more electrical problems

[redneckaggie]

I have noticed truck seemed a little dead in the mornings when I went to start it(rolling over a little slower and lights are a little dim. I went to have my batteries tested at oreillys and I only disconnected one ground wire and one of them tested bad when on the truck. so i went to get a battery and after buying that battery I had carquest test the one that oreillys said was bad for laughs. It tested good on their tester(in house) so I hooked it up as a third battery. On the way home from work yesterday My battery light came on but the gauge was still saying I have charge. when the batteries were tested I know the voltage on all of them was almost 14 volts so Im thinking voltage regulator.

can I just use my multi meter to test the voltage off the hot post off of the alternator to check the voltage regulator?

I also used silicone spray when re doing the batteries and it got on the blades for the voltage regulator so i dont know if that would mess things up?

 

[Silver Burner]

When the rig is off, the batteries should come up around 12.0-12.6V. When the rig is running, the alternator should be pushing out over 13V up to around 14.5V. Don't know about the silicone spray messing things up. It kinda sounds like the alt. is taking a dive.

 

[redneckaggie]

well the batteries load tested to almost 14 volts with the truck off. do you have any idea of a way to test the voltage regulator?

 

[Silver Burner]

To test the VR, you need to have the rig running and hook up your multimeter to the battery, doesn't matter which. With the rig running at idle without ever having revved it up it should be in the 13V range. Now slowly run it up to 1000 or so and it should increase with engine speed until it catches and locks at a particular voltage which should not be above the 14.5V or so. Then start loading it up one thing at a time. Turn on the lights, turn on the fan, and watch the voltage. It should briefly drop and try to return to its locked voltage. If it keeps dropping as you add load and goes down into the 12V range, that would indicate a bad VR

 

[redneckaggie]

thanks

 

[88beast]

fyi if you run it shut it off and test youll get 14.5 thats alt output
if you turn headlights on a min then test youll get 12.6
the lights will put a draw on the system and that will bring the batts down to their real charged capicity

also check a case ground to see waht the actual voltage is of the batt some voltage is lost through a case ground in bad batts but it will still show 12.6v

 

[redneckaggie]

checked it all out today and the plug for the vr is slipping off of the alt. went to oreillys to warranty the vr after I checked it with the multimeter and when i went to pull it I noticed the plug sure did seem to be sittin weird so i moved it and it wasnt all the way plugged in.... made me feel like a *******. apparently the little clip broke off the connector and its vibrating its way off of there so I ordered a new connector

 

[Silver Burner]

Nice! At least it was an easy fix man! Not a ******* thing at all!

 

[typ4]

Voltage not keeping up under load is also a bad diode/ rectifier sign.

 

[redneckaggie]

ok got everything all settled, new plug is in and alternator is working flawlessly. while I was at it I figured why not perform some overkill so I installed a third battery. I now have two on the passenger side and one in the drivers battery tray. I also ran all new 4 ga grounds from
battery-frame
battery-cab
cab-frame
cab-engine
frame-engine
all battery connections as well as the new ones added where taken apart, cleaned and greased so now I better not have any more electrical problems in my future