Alright guys, I've tried everything. I'm running 17.9v and all grounds are in place, no burnt wires or anything. Any ideas?
Ok, I have been trying to follow everything going on here. Voltage is high on AutoZone tester. dash bulb has been change, no difference, new grounds but idles better.
Can we get a digital multi meter? They are cheap to expensive but accurate. Use DMM at battery to alt. B+ terminal to see actual voltage. Still 19 vdc? OK, Check voltage at battery actual bolt or top post terminal as long as they are clean. 19 volts?
The voltage regulator is fried. Purchase what brand you want but I would use an ACDelco regulator and heat transfer grease from package. No hard to do in your garage.
The battery acts like a capacitor in the electrical system as it calms A/C voltage leakage from rectifier and read about 0.16 vAC at the battery to ground. Rev the engine up and it should not exceed 0.90 volts A/C. Triple this reading if tested t alternator, but still not above 0.90 volts A/C. Even though the battery starts, it should be tested. If bad cell or boiled with a reduced state-of-charge, will cause the alternator to do crazy stuff. I have and use a Midtronix conductance tester. It sends an A/C sine-wave thru the battery and analyzes it, when it returns to the tester.
It has been required a GM dealer since 99 to get warranty on a battery.
"Brown wire" This is turn-on voltage going to dash lamp. The peanut 194 bulb is a current limiting device. Many GM's for decades used a 460 ohm resistor in parallel with this bulb. Bulb is hot with key, voltage goes to regulator, but current is limited. Alternator turns on, produces the same voltage as supplied by the key to bulb, bulb goes out. (No potential for current to flow) Say, 12 volts on bulb, alternator is ground...lights on. Start up, alternator comes on and 12 volts got back to bulb, bulb goes out because on lesser voltage for current to flow, thus bulb is ineffective.
The resistor in parallel with the bulb, is to allow the alternator to continue to work if the bulb fails. Newer alternators with "Delta" wired stators & different regulators work internally for this function. They supply voltage to the rotor at 400 hz, as the older ones supply ground on a "Y" connect stator at 400 hz. The center tap on "Y" connect alternators where hot when working.
I do not have a wiring diagram for your pickups charging system, nor do I know what alternator you have. A self exciting alternator only turns on when rev'd up a little. I have rebuilt alternators since the 70's, but may not be your cup of tea. Fine.
GM's rule is 13.2 vdc when hot and 14.2 max hot...otherwise the battery gets it's butt kicked. So if you have been seeing 19 v, check the batteries current condition, sealed to not.
Voltage is lost across every connection, length of wire, fuse, switch, terminal and ground. So 19 volts at battery, the headlights may only be getting 17.9 volts. This will still shorten their life.
With DMM, set to dc volts, check the alternator B+ to battery terminal, while running for voltage drop. It top post, go with one meter lead on the actual post or side terminal, go to bolt. Just make sure they a clean, tight. Your reading is 0.50 vdc or less. Do the same test with the case to ground, reading should be the same. If high, like 2.3 vdc or more, bad ground from alternator to battery.
Your on a high current circuit as the system current supply split is battery to "What"? The fuse links at the starter, coming from the red battery cable to starter? This feeds the rest of the electrical system thru 3 or 4 fuse links.
Note: Use alternatorman.com to identify your alternator and purchase parts like brushes, regulator, rectifier bridge, brgs., etc.
A fully charged battery at 100% (12.8 vdc) 100% state-of-health, will only take about 0.02 - 0.04 volts to keep it changed, going down the road. The alternator does all of the rest of the work for anything turned on with electricity.
Best of luck. Old dude who hates box stuff & the "Spray & pray" parts in them. (See example of ignition module sold in 2001, 1 is ACDelco, the other is not)
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