Hoping one of the grey hair super-knowledge folks are logged in right now. Stuck beside freeway with misbehaving car.

Driving back from LA to SF from Sevenstock. Noticed my battery gauge which normally sits on 12v was reading 13v. Then over an hour or so dropped down to 9v. (With a short return to 11v for a few seconds). Then my gauges started to read low, 2900 rpm where I usually see 3300rpm, temp just above C when it usually sits at 1/3, oil at 30pis when it’s usually at 60psi. Then…. Turn signals stop working! At that point I pull over and am now trouble shooting. Belts and battery connections are tight.

Bad alternator with resulting low battery? Would that match symptoms!

 

Update. Tried to restart. No turn. Thinking batter dead but don’t have multimeter with me. Open door warning sounds kinda feeble and headlights flipping up slowly so battery seems likely.

 

I wouldn't discount the alternator being the issue, did you run your visual aid off your battery at Sevenstock? If you drove for an hour before issues started it sounds to me like the alternator wasn't charging the battery as you were driving home and it drained the battery completely.
Just a thought.

 

Alternator require 12v to generate the field around the rotor or they won't charge at all. Your Alternator may be bad, but your battery is DEFINITELY bad.

Replace your battery, then go from there.

 

Yup. Alternator is my theory. Wanted to check that bad alternator then low battery would match the symptoms on the gauges. Going to see if I can find a battery within walking distance, then try to drive so I am within my 100 mile AAA range. Currently at 127miles out, with AAA quoting $15 per extra mile!

 

Battery or alternator would be my guesses. Did only the BATTERY or all warning lights come on? If the alternator was starting to go, usually just BATTERY would light up but you may have had a sudden failure.

 

That’s what I don’t understand. No warning lights of any kind. Just all the gauges reading low, except for mpg which stayed accurate. I just tried a start after 15 mins of sitting and got a half turn before dead. So defn dead battery, and alternator as the suspected cause.

 

Can you have AAA tow you to a parts store? You could have you alternator tested and get a battery. One other thing to consider is your voltage regulator, it regulates the charging voltage your alternator produces keeping it between 13.5 to 14.5 volt range. I hope you will be able to find the cause, and get yourself and you 7 home safely, good luck!

 

this sucks.
if you find a place to get a battery, ask them if they have an alternator in stock. when you get the car started, the simplest test is remove the negative cable while the engine is running. if it stalls out, then you need an alternator.

if they have one, you can just go back to them and pick up the alternator. i'm only saying this because i'm not sure about driving 127 miles without an alternator is wise. i guess, likewise, you still get it towed home once you're within your 100 miles.

hope you get straightened out either way. good luck, Brother.

 

Home!

No one had an alternator within Uber distance, so directed the Uber to the nearest OReillys and picked up a battery. Had the same idea… at least a new battery would get me inside the 100 mile AAA radius. 24 mile Uber round trip later, and new battery is procured and installed.

And….

Starts right up. All gauges back to where they normally are. Decided to try for home. Wanted to eke out every mile so anything that pulled power was turned off, just in case alternator was the issue and I was running on stored charge only. But need not have worried. 130 miles and 2 hours later voltage needle stayed right on 12v the whole time and am home just fine.

And gotta say RX7 folks are the best. Last night I am parked outside the hotel putting expoxy around my coolant level sensor leak and a FD guy pulls up and checks I am OK and offers to loan or get anything I need. Then today as I am installing new battery a truck pulls up…. Driver has an FB and offers the same help. Good people.

 

Glad you made it home.

Do you know how old the battery was?

 

glad you were able to make it home.

i must say ... now i'm curious as what the upper limits of a full charge are in terms of mileage.

 

Battery just over two years old. Had a hard life though… had flooding/stalling problems for many weeks so has had more than its fair share of repeated cranking.

And thanks for the pulling the cable tip to determine if alternator working. Gonna file that away for future use.

And gotta say that engine gave it all. Was still running even when the battery was so low I didn’t have turn signals!

 

Glad you made it home! Back in the early 80s, I and my other stupid college friends drove across Ohio into Indiana with a rental car with an alternator that died somewhere in New York. We would stop at service areas to get the battery charged and then drive another hour or so. Generally the service guys would just do it for free. 10 miles out from our destination dusk had turned to dark, we'd turn on the headlights and the engine would bog, so we just left the parking lights on. We drew the attention of the state police who ended our naive effort to just get home to South Bend. If only daylight had held.

 

At least for one drive the battery voltage gauge deserved it’s prime location on the dash.

 

The recent cold has done weak batteries in . Mine was showing symptoms of failure and my friends outright died on him ( He owns a Passat) .

Mine was flat on two separate occasions so I had to go buy a new one . Always carry jumper cables my friend, they have saved me twice!

 

Yup. Always have jumpers and a bag of tools, including roll of duct tape and some giant zip
ties. Have added a flashlight and a multimeter since the last trip.

Charged battery and tested today. Freshly charged battery reading 12.7v on multimeter. Started car and revved to 2000rpm and voltage dropped to 12.3v. Pulled negative lead on battery and car died. You guys concur this is a dead alternator.

Kinda shocked the car got me home 130 miles with no alternator!

 

1. Get a multimeter.
2. Set your multimeter to DCV (DC Volts) above 15.
3. Make sure your alternator’s positive and negative terminals are clean.
4. Put the multimeter’s black cable to the negative terminal and the red cable to the positive terminal.
5. Look for an ideal alternator reading of around 12.6.
6. Start the car, and look for a reading of between 14.2 and 14.7.
7. A reading of over 14.7 means the battery is being overcharged, while a reading under 14.2 means the alternator is undercharging the battery.
8. Turn the lights, radio, fog lights, fan, and other electronics on, making sure the voltage reading doesn’t go below 13.
9. When you shut off the car, make sure the reading is above 12.6.
10. If any of these readings are off, you likely have an issue with your alternator

 

Found an S4 alternator on EBay. Ordered and on the way.