testing vss wire
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=125388
Printed Date: May 11, 2024 at 12:51 AM
Topic: testing vss wire
Posted By: resquchas
Subject: testing vss wire
Date Posted: January 01, 2011 at 1:41 PM
how to you know if you have the correct VSS wire. Is there a danger of getting the wrong one? Tach makes sense, because if you start the motor and rev it you see a change on DMM( I read the AC vs DC argument awhile back, whew, you guys are geniuses)
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The RIGHT way is the ONLY way.
Replies:
Posted By: i am an idiot
Date Posted: January 01, 2011 at 2:46 PM
You check for VSS the same exact way. It is a pulsating DC voltage, depending on the quality of your meter, it may only register on one or the other, AC/DC, but one will show an increase in voltage the faster the car is driven. Tag the wire and have someone drive the vehicle while you watch the meter.
Posted By: howie ll
Date Posted: January 01, 2011 at 3:36 PM
Be careful doing this but it should start reading after about 1.5 mph. What vehicle and year please.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: howie ll
Date Posted: January 01, 2011 at 3:39 PM
At last, some one who asks sensible questions.
Once tried to find this on a Jaguar, did it static with the car jacked up, only to find the anti slip kept cutting in...doh.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: resquchas
Date Posted: January 01, 2011 at 3:41 PM
that makes sense guys thanks. So if alone then you just have to go by a wiring diagram or, do a check in parking lot( safely) If I do not see the DMM signal I want then, try another.
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The RIGHT way is the ONLY way.
Posted By: howie ll
Date Posted: January 01, 2011 at 6:05 PM
It's probably not needed, most current Sat Nav head units don't need it.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: i am an idiot
Date Posted: January 01, 2011 at 6:47 PM
I agree with Howie, the only time any reputable brand unit uses the VSS is when it loses GPS signals. The only time it is needed is in parking garages or tunnels. The nav unit has a magnetic compass and it uses the VSS to kind of keep track of your location until GPS signal is obtained, then it will correct your exact location.
Posted By: howie ll
Date Posted: January 01, 2011 at 6:54 PM
Also modern units have gyros and extremely good software that recognises the vector from the gyroscopes, coming out of a tunnel nowadays, it takes about 2 seconds to regain its position.
Couple of years ago that would have been 2 mins.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: resquchas
Date Posted: January 01, 2011 at 8:11 PM
I think a 2 second refresh period is very acceptable. Would or do alarm/RS systems make use of VSS wire for convenience features like automtic door locking upon motion. I do not know what that would do at a stop light though unless the unlock is upon removing key... just curious.
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The RIGHT way is the ONLY way.
Posted By: howie ll
Date Posted: January 02, 2011 at 4:27 AM
Clifford G5 and I believe Compustar use tach sensing for RPM/engine load not speed dependant locking.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: tedmond
Date Posted: January 02, 2011 at 9:16 AM
compustar uses the tach for 2 purposes.
by default it is used for crank settings so it doesnt overcrank, the second option that can be turned on is for the RPM sense lock. Once the rpm reaches double (of the programmed tach) it will lock the doors.
for example if the tach is programmed at 900 rpm, at 1800rpm the doors lock. ------------- Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert
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