Sniper electric fan wiring - Ford Mustang Forum
 
LinkBack Thread Tools
post #1 of 6 (permalink) Old 01-11-2020 Thread Starter
GT Member
 
Charles Reeves's Avatar
 
Joined: Sep 2010
Location: Knoxville
Posts: 1,472
 
Sniper electric fan wiring

I'm attaching a drawing for this, in case it might be useful to some. I got the info from a Holley instruction sheet that comes with their fan wiring kit, basically a relay and some wires. I already had a box of relays. The wiring colors on the drawing are for my setup; others may differ. The concept of switching the relay with ground rather than +12 is really strange to me. I'm guessing it has to do with how the EFI controller internals work.

Attached Thumbnails
Click image for larger version

Name:	Electric fan Sniper wiring.jpg
Views:	22
Size:	200.9 KB
ID:	612859  
Charles Reeves is online now  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 01-11-2020
SHELBY GT 350 Member
Classic Member
 
Ivy66GT's Avatar
 
Joined: Dec 2008
Location: Albuquerque
Posts: 7,964
 
Switching on the ground side doesn't make any difference, either way works. Italians seemed to prefer ground side switches long before EFI was invented. The best thing for EFI would be a diode across the relay coil to reduce electrical noise and your drawing shows none.

Ivy66GT is offline  
post #3 of 6 (permalink) Old 01-12-2020 Thread Starter
GT Member
 
Charles Reeves's Avatar
 
Joined: Sep 2010
Location: Knoxville
Posts: 1,472
 
Good point. I had one on the relay for my old electric fuel pump, and just didn't think about it for this one. Will add it. Strange that the Holley instructions for their Sniper fan relay kit does not mention a diode.

I'm now wondering if the fuel pump relay that comes with the Sniper has one. Thanks.

Last edited by Charles Reeves; 01-12-2020 at 10:37 AM. Reason: Added Holley instructions comment
Charles Reeves is online now  
 
post #4 of 6 (permalink) Old 4 Weeks Ago
SHELBY GT 350 Member
Classic Member
 
Ivy66GT's Avatar
 
Joined: Dec 2008
Location: Albuquerque
Posts: 7,964
 
Might be. Measuring both directions with an ohmmeter will tell you if there is a diode inside.
Ivy66GT is offline  
post #5 of 6 (permalink) Old 4 Weeks Ago Thread Starter
GT Member
 
Charles Reeves's Avatar
 
Joined: Sep 2010
Location: Knoxville
Posts: 1,472
 
Holley says no diode needed

I asked them if one was needed and got the following response.

Hi Charles, thanks for contacting Holley Performance Products.

If you are using a trinary switch to where AC turns on fans as well a diode is needed. If you are just controlling fans only no diode is necessary.

Thanks
Nathan G
Charles Reeves is online now  
post #6 of 6 (permalink) Old 4 Weeks Ago
SHELBY GT 350 Member
Classic Member
 
Ivy66GT's Avatar
 
Joined: Dec 2008
Location: Albuquerque
Posts: 7,964
 
That may be true for the fans since they don't care about noise. But without a diode you generate a lot of RF noise when you switch off any motor. If you have nothing that is bothered by the noise then no one cares. The 'E' in EFI implies electronics which may not like extra noise.
Ivy66GT is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1