car probs

[barryw33]

hi all, was wondering if anyone could give me some advice on how to test my alternator on my car with a multimeter(I know not an @ problem but i am sure theres a few people on here who know how to use a multimeter) anyway got a multimeter from maplin and want to check the alternator direct as its a mercedes and battery in the boot, so could be a cable problem. I have read on a few forums about setting the multimeter to 20 v dc and then connecting the red connector to the alternator and black to an earth. if this is right can someone tell me which is DC on my mulitmeter. one red socket says 10ADC and the other says V upsidedown horseshoe mA

anyway heres a pic of my multimeter



also is 20v dc the 20 on the left hand side of the dial. any help would be great as every autoelectrician i ring is too busy

thanks in advance.

[Roy]

stick it on volts and put it across the terminals of the Batt (make sure it is volts DC 20V if you have such a scale) while the engine is running, if the alternator is ok you will see more than 12V (about 13 to 14 is normal as long as not to much stuff is charging so wait a couple of minutes after you have started it). if less than 12V you have a problem.....

to check the AMPS is a bit more involved.


Roy

[barryw33]

cheers roy, can you look at the image of the multimeter i have and tell me which setting is which, thanks again

[Mad Mav]

Sinner! A car question on a motorcycle forum!!! Repent or get banned!

[barryw33]

sorry but up the stink at the mo as missus is 8 months pregnant and cant take her to hospital on the @

[Mad Mav]

Preggers?....Maybe this time we should let you off then. Just the once mind you.

[Roy]

yes it has 20V scale will do you fine..... give it a go and remember it will be a bit better if the engine is warm.


Roy

[barryw33]

which red socket do i attach the red lead to?

[Roy]

the one next to the black, the other is for AMPS....


Roy

[barryw33]

top man, thanks roy