Low coolant temp in Suburban

In a 95 suburban I recently bought the rear heat doesn't work. The front heat does work but not great.
I noticed that the temp gauge indicates only 140 degrees coolant temp which
seems low to me. Perhaps it is simply the gauge but perhaps this is all related.
What could cause this??
Uwe
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Make sure the thermostat isn't stuck open(make sure there even is one). Is the coolant low? Are the heater cores plugged? Is the fan clutch locked up?

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"Jaggy Taggy" wrote:

Check for bad thermostat (or if one is even present) for starters.
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