stock thermo switch ground question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

jafero · 02-25-2007, 08:36 PM

I'm making a new air condenser fan circuit with relay kit I bought from ebay.
I would like to use stock thermo switch (that is attached into lower coolant hose) with this relay kit. However this kit has one wire for the stock thermo switch while stock thermo switch has two wires. If I ground this stock thermo switch and hook it upto the relay, will it still work for the air condenser fan?

g6civcx · 02-26-2007, 03:52 AM

Oh boy. You need a fan controller.

The thermo switch has 2 wires because it measures resistance as a function of temperature change. The fan has 1 wire because it needs to see 12V (+) to draw power. A relay triggers a large current when it sees a small current.

How can the thermo switch possibly trigger a relay when the thermo switch doesn't have current flowing through out?

http://www.frsport.com/DIF_Dual_Fan_...40SX_t_22.html

jafero · 02-26-2007, 07:58 AM

Thanks for the advice. One more question.
I have seen this relay kit on a friend's car.

When you see this close, you will notice that the thermo switch has single wire and is grounded by the fitting. My ebay kit is same set up as this. I wanted a set up like this using the stock thermo switch.
Is the Nissan thermostat with two wires totally different kind from the thermo switch in that picture so that grounding it to engine or chassis is totally impossible?

If so, where can I get a thermo switch or sending unit that has same thread size as stock thermo switch?

g6civcx · 02-26-2007, 08:03 AM

Quote:

Originally Posted by jafero

I wanted a set up like this using the stock thermostat but I guess not. Where can I get a thermoswitch or sending unit that has same thread size as stock thermo switch?

I don't understand your question. The thermostat is a mechanical unit housed in the water inlet and used to regulate coolant flow. The thermoswitch is a little screw-type sensor that measures coolant temperature for the ECU.

You cannot remove the stock thermoswitch because the ECU needs to monitor coolant temperature.

I have no idea what you want to do. The only options you have is either follow the link I posted above, or insert another thermoswitch for the fan controller somewhere else, preferably the upper radiator hose.

Don't mess with your stock thermoswitch.

jafero · 02-26-2007, 08:41 AM

Sorry to confuse you.
I meant the thermo switch, not the thermostat.

There are two thermoswitches in the car and the one located by the coolant bleeder hole monitors the water temp for the ecu, as far as I know.

projectRDM · 02-26-2007, 09:03 AM

The 2pin sender is for the ECU, the single pin is for the OE gauge. You can replace it with an aftermarket sender since the OE guage is crap.

jafero · 02-26-2007, 09:32 AM

Thanks! You know any aftermarket sender that have same thread size with the stock thermoswitch?

02-25-2007, 08:36 PM	#1
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	stock thermo switch ground question I'm making a new air condenser fan circuit with relay kit I bought from ebay. I would like to use stock thermo switch (that is attached into lower coolant hose) with this relay kit. However this kit has one wire for the stock thermo switch while stock thermo switch has two wires. If I ground this stock thermo switch and hook it upto the relay, will it still work for the air condenser fan?

02-26-2007, 07:58 AM	#3
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the advice. One more question. I have seen this relay kit on a friend's car. When you see this close, you will notice that the thermo switch has single wire and is grounded by the fitting. My ebay kit is same set up as this. I wanted a set up like this using the stock thermo switch. Is the Nissan thermostat with two wires totally different kind from the thermo switch in that picture so that grounding it to engine or chassis is totally impossible? If so, where can I get a thermo switch or sending unit that has same thread size as stock thermo switch? Last edited by jafero; 02-26-2007 at 08:34 AM..

02-26-2007, 03:52 AM	#2
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	Oh boy. You need a fan controller. The thermo switch has 2 wires because it measures resistance as a function of temperature change. The fan has 1 wire because it needs to see 12V (+) to draw power. A relay triggers a large current when it sees a small current. How can the thermo switch possibly trigger a relay when the thermo switch doesn't have current flowing through out? http://www.frsport.com/DIF_Dual_Fan_...40SX_t_22.html

02-26-2007, 08:41 AM	#5
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	Sorry to confuse you. I meant the thermo switch, not the thermostat. There are two thermoswitches in the car and the one located by the coolant bleeder hole monitors the water temp for the ecu, as far as I know.

02-26-2007, 09:03 AM	#6
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 51 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	The 2pin sender is for the ECU, the single pin is for the OE gauge. You can replace it with an aftermarket sender since the OE guage is crap.

02-26-2007, 09:32 AM	#7
jafero Leaky Injector Join Date: Jun 2006 Location: NJ Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	Thanks! You know any aftermarket sender that have same thread size with the stock thermoswitch?