Testing the charging system

[Dino]

Well it looks like the electrical is all up to snuff, except the one bulb in the gear selector but that's not exactly life threatening.

I think the alternator works fine but how can I be positive?  I drove it for about 45 minutes this morning and battery voltage went from 12.50 sitting in the garage to around 12.65.  I think this is normal but I'm not sure.  At idle everything works great though, no more chattering wipers.  The dash lights also are always fully illuminated and don't dim at idle.  Sounds like the alt is working right?

[moparguy01]

Got a voltmeter? check the voltage with the car off. should be around 12, give or take. Then start the car, kick it up to around 2k to make sure everything is going. then check it again. it should be around 13.7 -14? something like that.

[Dino]

Got a voltmeter? check the voltage with the car off. should be around 12, give or take. Then start the car, kick it up to around 2k to make sure everything is going. then check it again. it should be around 13.7 -14? something like that.

Cool, I'll try that.  Is that higher reading the surface charge? 

[Just 6T9 CHGR]

12.5 while running?  Thats too low. Minumum should be 13.2-13.5 IMHO

[Dino]

No not while running, just sitting in the garage, engine off.  I had measured it in the morning and later in the day after I took it for a short ride and got 12.5 and 12.65 respectively.  I have no numbers for the battery while running yet.  I was working on the car today but forgot to measure the battery, will try again tomorrow.

[1974dodgecharger]

That's good as long as your not dropping.  My battery used to sit at 12.5 then drop to 12.2 or so and then eventually down to 12 and under longer it sat. 


When I got a new battery voltage was 12.70 off Batt. off shelf.....now with upgrade alt. that's where my voltage sits at even after a week  of sitting.

[Just 6T9 CHGR]

No not while running, just sitting in the garage, engine off.  I had measured it in the morning and later in the day after I took it for a short ride and got 12.5 and 12.65 respectively.  I have no numbers for the battery while running yet.  I was working on the car today but forgot to measure the battery, will try again tomorrow.

Whats that nicey nice dash voltage gauge say?

[Dino]

I didn't have a chance to play with the car today.  I think all is fine seeing the battery was slightly more charged after driving than before.

The volt gauge is unfortunately unreliable.  I must've damaged it along the way so I need to buy another.  The reading changes every time you turn the ignition off and back on although once driving it seems to be steady.  The decal I made is a little too small, something I'll fix when the cluster comes back out to install the tach, but even with the scale a bit off, the reading seems to be around 13+ when driving.

I may not have the time to look at it again until Monday.  I have a GRE on Sunday and probably should study a bit.   

[b5blue]

  A darn good seat of the pants test is to run it a bit till everything is stable then while at idle turn everything on. Blower on high wipers high lights all on everything even dome light and foot on the brake, blinker/flasher radio. Everything sill running nice? Now turn off blower, did the wipers speed up? If okay turn blower back on, did the wipers slow down? Next try the reverse with the wipers and blower's speed. Try all this at night in the dark and see if the lights dim also.
  You'll need someone misting the windshield for the wipers to be fair gauging performance. My car past this test after swapping to the Denso120 alt and I was so happy I could have cried! You can allow a 1 or 2 second reaction delay as the charging system reacts to the change in demand. To be thorough try with the headlights on high beam also. If all is good your out of the woods.   

[Dino]

Sweet!  Will give it as shot.