As soon as the Key is on, the units go to the hot position. the in dash is original, the aftermarket is new, the Heat sending unit is new, new radiator, new thermostat, new everything. what did I miss, its all grounded. all the other gauges work. these two just pegged at extreme hot.

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Yeah, I think the wire to the sending unit is shorted to ground.

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Joshua

will check this. thanxs

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Your not trying to use the same sending unit for the stock and aftermarket gauge are you?

ah, yes.

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That won't fly. Each sending unit can only drive one gauge. You may be able to add circuitry to make it work.

Disconnect the sensor from the aftermarket gauge and make sure the stock setup works.

The aftermarket gauges I've seen aren't compatible with the stock sensor. Even if yours is you would need a second one. Once you have the right sender for your aftermarket gauge drill and tap a hole in the thermostat housing for it. Or check for any unused bungs in the top radiator tank. This will only give accurate readings after the thermostat opens.

If you want to monitor the warmup itself... I know some heads have two threaded ports for stock setups that used multiple sensors. See if your head has enough meat in that area for a second hole. Or move the stock sender to the housing and put your aftermarket one in the head.

thank you for that, couldn't figure it out for nothing, will change it Tuesday morning

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there is a plug in the back right of block, can I put a temp unit in there?

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Generally you want to monitor the water outlet temperature. At the block drain the coolant has not yet circulated through the head so it will read lower than at the water outlet.

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Joshua

ok, I have an extra thermostat housing and will tap that. I really cant extend too far into the housing since it will get in the way of the thermostat right?

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You should be good to go on placing thermostat sending unit in thermostat housing as thermostat sits flush with face of head with its valve inside of head. Just double check the length of the sending unit with the depth of housing before drilling.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Offset the hole from the center of the thermostat a little to get you slightly more clearance. Sensors are usually NPT thread so make sure you have the right tap.

I've seen adapters that fit inline with the upper hose and have a threaded fitting for the sensor in the middle. Pretty sure it was at summit or jegs but don't quote me on that.