Nissan Repair: checking alternator, late model cars, volt ohm meter

Question
this is just a general question,,as I can't find a expert on my car...

It used to be one could remove one of the battery cables, on vehicle when running, and be able to find out if the alternator was putting out...

Now one person tells me I can do this, but seems to me, I read somewhere that you can no longer do this on cars because of all the elctronics...and if you do it you will mess something up electronically....

I am speaking of a 1990 Honda, F/I elec windows, antennae, roof etc...power steering, a/c cruise,straight stick...

Do you have any idea if such a thing would do damage electronically,,,regardless if its a Nissan or a Honda?  or any vehicle for that matter....cause their all electronics these days...I appreciate your thoughts on this...when you have time....put me at the end of your list kid...and thanks.....pj

Answer
Pat, you are correct in not taking the battery cable off when the engine is running as it can blow some of the electronics in the computer and even the newer style alternators.  There are two ways to check the alternator output.  First, you could purchase a volt/ohm meter and check it while the engine is running and off.  Running should put out something like 14.2 volts when you rev the engine to about 1800 to 2000 rpms.  Or, the easy way is to take it to Autozone or Checker and have them check it for free...  Oh, on late model cars like General Motors they suggest taking the fuse to the radio out before jumping the car to keep from frying the memory board in the radio.