4.0 sohc temp sending sensor

[xamdarb]

Hello all,
I recently bought a explorer and noticed it was leaking from the thermostat housing (nut was turning in housing and leaking fluid at ecu temp sensor).
I replaced the housing and also the ecu temp sender as the old one was cross threaded (the red one to the passenger side)

I reused the smaller white one on the drivers side, when I got the truck up to temp the temp gauge in the truck was not working. I would let it sit for a while and the gauge would go up slightly (with the key off) just below cold, when I turn the key to on the gauge would peg to as cold as possible.

This is weird as the sensor was working before I took it apart, the thermostat is working I have checked that.

I read a few places that you can ground the connector out to make the gauge read max. Hot do you do that on a two pin connector? Would I just take a safety pin and touch the two pins on the connectors together? My electrical knowledge is not great so I may need some help on this part.

Their s no way I put the connector on backwards is there? I think I will go buy a new sensor here tomorrow hopefully this fixes it.

Thanks,
Brad

 

[2000StreetRod]

testing sensor wiring

The temperature sensors are thermistors that decrease resistance as the temperature increases. Shorting the two wires together or shorting the RD/WH wire to ground would make the gauge indicate max temperature. The connector is keyed to prevent installing incorrectly or connecting to the wrong sensor. Since your gauge indicates cold there is probably just a poor connection to the sensor. An open connection would indicate minimum temperature on the gauge.

 

[xamdarb]

could you briefly explain how to go about grounding it to test the connector?

Thanks
Brad

 

[2000StreetRod]

grounding the connector

I don't know if you can access the sensor connector without removing the upper intake manifold. Anyway, one method is to disconnect the connector and push a bent wire end into the contact going to the Red/white stripe wire. Then push the other bent end of the wire into the contact going to the black wire. Then turn on the ignition and read the temperature. That checks the entire circuit except for the sensor. There may just be corrosion on the sensor contacts from the leaking coolant. Disconnecting/reconnecting the connector may clean the contacts enough to achieve good electrical connections.

 

[xamdarb]

Thank you for the help I will try that out soon.

No the intake manifold does not need to be removed but removing the throttle body makes life easier.