Electric fan temp switch - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-15-2013, 09:34 PM
Registered User
 
Last photo:
Join Date: May 2012
Posts: 289
Wiki Edits: 0

Thanks: 5
Thanked 5 Times in 5 Posts
Electric fan temp switch

Ok. I baffled. I have my electric fan wired through a temperature switch. On at 195 of at 185. I just built the motor and when I fired it for the first time the fan didn't come on so I pulled the 2 wires from the switch and jumped them together and it comes on so I figured the switch must be hooped. I replaced the switch with a new one but the fan is still not coming on. I tested both switches and they are both defianlty working. The switch is located in the passanger side cylinder head and the temperature sender is in the other head. Ill run the motor till it reaches about 220 degrees. When the fan doesn't come on I pull the wires of the swith and jump them. The fan comes on and the temp quickly drops to about 190. When I pulled the switch water poured out of the head.

Any thought?

    Advertisement

Last edited by prostcelica; 01-15-2013 at 09:39 PM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-15-2013, 11:00 PM
Registered User
 
Last photo:
Join Date: May 2012
Posts: 289
Wiki Edits: 0

Thanks: 5
Thanked 5 Times in 5 Posts
I should add that nothing has changed (ie wiring wise) since I installed the new motor. I pulled the old one and put the new one in. I only diconected the wires required to pull the motor and then hooked everything back up to the motor the same way. The fan ( with the temp switch) work great with the old motor.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-16-2013, 06:07 AM
Registered User
 

Last journal entry: 50 Ply wagon
Last photo:
Join Date: Oct 2008
Location: Pottstown,Pa
Posts: 624
Wiki Edits: 0

Thanks: 0
Thanked 30 Times in 29 Posts
Not positive on this answer but it may be the computer. The computer answers to all the sensors . One sensor may be on its way out.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-16-2013, 08:38 AM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 64
Posts: 1,054
Wiki Edits: 0

Thanks: 1
Thanked 21 Times in 18 Posts
[/IMG]http://
I hope you are running a 30 amp automotive relay
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-16-2013, 08:42 AM
Irelands child's Avatar
Registered User
 
Last wiki edit: Ford engine specifications Last photo:
Join Date: Jan 2005
Location: Upstate New York
Posts: 4,903
Wiki Edits: 8

Thanks: 13
Thanked 200 Times in 181 Posts
I am 'assuming' that this is a non-computer engine, but if it is - oh well!!

These temp senders are grounded, that is, complete the circuit through the actual fitting itself when they heat up(usually a bimetallic component). If you have used a sealer on the fitting or even any adapters to ensure no leaks, they wont work. When you touch the wires together, you will complete the circuit. Oil pressure senders work electrically in a similar fashion as far as completing a circuit.
__________________
Irelands child
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-16-2013, 08:53 AM
NEW INTERIORS's Avatar
Believe in yourself !!!!!!
 

Last journal entry: 41 WILLYS FRAME
Last photo:
Join Date: Jul 2007
Location: In My Shop..
Age: 49
Posts: 10,057
Wiki Edits: 0

Thanks: 1,210
Thanked 529 Times in 393 Posts
Quote:
Originally Posted by Irelands child View Post
I am 'assuming' that this is a non-computer engine, but if it is - oh well!!

These temp senders are grounded, that is, complete the circuit through the actual fitting itself when they heat up(usually a bimetallic component). If you have used a sealer on the fitting or even any adapters to ensure no leaks, they wont work. When you touch the wires together, you will complete the circuit. Oil pressure senders work electrically in a similar fashion as far as completing a circuit.
Very true.. No sealer on the senders..They will not make the ground they need..
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-16-2013, 09:01 AM
Registered User
 
Last photo:
Join Date: May 2012
Posts: 289
Wiki Edits: 0

Thanks: 5
Thanked 5 Times in 5 Posts
Motor is a 70's SBC so no computor. Yes I am running a relay and have it wired like the attached diagram in the previous post. I did have teflon tap on the fitting but I had teflon tape on it before. Ill try it with out the tape but I'm not sure that's it (correct me if I'm wrong please) as when the switch heats up and completes the circuit it allows it to go to ground(doesn't groung to the motor. 2 wires of the switch one goes to ground on the relay the other goes to ground on the frame.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-16-2013, 09:16 AM
Irelands child's Avatar
Registered User
 
Last wiki edit: Ford engine specifications Last photo:
Join Date: Jan 2005
Location: Upstate New York
Posts: 4,903
Wiki Edits: 8

Thanks: 13
Thanked 200 Times in 181 Posts
Quote:
Originally Posted by prostcelica View Post
Motor is a 70's SBC so no computor. Yes I am running a relay and have it wired like the attached diagram in the previous post. I did have teflon tap on the fitting but I had teflon tape on it before. Ill try it with out the tape but I'm not sure that's it (correct me if I'm wrong please) as when the switch heats up and completes the circuit it allows it to go to ground(doesn't groung to the motor. 2 wires of the switch one goes to ground on the relay the other goes to ground on the frame.
Usually/normally there is a +12VDC to one side of that switch with the body grounded. The switch heats the element, closes the circuit, allowing the 12VDC to flow to the, in this case, the relay. Think of a home light switch. The black wire is hooked to one terminal while the white continues on to the receptacle. Flip that switch on, you then complet the circuit - exactly what you are doing when you jumper the two wires together as you noted above. The body of the temp switch acts like the white wire in the house switch (forget about the bare wire, that's a 'safety valve' and something that wasn't even present until the late '60/'70s) Tape, thread sealer, etc - wont allow the circuit to work (an insulator)
__________________
Irelands child
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-16-2013, 09:30 AM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 64
Posts: 1,054
Wiki Edits: 0

Thanks: 1
Thanked 21 Times in 18 Posts
You can use thread sealer tape. Just cover a small portion of the thread. The exposed thread will connect to the head or manifold.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-16-2013, 11:04 AM
ogre's Avatar
the 'Duracell Project'
 
Last photo:
Join Date: Nov 2009
Location: Motown
Posts: 1,389
Wiki Edits: 0

Thanks: 0
Thanked 100 Times in 90 Posts
i've never used teflon tape on an electrical sensor, teflon is an insulator
use pipe dope it will mush out of the way and ground thru the threads
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-16-2013, 12:02 PM
Registered User
 
Last photo:
Join Date: Jan 2006
Location: Nanaimo, B.C., Canada
Posts: 671
Wiki Edits: 0

Thanks: 3
Thanked 18 Times in 18 Posts
I know the switch he is using and it has 2 terminals, not 1. 1 terminal is attached to ground, so I don't think the switch itself has to be grounded. There should be power to one side of the switch however.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electric fan temp ? zeke5 Hotrodding Basics 10 01-14-2013 05:09 AM
electric fan temp switch g.m. stich626 Electrical 6 01-28-2012 06:21 AM
Temp switch for electric fan solidaxel Electrical 2 03-05-2005 12:31 PM
electric fan temp switch probe, problem 39chevy Electrical 3 08-07-2004 07:28 PM
electric fan (Adjustable temp switch) QUESTION 39chevy Electrical 0 06-16-2004 07:54 PM


All times are GMT -6. The time now is 09:05 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.