Question about 1997 Chevrolet Blazer

2 Answers

Voltage drop test

How do I conduct th voltage drop test?

Posted by on

  • hbolstad Sep 01, 2008

    Actually figured it out. I had the ignition wire hooked up as a ground instead of a hot wire.... dumb miastake but atleast it starts now. Thanks for all the help.

×

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 169 Answers

A voltage drop test is done using a DVOM. Set the meter to the DC voltage scale. Depending on the side of the cicuit you are on, place the positive lead on the most positive end of the cable.(closest to the positive terminal) and the negative on the other side of your cable/connection.Then exercise it. ( IE: Turn the headlight switch when checking voltage drop across the ground). The meter should read as close to zero volts as possible. (acceptable to rise up to 0.03v on the ground side) The reading you get is the amount that the cable or connection you are checking is drawing from your 12v source. You should do this to check for concerns in a circuit, so do not clean the connections until you perform the test.I hope this is helpful, if you need more info., drop me a line.

Posted on Aug 31, 2008

  • Chuck Finn
    Chuck Finn Sep 01, 2008

    Sorry emissionwiz and hbolstad, didn't mean to upset anyone. You asked how to run a voltage drop test, I was just trying to help. The test you are performing is just a voltage test,not a voltage drop test.Again, didn't mean to ruffle feathers,just trying to help.

×

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

  • Chevrolet Master
  • 61,037 Answers

Go to the far end of the cable and make sure the voltage is the same as the other end, clean the cable ends first.

Posted on Aug 31, 2008

  • 1 more comment 
  • yadayada
    yadayada Sep 01, 2008

    Don't pay any attention to the other guy saying not to clean the cables first, clean them and test the voltage at the starter end at the starter terminal.

  • yadayada
    yadayada Sep 01, 2008

    The reason I suggested the test I described was to eliminate the kind of issue I have seen often, the cable looks good at battery end, but acid has gotten inside the insulator and there is no connection going to the starter, I look forward to your further input AutoDoc, every tech has his or her way of doing things, I do know how to run a true voltage drop test, but that may be a little confusing for a shade tree mechanic.

  • Alicia Jun 18, 2013

    any idea as to how to perform a voltage drop test across the injectors?

×

1 Suggested Answer

emissionwiz
  • 61037 Answers

SOURCE: voltage drop test

First, check battery post to cable connection: positive meter lead on battery positive post, negaitve lead on battery's positive cable clamp. Crank the engine and note the reading. A good connection should have zero voltage drop. Second, check the positive cable: positve meter lead on positive battery clamp, negative lead on starter terminal connector. A good cable will show a voltage drop of .2 volts or less while cranking. Third, check the starter connection: positive meter lead on positive battery terminal on the solenoid, negative meter lead on actual starter stud. A good connection will have a voltage drop of near zero volts. Now to check the negative side of the circuit. Total drop on the ground side should be .3 volts or less and can be checked by placing positive meter lead on starter housing and negative meter lead on battery ground post. Take your reading while cranking the engine, and be sure your connection at the starter is solid and clean. If total voltage drop on this side of the circuit is excessive, complete testing at all connections in the same fashion as the positive side of the circuit. Check the following: between battery post and clamp (zero voltage drop), cable end at battery to cable end at engine. (.2 volts or less), cable end at engine to engine itself (near zero voltage drop), and finally between starter housing and engine block (.1 volts or less).

To read the entire procedure for all automotive systems read this artile:
http://www.engine-light-help.com/voltage-drop.html

Posted on Sep 01, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Kia Sedona does not start


Battery cables could cause this problem . To test the starter circuit we do voltage drop testing with DVOM - digital volt ohm meter . Corrosion can get down inside the battery cables an cause a drop of voltage in the circuit . Starter Voltage Drop

Sep 30, 2016 | 2004 Kia Sedona EX

1 Answer

Intermittent problem - speed dial 'drops out' sometimes for a few seconds, sometimes for a couple of minutes, then returns to normal operation


What year an model ford ? Electronic module clinch , lose or corroded connector or wiring , ground wiring etc... Do you know what voltage drop testing is ? Voltage drop test main battery cables , What is Voltage Drop Voltage testing fundamentals Mastering Voltage Drop Testing with Pete Meier and Jerry Truglia

watch these videos


Sep 09, 2016 | Ford Focus Cars & Trucks

1 Answer

Blowing headlight bulbs three to four times a year


There is probably corrosion in the circuit causing resistance . Do a voltage drop test on the circuit . On youtube you will find a lot of videos on voltage drop testing . Voltage drop testing will catch automotive electrical thieves

Dec 23, 2015 | 2004 Hyundai Elantra

2 Answers

Voltage drops when setting still has new battery and alternator


Check grounds. Look at your cables. Could be corrosion.

Oct 30, 2015 | Cars & Trucks

2 Answers

1985 GMC Sierra Classic has battery charge but dies out with single click. My battery needed a jump the other day. Drove truck for 2 days. When I went to start it began to turn over then died. I tried...


the battery is probably bad, one way to test it is conduct a load test. Hook a voltage meter to the battery post and have someone try to start the truck. If the voltage drops below 10.4 volts DC, replace the battery.

Sep 17, 2014 | Cars & Trucks

1 Answer

Why wont car start


Try a line drop test on the circuit. Sometimes wire can deteriorate to the point that it will conduct Voltage, but will no longer sustain the amp load to run the starter. If you find the line set to be within range, replace the ignition switch in the lower end of the column.

Jul 11, 2014 | 2006 Chrysler 300

1 Answer

Our Grand voyager regularly will not start. we are told it is not the battery. The electrics seem to be able to turn themselves on at 22 C, even if we turn them off. we then turn the key and it just...


This is a basic case of your battery and charging system needs to be PROPERLY tested.

First, the battery: If the machanics that you went to checked the battery with an old-school carbon-pile battery tester, this is not good enough for today's batteries used in today's high-tech cars. The battery should be tested with a tester that checks the conductivity of the battery. This is the only sure way to detect a sulfated or partially shorted cell. I have seen many batteries that pass the old carbon-pile test and fail miserably when conductivity is checked.

Battery Cables: The battery cables should be tested for voltage drop. This is the ONLY way that you can be sure the cables are in good condition and are connected properly. The POSITIVE cables should be checked for voltage drop between the battery and the starter as well as between the battery and the main fuse block under the hood. The NEGATIVE cables should be checked for voltage drop beween the battery and the engine block and from the battery to the body. The maximum allowable voltage drop with the cables loaded (headlamps on, blower motor on high) is 300 milivolts (0.3 volts) for the POSITIVE cables and 200 milivolts (0.2 volts) on the NEGATIVE cables. (most will have MUCH less voltage drop than this.)

Alternator: Again, old shool is not good enough. Alternators are regularly tested only by checking charging system voltage at idle. It should be between 13.7 and 14.3 volts. However, this is not the complete picture. A charging system tester should be used that can apply a measured load to the battery while checking the charging system voltage at an engine speed of 2000 RPM. This can detect things like weak alternator diodes or weak/loose connections in the alternator circuit. AC ripple should also be checked to make sure that the diodes in the alternator are not allowing an excessive amount of AC current to get to your battery.

If any problems are found in any of the tests above, these must be fixed before any further diagnosis can be performed.

Then there is the Ignition-Off Draw test. To put it simply, this test measures how muchcurrent is being drained from your battery with the ignition turned OFF, using either an inductive or in-line ammeter. Some draw is perfectly normal due to computer memory, radio station settings memory, etc.. The absolute maximum allowable draw with the ignition OFF is 300 miliamps (0.3 Amps) Most vehicles that I have tested are normally below 100 milliamps.

Although there could be a bunch more time needed to track down the actual source of a draw on the battery, the entire charging system and ignition off-draw tests listed above can be performed by a mechanic that is worth his salt in 1/2 hour (assuming we are talking about a properly equipped shop). So don't let anyone gouge you for excessive diagnostic time just for perfoming these tests and reporting back to you. Or to put it another way, within 1/2 hour they should be able to tell you which of these tests your vehicle failed and if more diagnostic time is needed, they should be able to give you a REAL GOOD reason WHY.

Dec 30, 2011 | Cars & Trucks

1 Answer

Voltage drop test


First, check battery post to cable connection: positive meter lead on battery positive post, negaitve lead on battery's positive cable clamp. Crank the engine and note the reading. A good connection should have zero voltage drop. Second, check the positive cable: positve meter lead on positive battery clamp, negative lead on starter terminal connector. A good cable will show a voltage drop of .2 volts or less while cranking. Third, check the starter connection: positive meter lead on positive battery terminal on the solenoid, negative meter lead on actual starter stud. A good connection will have a voltage drop of near zero volts. Now to check the negative side of the circuit. Total drop on the ground side should be .3 volts or less and can be checked by placing positive meter lead on starter housing and negative meter lead on battery ground post. Take your reading while cranking the engine, and be sure your connection at the starter is solid and clean. If total voltage drop on this side of the circuit is excessive, complete testing at all connections in the same fashion as the positive side of the circuit. Check the following: between battery post and clamp (zero voltage drop), cable end at battery to cable end at engine. (.2 volts or less), cable end at engine to engine itself (near zero voltage drop), and finally between starter housing and engine block (.1 volts or less).

To read the entire procedure for all automotive systems read this artile:
http://www.engine-light-help.com/voltage-drop.html

Aug 31, 2008 | 1997 Chevrolet Blazer

Not finding what you are looking for?
1997 Chevrolet Blazer Logo

Related Topics:

428 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

60960 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6812 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...