BlackOp

So last night was pretty cold and I went outside to warm it up. It started as it usually does..and I turned on the heater. I went inside for about 10 minutes and came back and it had died. The heater drained my battery..so I couldn't start it. The engine was warm..

What would make it just die while idling...I swapped DME's but the battery was too low to crank. I couldn't get enough momentum to push start it. The DME relay is 6 months old..

I haven't had any issues with it....how long will a car run if the fuel lines are frozen? I haven't tried jumping it yet...and of course I immediately think..did the timing belt just go. I don't want to cause damage..

Fuel pump? reference sensor? Bad DME (main) or relay?

JohnKoaWood

Alternator output at idle not high enough to support the heater running on high...

I would look at the alternator for your issue.. or the wiring running to it!

Hollywood D

If the alternator is out, then you're just running on whatever juice is left in the battery. Gasoline won't freeze unless its super crazy cold out. I believe the freezing point is around -150F

BlackOp

it's residual water in the lines that freezes....haven't had any symptoms of a failing alternator. I hope that's the issue.. I've warmed it up it like this before.

Hollywood D

Ok, I thought you meant the actual gasoline itself.

You can always test to see if you're getting fuel by pulling the cap off of the end rail. You just need enough power in the battery to turn the fuel pump on for that.

Pull the dme relay out and have a look at it. See if the contact points are turning brown or discolored. If they are, replace it.

Do you have a battery tender? Pick one up at the parts store and throw it on there and see if it will hold a charge. Or just take the battery to the store and they can test it. The battery could be kaput too.

JohnKoaWood

"I started the car, let it idle, it died, battery too low to restart"... Maybe I am paraphrasing a bit, but isn't that what your post said?

Battery being too low to start the car? You should have been able to run the heat for 10 minutes without it killing the battery... unless the battery was on its way out, and the heater was on full blast...

NOW if the car was running, but not charging, the heat was on, and you had a semi weak battery to begin with... it still should have kept running... if the alternator was up to snuff...

I bet if you jump start it... it will die again shortly after disconnecting the jumper cables...

BlackOp

Well, actually it was more like 20 minutes..I got a phone call. Yes..the heat was on full..it ran long enough for the motor to be warm. I haven't had any battery/charge related issues prior to this..

I guess I'll give it a jump and see what happens....it just seems odd to have died...it's been running perfectly.

JohnKoaWood

@ idle it probably took 10-15 minutes to warm up (given the outside temps were likely close to freezing there last night)...

which leaves between 5 and 15 minutes for it to kill your battery... I'm almost willing to bet it died because the battery died... and the battery died because it wasn't being charged running at idle.

Jump start it, and watch the charge gauge at idle... turn on the heat to check for yourself...

IF the alternator were charging at idle, it should have kept running till you came back out...

BlackOp

Well it did exactly what you said...ran for about 4 minuted then died.

You had mentioned checking the wiring..what specifically should I be looking for. Is it odd that I drove around two days ago without issue...then parked it and it just failed?

Thanks for the advice...you nailed it.

Cra$h

In the FWIW department, make sure your cables are good. Specifically the ground. I chased a problem with a variety of different symptoms for over a year, that turned out to be a bad main ground. I only mention it because I thought for sure my alternator was bad, but it just couldn't get enough juice through the corroded cable to charge the battery.

JohnKoaWood

Durring the 4 minute run, what was the voltage gauge doing?

The votage regulator can be swapped ON the car... and MIGHT be able to be sourced from a local parts place...

look the cables over for breaks in the insulator on the cable, corrosion on teh cable at each connection / any breaks in the jacket... corrosion at each connection point.

BlackOp

The gauge was resting at the bottom..showing nothing. I have a new voltage regulator around here somewhere..

JohnKoaWood

Find it and put that in first... wont cost anything but the time to put it in!

Check out the cables while you are in there... (blue one is the field sense wire... if it is disconnected the gauge would be jumping all over the place)

The other cable runs from the alternator to the starter... (if it was disconnected it would start, but kill the battery as the alternator output would be zero)

It starts so the battery to starter cable is likely good...

go for the new regulator first, if that doesn't fix it, it is either the alternator itself or the cable... in that order!

ALSO forgot to ask... how does the alternator drive belt look?

BlackOp

Belts are fine... checked them right after the jump. Just to clarify..a faulty voltage regulator and not the actual alternator could produce these symptoms?

carlege

When the regulator fails, the charging system usually ceases to function -- except in cases where the nature of the failure causes the alternator to run wild and overcharge the battery.