4.0 swap/VSS wiring - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > 4.0 swap/VSS wiring

Jeep Liberty Wheel Bearing & Hub - FrontSAVE BIG: Christmas in July Sale!Jeep Liberty Window Regulator

Reply
Unread 04-21-2012, 08:05 AM   #1
ymurf
Registered User
1979 CJ7 
 
Join Date: Apr 2011
Location: Steelville, Mo
Posts: 740
4.0 swap/VSS wiring

I put a 94 4.0 from a YJ in my 78 CJ7 with the AX15 and a Dana 300. I bought a 91 YJ Speed sensor and it has a two wire hook up.The wiring for the Speed sensor from the 94 4.0 has three wires. I bought the 3 to 2 wire conversion plug from Hesco..Which two out of the three do I hook up?

ymurf is offline   Reply With Quote
Unread 04-21-2012, 09:16 AM   #2
1986cj
Registered User
1986 CJ7 
 
Join Date: Dec 2007
Location: Denver Colorado
Posts: 1,873
I have copied this from cjoffroad, never tired it but guys say it works. The Early 2 wire VSS is a simple mechanical switch, it makes and breaks a set of contacts internally using magnets and a reed switch. One wire is from the PCM which has a 5 volt reference internally, the other is the sensor return. When the 5 volts drops to ground, the PCM senses a trigger.

The later 3 wire VSS uses a Hall effects switch to make and break the connection between the sensor return wire and the ground wire. The 3rd wire is a 5-8 volt power supply to operate the hall effect sensor.

The 3 wire sensor colors are usually:
Wt/Bk = 5-8v supply
Wt/Or = Sensor return (signal to PCM)
Bk/LB = Common sensor Ground

With the 2 wire sensors, just connect the 2 wires to the Bk/LB and Wt/Or wires from the harness, you can disregard the Wt/Bk = 5-8v supply wire, it's not needed! It doesn't even matter which wire you connect to which pin on the 2 wire VSS, (but if the colors match, connect them!)

Hope this helps!
1986cj is offline   Reply With Quote
Unread 04-21-2012, 12:54 PM   #3
ymurf
Registered User
1979 CJ7 
 
Join Date: Apr 2011
Location: Steelville, Mo
Posts: 740
Quote:
Originally Posted by 1986cj View Post
I have copied this from cjoffroad, never tired it but guys say it works. The Early 2 wire VSS is a simple mechanical switch, it makes and breaks a set of contacts internally using magnets and a reed switch. One wire is from the PCM which has a 5 volt reference internally, the other is the sensor return. When the 5 volts drops to ground, the PCM senses a trigger.

The later 3 wire VSS uses a Hall effects switch to make and break the connection between the sensor return wire and the ground wire. The 3rd wire is a 5-8 volt power supply to operate the hall effect sensor.

The 3 wire sensor colors are usually:
Wt/Bk = 5-8v supply
Wt/Or = Sensor return (signal to PCM)
Bk/LB = Common sensor Ground

With the 2 wire sensors, just connect the 2 wires to the Bk/LB and Wt/Or wires from the harness, you can disregard the Wt/Bk = 5-8v supply wire, it's not needed! It doesn't even matter which wire you connect to which pin on the 2 wire VSS, (but if the colors match, connect them!)

Hope this helps!
Thats better than anything else I have found..Mine has an orange,A white with orange stripe and a black with blue stripe.So I am guessing I would disregard the orange wire?? Anyone else agree?
ymurf is offline   Reply With Quote
Unread 04-21-2012, 01:06 PM   #4
1986cj
Registered User
1986 CJ7 
 
Join Date: Dec 2007
Location: Denver Colorado
Posts: 1,873
If I remerber right may have been from Marty So Cal, but not real sure. He hangs out over on priate and is real good with mpfi. The way I understand it is "you can disregard the Wt/Bk = 5-8v supply wire, it's not needed!"
Take a volt meter and see witch one has 5-8v and dont use it.
1986cj is offline   Reply With Quote
Unread 04-21-2012, 01:11 PM   #5
ymurf
Registered User
1979 CJ7 
 
Join Date: Apr 2011
Location: Steelville, Mo
Posts: 740
Quote:
Originally Posted by 1986cj View Post
If I remerber right may have been from Marty So Cal, but not real sure. He hangs out over on priate and is real good with mpfi.
I made a post over there this morning but no response.
ymurf is offline   Reply With Quote
Unread 08-03-2012, 04:04 PM   #6
Jak_Flash
Registered User
 
Join Date: Oct 2009
Location: Canada
Posts: 3
Is the 2 wire hookup from the 91 vss considered a 2 pole vss? I'm in need of one for my 5.7tbi swap.
Jak_Flash is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.