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ohms anyone? working on a 2004 Impala

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=35088
Printed Date: May 19, 2024 at 10:19 AM


Topic: ohms anyone? working on a 2004 Impala

Posted By: Fosgate3
Subject: ohms anyone? working on a 2004 Impala
Date Posted: July 05, 2004 at 6:21 PM

Okay... I feel really stupid for asking this...

I'm using a Blue Point DMM and I am checking the resistance of two wires on a car I am working on. The DMM has several settings: Continuity (inaudible), Audible Continuity (beeps when you make contact), a setting called "200", a setting called "20k", a setting called "200k", a setting called "20M", and a setting called "200M". I have never used any setting other than the audible continuity setting. what are the others for?

How this relates to car security: I am working on putting in a Harada 900 Remote Start system on a 2004 Impala. A few other old installer friends of mine explained to me how a module is not needed on this car and how you can do the remote start by finding the 3 18guage wires to go to the key... a black, a yellow, and a white wire. What you do is remove the insulation from the black wire (don't cut it, just get some bare wire showing) and touch one of your DMM leads to that. Cut the Yellow Wire and put the other DMM lead to the key side of that wire. Put the car in Neutral or Reverse and turn over (it wont start of course). The resistence will be displayed on the DMM. Get a resistor that equals that ohm load and solder it to the IGNITION side (not the key side but the other side) of the yellow wire and then to the bare spot on the black wire. When doing that, you will be feeding the resistance from the key at all times and your remote start will work fine.

The problem I was having was that I think my DMM is smarter than me. I used what I thought was my lowest setting (the continuity setting) but I am getting .446  ohms... should I move the decimal point over or something? should it be 446 ohms?

I was also given a great shortcut on the locks in this car. no modules needed and only two relays.




Replies:

Posted By: spl-Hz
Date Posted: July 05, 2004 at 7:04 PM

 Sounds like you will permanently disable the pass lock system. This might not be healthy for computer. I normaly use an interface called a PL-data . This hooks up at the purple wire at  data entry plug under dash drivers side.  This unit will learn the resistance and not defeat pass lock. I think you are reading your meter correctly .446 is 466 ohms.





Posted By: Fosgate3
Date Posted: July 05, 2004 at 7:10 PM

so .446 = 446 ohms... here is the DMM that I have: https://buy1.snapon.com/catalog/pro_det.asp?P65=yes&qt=1&qty=1&Item_id=16690&PartNo=EEDM503B&Price=126.20&ListPrice=126.20&FORMNAME=1&Desc=Multimeter%2C+Digital%2C+Advanced%2C+Non-Auto-Ranging&SUB_Cat_ID=&SUB_Cat_NAME=&Cat_ID=&Cat_NAME=&group_id=1369&group_NAME=Digital+Multimeters

My friends work at the local stereo shop and have been doing these cars like this for some time. They haven't had any problems that they've expressed to me.

Thanks for the input





Posted By: Fosgate3
Date Posted: July 05, 2004 at 9:26 PM
will do. thanks!




Posted By: jherrick
Date Posted: July 20, 2004 at 6:56 PM

I feel I must step in here.  Your DMM (digital multimeter) is a non-autoranging meter, according to the website.  With these multimeters, the numbers listed are the range of operation.  For example, in the Ohms/resistance section 200 means that the meter will read from 0 to 200 Ohms, but anything above that will give you an error message, probably OR (over range) or something similar.  The K after the number stands for thousand.  So 20K means that if something is between 200 and 20,000 Ohms you should use this range to get an accurate reading.  It will read less ohms/resistance, but will not be as accurate if you are trying to measure something with low resistance.

Continuity is not meant for reading a value, but is normally a pass/fail type of measurement.  Resistance is the measure of the effort that it takes for the current to travel through a component.

So to properly measure the resistance of a component that is supposed to have 446 Ohms, use range 20K, as bobk said, and the meter should read 446.





Posted By: Fosgate3
Date Posted: July 20, 2004 at 6:59 PM
Thanks for stepping in. I ended up figuring the DMM out... i felt like an idiot posting this on here but I really never used the DMM outside of ohms on speakers. It turned out the Passlock Key was doing about 470ohms. I got the resistors soldered up and the remote start works like a charm.





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