91 S10 coolant temp gauge (Page 1/1) reh OCT 01, 03:29 PM 91 S10 Temp gauge pegs 260 with ignition om regardless if sender is connected or not. 2.5 engine, 5 speed. vin E. suggestions appreciated. thanks. installed good sending unit with same results. carnut122 OCT 03, 05:42 AM Since it's pegged whether it's connected or not, I'd assume it's getting no signal from the sender. Since you put in a new sender, I'd check to see if the sender is getting a differentiated signal (cold vs warm). I assume this would be measured in voltage, but it might be measured in resistance instead. If it's not receiving a "signal, then you need to work back to its source. You'll need a multi-meter (Harbor Freight gives them away but you need the coupon and need to make a purchase).