat?

[96GTS]

I was washing the Viper today, and let it run while I dried it to charge up the battery a little. I got in it when I was finished and noticed the needle on the water temperature was at 250. I had never seen it get over 190, even at a track event, so I was concerned. After thinking about it, I didn't remember the fan ever kicking on. Does it sound like the thermostat is stuck shut , or could it be an issue with the fan?

 

[dave6666]

Could be the sending unit too. Turn the AC on. Does the fan run?

 

[96GTS]

I ran the A/C for a few minutes and the fan never came on.

 

[dave6666]

Fuse or circuit breaker?

Check fan wiring connector at fan.

Does fan spin by hand? (Could be neighbors cat wedged...)

Do you have wiring diagrams?

 

[96GTS]

Fan spins freely and the fuses aren't blown. I'll have to check the connector tomorrow.

Thanks.

 

[WANTED]

Does the heater work ? Blowing out hot air.

 

[dave6666]

Also check your fan relay if '96s are so equipped. My '01 has one located in the power distribution center.

 

[96GTS]

The fan blows, but no hot air.

 

[dave6666]

We'll assume obvious stuff like there's coolant in the system? And you did twist the dash knob to hot?

Seems strange that there's no heat at the heater - aka no hot coolant circulating - but no fan either.

 

[96GTS]

It puked coolant for a little after I turned it off the first time, but I doubt it was more than a few pints. I had the knob set at cool to see if the fan came on with the A/C and then put it to warm to check the heat.

 

[dave6666]

Did you move the other knob to heat too? Just setting the temp knob to the red part won't give you heat unless the "heater" is on via the knob on the far right.

 

[Neil - UK]

The fan blows, but no hot air.

no hot air, and a quickly rising temp guage = water pump failure

just changed mine after it failed, the plastic impeller was loose and wouldnt spin on the shaft

dont drive your car until its sorted, to long at 250 and youll swapping the engine as well !

 

[dave6666]

no hot air, and a quickly rising temp guage = water pump failure

just changed mine after it failed, the plastic impeller was loose and wouldnt spin on the shaft

dont drive your car until its sorted, to long at 250 and youll swapping the engine as well !

Why doesn't the radiator fan come on then? Even with the AC on?

 

[WANTED]

no hot air, and a quickly rising temp guage = water pump failure

just changed mine after it failed, the plastic impeller was loose and wouldnt spin on the shaft

dont drive your car until its sorted, to long at 250 and youll swapping the engine as well !

I was thinking the same thing, Water pump.

 

[SNKVENOM]

Does the Guage rise slowly to 250 or does it peg to 250 when you start? If it pegs it is the sending unit mounted on the front of the motor. $ 50 dollar fix. Parts at Dodge.

 

[96GTS]

The gauge rises slowly.

 

[dave6666]

The gauge rises slowly.

What about checking the heater for heat. Did you switch the right knob to "heat" when you did that? As I mentioned above, just turning the center temp knob all the way right will do nothing unless the selector is set to heater.

And I don't mean to challenge you on that simple point, but based on the way you worded it above, it made it sound like you just twisted the center temp knob to hot while still on AC. That won't give you heat.

 

[96GTS]

When I moved the knob to defrost heat did come out.

 

[dave6666]

When I moved the knob to defrost heat did come out.

That suggests several things then.

-> You have coolant.

-> It is circulating. AKA water pump is functioning at least minimally.

Does the upper radiator hose get hot after the gauge reaches 220 or so? This would suggest the t-stat is open.

I'm still leaning toward the fan or some component of it. It's easy to get out. Put it on the bench and connect a battery to it. Or a battery charger. With the correct wiring diagram to assist. If I had a '96 manual I'd give you the pin outs on it.