# Multi-Meter Lesson's i need some



## cajunh2s (Apr 19, 2007)

Does anyone happen to have a link with some walk through's are proper precedure's on how to check out an electrical system and correct settings to use with a multi meter?......

here's my dilema....been toying with a murray riding lawn mower one of my neighbors threw out to the trash....the neighbors kept this mower on the side of their house in the weather and Rain has taken it's toll on it...

lots of corrosion and rusted wire's through out mower....so i'm attempting to go through the wires and get current to the starter...

i bought myself a multi-meter and i'm trying to figure this puppy out....what i've managed so far, is to figure out how to check voltage from battery...and along lines to the solenoid....i've cleaned positive line from battery to solenoid
and have current....12.5 and 12.3 volts reading on meter...

solenoid is new...cause when i tried to clean lines on old one...and loosen nuts on it...it broke apart...

so i can make starter turn buy hot wiring...from battery and from solenoid..

next thing i tried to check was the ignition system...i pulled the plug harness off the key switch...and there is some corrosion inside....sprayed electrical cleaner in it....and tried to gently scrape clean....still no connection through it....connected the volt meter and got a little something to register on volt meter.....but i wasn't sure how to set the meter up......i was thinking it should be set for ohm's and i really don't know how to go about doing that..

if someone could pass me a simple rule of thumb on how to set the meter up...on different areas of the electrical system...it would help me greatly..

at this point i'm thinking sense the starter turned by jumping it.....my problem may be in the harness to the ignition or a safety switch someplace....but i need to figure out where i'm losing the current path and make sure i have this meter set right....

i'm following starting procedure from neighbor....clutch pinned while trying to crank....but still no current to starter....and to top it off the wiring schematic for the ignition system on the internet doesn't jell with whats on the mower....looks like someone changed the key switch and wire harness on this mower before and it's not the factory type on wiring chart.....wiring chart says it should have a 15 amp fuse....and this one has a 30 amp fuse....the plug in on the key switch is totally different...and some of the colors don't seem to jell with schematic....

wow feels like i just wrote a novel.....lol
cajun


----------



## tommyj3 (Sep 16, 2006)

Here'e a good site on using a multi-meter.

http://mechatronics.mech.northwestern.edu/design_ref/tools/multimeter.html


----------



## cajunh2s (Apr 19, 2007)

thanks tommy.....this will be a great help.....i think i have a safety interlock problem somewhere.....this info should help me pin point it

cajun


----------



## pyro_maniac69 (Aug 12, 2007)

one way that you can quickly find out if you have an interlock problem, is take a flathead screw driver and cross the terminals on the solenoid, if the starter starts rooling the motor over, your on the right track.

Have you also figured in that the ignition switch is bad?


----------

