HELP

If the temp gauge goes up with rpm's and the battery light comes on, you probably have an electrical issue, since your alternator is charging more as the rpm goes up. i would seriously doubt your car stalling would cause engine overheating issues.
Does a mustang have a voltage limiter in the cluster or am I thinking of another brand? If it does maybe its your problem

boboli said:

If the temp gauge goes up with rpm's and the battery light comes on, you probably have an electrical issue, since your alternator is charging more as the rpm goes up. i would seriously doubt your car stalling would cause engine overheating issues.
Does a mustang have a voltage limiter in the cluster or am I thinking of another brand? If it does maybe its your problem

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The cluster uses a voltage regulator to limit the effect of electrical changes on gauge readings.

HISSIN50 said:

The cluster uses a voltage regulator to limit the affect of electrical changes on gauge readings.

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I thought I remembered that correctly.
So could this regulator be causing his gauge issues. Maybe it can't maintain the voltage especially with the increase in alternator output at higher rpms. Of course I don't know why this would set off the battery light but its just my hypothesis.

The IVR should not be the source of the issue. It uses a VREF that's less than half that of battery voltage.

A bad ground could be the issue (especially if the gauge reading changes if the headlights are turned on).

An secondary temperature reading (aftermarket gauge, etc) is also needed.

boboli said:

If the temp gauge goes up with rpm's and the battery light comes on, you probably have an electrical issue, since your alternator is charging more as the rpm goes up. i would seriously doubt your car stalling would cause engine overheating issues.
Does a mustang have a voltage limiter in the cluster or am I thinking of another brand? If it does maybe its your problem

Click to expand...

He already solved the battery light problem, his belt was slipping causing overheating and low voltage. he took the tstat out and fixed the belt, he still had the overheating problem so he put in a 160 degree thermostat and now has a different issue..
Why did you put the 160 degree tstat in? Whenever I have any issues with my vehicles I put stuff back as close to factory as possible. I'm not sure what your car is exactly but the factory one for me is a 195 iirc. Stupid little things like that are what always seem to screw me lol

Isn't the 160 stat too cold? Think about it... at 160, the stat opens... so it's probably always open once the engine heats up. If the coolant is always flowing it doesn't have a fair chance to cool off in the rad. Install a proper stat. Maybe the temp drops at higher rpms because the fan is pulling more air thru the rad?

check that the water pump spins freely. i.e. Take the belt off and turn the pump by hand.

Have you wiggle tested the wiring? The little stator wire is the first one to check. In addition to the regulator wiring, don't forget the battery cables and power distribution stud.

It could also be the internals of the alt flexing. You can't replicate that in a bench test very easily (I suppose you could hit the alt with a rubber mallet during the bench test).