B20 engine temperature sensors

Ian Fife · Jul 11th, 2014, 08:30

There are two sensors on the block of my B20 engined 440 (1994 model). One at the back of the block near the thermostat housing with a single wire, and one at the front of the block with a multiplug (2 wires I think). My temperature GAUGE has stopped working, but the engine still appears to run fine.
My question is - which sensor controls the gauge and does anyone have data which would allow me to check it? (eg resistance values etc.)

The Haynes Manual appears to give resistance data for the two wire sensor but not the single wire sensor (?)

thanks

Ian F.

doingitsideways · Jul 11th, 2014, 09:31

Hi.

The sensor with a single wire next to the stat is for the guage, the management sensor is the one with two wires facing forward.

There will be another sensor somewhere for the cooling fan, but I can't remember where that is at the moment.

Steve

glasgowjim · Jul 11th, 2014, 18:33

temp sensor for cooling fan is on the radiator.

Ian Fife · Jul 11th, 2014, 20:33

Thanks Steve and Jim, just bought myself a new multimeter and checked the resistance across the single wire (gauge) sender, seems to be working - resistance drops massively when engine moves from cold to hot.
Began to think about taking the dash apart to get at the gauge, but then connected up the sensor (after the test) and the gauge works again!!
Think I'll just leave it be, as the engine seems to work fine and it's never overheated, yet...............

Ian F.

doingitsideways · Jul 12th, 2014, 10:03

Good plan

Jul 11th, 2014, 08:30	#1
Ian Fife Senior Member Last Online: Today 08:57 Join Date: Jan 2006 Location: Inverkeithing	B20 engine temperature sensors There are two sensors on the block of my B20 engined 440 (1994 model). One at the back of the block near the thermostat housing with a single wire, and one at the front of the block with a multiplug (2 wires I think). My temperature GAUGE has stopped working, but the engine still appears to run fine. My question is - which sensor controls the gauge and does anyone have data which would allow me to check it? (eg resistance values etc.) The Haynes Manual appears to give resistance data for the two wire sensor but not the single wire sensor (?) thanks Ian F.

Jul 11th, 2014, 09:31	#2
doingitsideways The Daddy Last Online: Feb 29th, 2024 15:07 Join Date: May 2010 Location: Manchester	Hi. The sensor with a single wire next to the stat is for the guage, the management sensor is the one with two wires facing forward. There will be another sensor somewhere for the cooling fan, but I can't remember where that is at the moment. Steve __________________ XC90 V8 Exec, C70 2.4T Convertible, S70 T5 CD, 850 TDI, 2 x Escort vans and a 2.8i Capri. Clearout has begun, but must continue!

Jul 12th, 2014, 10:03	#5
doingitsideways The Daddy Last Online: Feb 29th, 2024 15:07 Join Date: May 2010 Location: Manchester	Good plan __________________ XC90 V8 Exec, C70 2.4T Convertible, S70 T5 CD, 850 TDI, 2 x Escort vans and a 2.8i Capri. Clearout has begun, but must continue!

Jul 11th, 2014, 18:33	#3
glasgowjim Senior Member Last Online: Apr 17th, 2018 15:45 Join Date: Aug 2008 Location: glasgow	temp sensor for cooling fan is on the radiator.

Jul 11th, 2014, 20:33	#4
Ian Fife Senior Member Last Online: Today 08:57 Join Date: Jan 2006 Location: Inverkeithing	Thanks Steve and Jim, just bought myself a new multimeter and checked the resistance across the single wire (gauge) sender, seems to be working - resistance drops massively when engine moves from cold to hot. Began to think about taking the dash apart to get at the gauge, but then connected up the sensor (after the test) and the gauge works again!! Think I'll just leave it be, as the engine seems to work fine and it's never overheated, yet............... Ian F.

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