Car Repair & Diagnostics : How to Test a Car’s Alternator
Posted by admin on October 25, 2009
When testing an alternator on a car, it’s important to first check to see if a battery has enough voltage. Use a test light on a car’s alternator with help from an auto mechanic in this free video on car repair and diagnostics.
Expert: Tom Brintzenhofe
Bio: Tom Brintzenhofe has been a mechanic for more than 17 years.
Filmmaker: Reel Media LLC
Duration : 0:1:39
Posted under auto mechanic
There has been no …
There has been no mention of the exciter feed from the dash light i.e. a blown bulb/ interrupted power supply . Or voltage drop test between the neg battery terminal and the alternator chassis.
Some diesel engines use one of the alternator terminals for the engine rev counter .
This can be a factor to be aware of .
A retard with an …
A retard with an ASE badge on my shirt then. lol I’m not trying to be rude but if you want others to do the right procedures I would recomend you to know the facts. Back in the days you could do that I admit but now it’s all about electrical parts. The deadline for an ASE test is on Sept 30th. I have to redue mine on EP.
The battery acts as …
The battery acts as a buffer and stabilizes any voltage spikes that may cause damage to the vehicles electronics so disconnecting the batt is not a good choice. Do a voltage output and curren output test, a voltage drop test, a full field test if the output test fails. Make sure the batt is fully charged.
do you think any …
do you think any mechanic has an ASE patch on EVERY SINGLE PIECE OF CLOTHING they wear? no. your retarded
JeRkOfF
JeRkOfF
An Alternator will …
An Alternator will not motorize and spin with voltage applied to it, only DC generators do that. A car might continue to run with the battery disconnected but if anything upsets the electrical balance, like turning on the headlights, it will shut off, the alternator needs a small amount of battery power to excite and magnetize the windings or it can’t do a thing whereas a generator uses residual magnetism to generate power.
This guy speaks the …
This guy speaks the truth whether you believe it or not. When connecting your DVOM from the battery to the Alt. it doesn’t matter which one is connected where color test lead wise so long its from the batter Neg. terminal to the Alt. Hot lead ( not the connector ). You should get 13.5-14.8V (DCV) anything under or over that the Alt. is defective.
i’m automotive …
i’m automotive wireman..i special list repair truck ,forklift,car,excavators..eletrical system….
u work like shit~~~
If I don’t see a …
If I don’t see a patch that says ASE on his shirt that means it’s BS. lol I wouldn’t recommend performing this procedure if you’re not an expert. He did the volts but I’m wondering what “is here”? An alt… has volts and amps. Don’t play with amps if you don’t know any about current. Gamzmasta I wouldn’t recommend your procedure either. Never, never disconnect a battery while it’s running.
gamzmasta, you …
gamzmasta, you almost got me with this one… lol
GOT NAP?
GOT NAP?
theyres a easier …
theyres a easier way, its my way!, lol.
on a serious note, just disconnect the battery terminals while the car is running, if it turns off the alternator maybe dead, if it still runs your ok, check fuses and wires before buying a new 1, final test when you have taken it out the car, conect it direct to a battery and it will spin like a fan if it is working be carefull when trying this, e.g make sure you use jump leads or something, and that you wont injure ur self
He kind of ” …
He kind of “shotguns” the alternator. he didnt check for amp output, good effort though, I hope all the fuses were checked before alt. replacement……
so do u touch …
so do u touch negative battery terminal and alternator terminal for the reading?
this guy is drunk …
this guy is drunk or what