Red Alert's starting issue...

[sman]

I would start by doing the basic tests I mentioned before. They are basic electrical tests that are starting points that I do on every car that has issues like yours. Right now you don't know if you chasing a electrical draw or bad connection issues so it is a guessing game. If your lost on how to do some of these tests feel free to PM me.

Do this, this will at least let you know what your working with.

[MP81]

Yikes lots of replies since yesterday!

The alternator is painted, not powdercoated, but I'll make sure the mount points are clean and clear of any paint. I vaguely remember them being free of paint, but I'll make sure when I put the alternator back in today to get the car drivable again for FBody's at the Barn.

I really don't think it's the battery or the alternator anymore, I do believe it's either a wiring/ground issue or parasitic draw from inside the dash (car alarm or car PC). Then again it could just be all the damn things I've added that require a bit of juice while the car is off. All the aftermarket gauges require constant draw for it to remember the color to light up with, the wideband requires constant power to retain the calibration settings, radio requires constant draw for station settings, PCM requires constant draw, etc etc.

Yeah - but if it was a draw, then why would it start up later?

[prorac1]

Grounds are funny things. They can be "clean", but still not be getting good flow. Eric L

[MP81]

Grounds are funny things. They can be "clean", but still not be getting good flow. Eric L

True that - I had a battery terminal in my Camaro that actually broke free inside, and sometimes it would connect, sometimes it wouldn't. It was funny though, any time you went to move it around to reconnect, it would set the alarm off, haha.

[meissen]

Yeah I'm not sure, Kyle. Maybe the starter was infact getting heatsoaked those times that we would let it sit and then it'd fire back up? Whatever is going on now, though, definitely isn't that.

[steddy]

Yeah I'm not sure, Kyle. Maybe the starter was infact getting heatsoaked those times that we would let it sit and then it'd fire back up? Whatever is going on now, though, definitely isn't that.

I have a battery load tester (automotive), if you'd like to use it. I use it on the bike battery yearly before startup.

[meissen]

I put the alternator back together, put Dan's Interstate battery in, double checked all the connections to make sure they were good and tight, car fired right up. Detailed under the hood so it will be nice and shiny for tomorrow, closed the hood, got in the car to pull it out of the garage to detail the exterior... (turn the key) *click* ... (turn the key) *click* ... (turn the key) *click* FML I noticed for this first time that the "CHECK GAUGES" light was on and I think the SERVICE ENGINE SOON light was on too but the light is really dim so it's hard to tell if it was on or not. I never noticed this before so I turned the carPC on and opened PCMcomm... Voltage was only reading 11.4v or so. When I'd crank, the voltage drops down to 10.x ... PCMcomm wouldn't let me reset DTC codes which I've done before when I knew I had DTC errors so that leads me to believe that the PCMcomm wasn't seeing any DTC errors.

I'm hoping that Dan's battery just needs a charge so I have the trickle charger on it. I know the check gauges light comes on if it's under a certain voltage and since I don't remember noticing the check gauges light being on before, I'm hoping this is a different problem with the same symptom/results (no start) and that it's just a coincidence. Dan's battery was only hooked up for maybe 15-20 minutes so there's no way something drained it.

I also checked and the switch for my carPC was definitely off. I'm going to go outside again in a few minutes and measure the voltage to the "12v constant" source on the carPC and make sure it goes to 0 when the switch is turned off - that would prove that the carPC is not draining the battery since I had the switch off.

[steddy]

To be honest, with the gadgets, I'm kinda stumped. I'm not sure if the CarPC is your friend or your foe.

[meissen]

OK I went outside, took the trickle charger off and measured the carPC's switch. We THANKFULLY did do the switch correctly and the 12v constant source is what we put the switch inline for. So that means when the switch is off, the carPC is 100% off with no power so that rules out the carPC for draining the battery. That's atleast one thing off the list.

I measured across the battery terminals and I was reading 12.5v so I figured OK let's try starting it. Car fired right up so maybe Dan's battery was just drained a bit since it had been sitting out of the car for about a year now. The volt meter on the gauge cluster was reading just over 13v. I turned the carPC on to see what the PCM was reading because I don't trust the gauge cluster's volt meter 100% due to having removed the needle to put the new gauge face on. The PCMcomm which gets the voltage off of the OBD port said 12.6-12.8v. As the car ran, the voltage went down to 12.5v and the volt meter on the gauge cluster went down a hair too. My dad thinks this is normal for the volts to be low because the alternator is charging the battery - does anyone agree? I thought the volts should be over 13.4v?

[ezcruisn71]

Alternator Charging voltage should be 13.5 Volts and up to 14.4 Voltage at the back of the alternator.

[Robert Lawler]

If I'm correct the battery is what is used to start the car, once the car is running the alternator then takes over and recharges the battery but also runs the elec in the car, not the battery. You should be running about 13.5 or over volt wise when car is running. Hope this helps.

[nascarnate326]

Its got to be a ground. Your battery was probably fine, now this one it does the same thing? Ill bring my jumper cables just in case

[ICEPICK]

i would check all wires at this point, dim light and 12.5 means a loose wire.

[OIF1VET]

i would check all wires at this point, dim light and 12.5 means a loose wire.

My thoughts too..

[BigJeffSS]

I would check the voltage at the back of the Alternator and then check it at the battery positive should darn near the exact same. If there's a have big difference you have a voltage lose somewhere in the wire returning the charge to the battery which is usually the same spot that it feeds the rest of the car. I don't know exactly where it meets the positive cable on our cars but 9 times out of 10 it is at the starter

Added: I just walked into the garge to get a beer decided to look over my car and if I was you I would make sure all the connections at the fuse box where all the positives go in a clean and tight.

If that seems good now turn on your AC, headlights and etc and do the same test. If you voltage measures below 12.5 I'd worry the alternator isn't big enough for your car. I still have a gut feeling you have a ground or positive wire that is lose or doesn't have a good connection somewhere since you have had the alternator checked.

Also alternators are rated in amps not volts so if you have a 100 amp alt and are using 150 amps the alternator will not be able to keep with the accessories and maintain battery charge. Also under drive pullies can cause charging issues by not spinning the alternator fast enough.