Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

A list of 924 Thermoswitches and what they do...

 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
Mkol  



Joined: 04 Aug 2023
Posts: 27
Location: uk

PostPosted: Sat Jan 13, 2024 12:16 am    Post subject: A list of 924 Thermoswitches and what they do... Reply with quote

Hi guys as i continue with the restoration of my 1979n/a im trying to grapple with all the operations of the various Thermoswitches/sensors and their function. Would someone be kind enough to take a look at the below and correct me if i am way off?
or just any additional info welcome!




Thermo-time switch (located in the rear coolant flange mounted to the head)
Purpose: operates the cold start injector by providing ground for an amount of time when ignition is in ‘start’ position.



Thermoswitch (small one mounted just below Thermo-time switch also in rear coolant flange)
Purpose: Provides a warning to the dashboard gauge or light, is this a sensor or a switch??




Thermoswitch. (Mounted on a T piece inline on the transfer tube towards rear coolant flange.
Purpose; Operates the HOT START valve which is next to the fuel distributor





Thermoswitch (mounted on radiator)
Purpose: to switch on cooling fan when coolant reaches a set temperature.
Back to top
View user's profile Send private message
924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Sat Jan 13, 2024 1:50 am    Post subject: Reply with quote

I can't speak to the third, but correct on #1 and #4. #2 is a temp sensor, not a switch, to give the reading on the dash/gauge.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
morghen  



Joined: 21 Jan 2005
Posts: 8868
Location: Romania

PostPosted: Sat Jan 13, 2024 3:42 am    Post subject: Reply with quote

That second one with only one wire connection is the coolant temp that shows the temp in the dash. The rest are termo switches.
_________________
https://www.the924.com
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Mkol  



Joined: 04 Aug 2023
Posts: 27
Location: uk

PostPosted: Sun Jan 14, 2024 6:29 pm    Post subject: Reply with quote

Thanks for clarifying guys, can anyone shed any more light on the function of the 3rd one? Mine doesn’t appear to work. Does anyone know what temp it activates and whether it’s off at cold or vice versa etc..?
Back to top
View user's profile Send private message
morghen  



Joined: 21 Jan 2005
Posts: 8868
Location: Romania

PostPosted: Sun Jan 14, 2024 9:16 pm    Post subject: Reply with quote

The hot start thermo switch becomes conductive when over a certain temp, providing ground to the hot start valve.
The hot start valve influences the control pressure if i remember correctly and makes the starting of the car easier when hot.
I dont know the values, but put it in hot water and mesure for conductivity.
_________________
https://www.the924.com
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Sun Jan 14, 2024 11:47 pm    Post subject: Reply with quote

Agreed; I would guess somewhere over 70C should be enough to get it to close...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 10 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group