Cool resource on testing auto electrical systems...

Stumbled across this while searching for something else...

"Testing Electrical Systems with a Digital Multimeter

"Perhaps the most important tool you'll use in troubleshooting auto electrical
systems is the multimeter. Basic multimeters measures voltage, current and
resistance, while more elaborate multimeters, such as the Fluke 78, or Fluke 88
have featues that can check things such as frequency, duty cycle, dwell, make
diode tests, and even measure temperature, pressure and vacuum."

http://assets.fluke.com/appnotes/automotive/beatbook.pdf

Of course, they list Fluke meters, but most tests will work with any DMM.

 

Those two meters are more or less an old school automotive tool that serve as
better then having nothing kind of tool for automotive repair now days.
Repairing cars now days without a good scan tool is a waste of money and time
and even more so if you have a good scan tool not know how to use it.

 

Those two meters are more or less an old school automotive tool that serve as
better then having nothing kind of tool for automotive repair now days.
Repairing cars now days without a good scan tool is a waste of money and time
and even more so if you have a good scan tool not know how to use it.

 

Thanks matt, really useful..

 

Thanks matt, really useful..

 

As somebody who isn't old-school at heart (I've been DIYing for nearly 40
years but have worked on my own Toyota hybrids for four years now), I still
get a lot more use out of a voltmeter than out of a scantool. Scantools are
indispensable for retrieving codes, so there is a clear need for them, but
once that is done the tool is set aside. Then comes the work of figuring out
just what the codes are trying to tell you. Relatively few are as direct as
"VSS sensor failed"; hunting down a "multiple cylinder random misfire" is
more typical. The most frustrating intermittent I've faced in recent years
was my Nissan that suffered sudden ignition failure for a few seconds to a
few minutes half a dozen times a day for two months. The ECU said,
"Everything's okay! Keep driving, boss!" It was a voltmeter that found the
problem (intermittent connection on the low side of the ignition coil, so no
voltage to ignitor) when it stayed bad long enough. But the ECU told me that
everything it knew about was normal, so I looked past the ECU's reach.

The value of a voltmeter is in the wide reach of the automotive electrical
system. A DVM will tell you whether your charging system is working right or
not, whether you have an open or shorted circuit in your fan or lights or
door locks, whether the engine temperature or oil pressure sensor is
actually bad. If nothing happens when you try to start the car and the
lights won't even come on, a voltmeter is what you want. You might as well
leave the scantool on the shelf, because it won't do anything.

My point is that more tools are needed than ever. Scantools are some of the
latest in the goody bag and every wrench should have access to one. I'd say
the same of an oscilloscope, but that's a little harder core. Voltmeters -
particularly DVMs - are still absolutely indispensable to any
troubleshooter.

Mike

 

As somebody who isn't old-school at heart (I've been DIYing for nearly 40
years but have worked on my own Toyota hybrids for four years now), I still
get a lot more use out of a voltmeter than out of a scantool. Scantools are
indispensable for retrieving codes, so there is a clear need for them, but
once that is done the tool is set aside. Then comes the work of figuring out
just what the codes are trying to tell you. Relatively few are as direct as
"VSS sensor failed"; hunting down a "multiple cylinder random misfire" is
more typical. The most frustrating intermittent I've faced in recent years
was my Nissan that suffered sudden ignition failure for a few seconds to a
few minutes half a dozen times a day for two months. The ECU said,
"Everything's okay! Keep driving, boss!" It was a voltmeter that found the
problem (intermittent connection on the low side of the ignition coil, so no
voltage to ignitor) when it stayed bad long enough. But the ECU told me that
everything it knew about was normal, so I looked past the ECU's reach.

The value of a voltmeter is in the wide reach of the automotive electrical
system. A DVM will tell you whether your charging system is working right or
not, whether you have an open or shorted circuit in your fan or lights or
door locks, whether the engine temperature or oil pressure sensor is
actually bad. If nothing happens when you try to start the car and the
lights won't even come on, a voltmeter is what you want. You might as well
leave the scantool on the shelf, because it won't do anything.

My point is that more tools are needed than ever. Scantools are some of the
latest in the goody bag and every wrench should have access to one. I'd say
the same of an oscilloscope, but that's a little harder core. Voltmeters -
particularly DVMs - are still absolutely indispensable to any
troubleshooter.

Mike

 

Thanx.


--

Let the unseen day be. Today is more than enough.

___Sador the carpenter to Turin
Tolkien, The Unfinished Tales

Ellis_Jay

 

Thanx.


--

Let the unseen day be. Today is more than enough.

___Sador the carpenter to Turin
Tolkien, The Unfinished Tales

Ellis_Jay