Short or Electrical Discharge

[dond13]

I have a Red 09 4.6 with the Tech package. I got it in February and had to have it towed in a couple of weeks later with a dead battery. They replaced the battery and kept it overnight to check for a discharge and said everything was fine. I picked it up and it has been OK until Sunday morning, 3/29.

I tried to start it then and the starter would turn the motor but not fire. I tried several times and then checked the battery. It registered 8 volts. I charged it up to 11.5 v and it started. I drove it and when I put it away for the night it registered 12.55 volts. Twelve hours later, it showed 11.77 volts, so it has a discharge somewhere. I took it in this morning and got a loaner. They said that they would keep it for a couple of days to check.

I guess my question is, has anyone else had a problem with something causing a discharge that could be related to a function not turning off or anything like that? I know that shorts used to be very difficult to find, but with todays computers in cars it should be easier. Any experience with this??

 

[Nabber]

I wonder if you have a bad battery, but one would think they could easily figure that out. I have converted my 12v outlets to always be hot and charge my cellphone & iPod and haven't had a problem. Good luck!

 

[Mark_888]

I have converted my 12v outlets to always be hot and charge my cellphone & iPod and haven't had a problem.

If you look anything like you avatar, I am not sure I would agree with that.

 

[jonah]

I have converted my 12v outlets to always be hot and charge my cellphone & iPod and haven't had a problem.

always hot?! how did you do that?

 

[Nabber]

If you look anything like you avatar, I am not sure I would agree with that.

LOL

As you can see, I'm perfectly normal!

 

[Nabber]

always hot?! how did you do that?

I've got a few pictures of the modification (really easy) in my album, as well as a thread somewhere in the ether.

 

[Calvin]

Since I got my 4.6 with all the "tech stuff" I thought it would be wise to keep a small trickle charger on the battery. For the first 4 months while the weather was cool the trickle charger would top off the battery in about 30 min. It got kind of warm in April and all of a sudden it started to take over an hour to top off. I got a little concerned as to what it could be when I noticed that when the car sat in the sun for awhile it took longer to charge up. So yesterday after I pulled her into the garage I went over the entire car and found that in the trunk behind the passenger side molding, a fan was running. It was coming from the area of the power amp. I did not have the audio system on but the fan seemed to be running. It finally went off after about 10 min. I am assuming that the power amp must have a thermostat on the fan. I am surprized that the fender area got hot enough to kick on the fan even when the amp was off! I will have to keep an eye on this when it really gets hot this summer. I am planning to check the voltage drop by not using the charger and see how low the voltage might go.

 

[Mark_888]

Since I got my 4.6 with all the "tech stuff" I thought it would be wise to keep a small trickle charger on the battery. For the first 4 months while the weather was cool the trickle charger would top off the battery in about 30 min. It got kind of warm in April and all of a sudden it started to take over an hour to top off. I got a little concerned as to what it could be when I noticed that when the car sat in the sun for awhile it took longer to charge up. So yesterday after I pulled her into the garage I went over the entire car and found that in the trunk behind the passenger side molding, a fan was running. It was coming from the area of the power amp. I did not have the audio system on but the fan seemed to be running. It finally went off after about 10 min. I am assuming that the power amp must have a thermostat on the fan. I am surprized that the fender area got hot enough to kick on the fan even when the amp was off! I will have to keep an eye on this when it really gets hot this summer. I am planning to check the voltage drop by not using the charger and see how low the voltage might go.

That's why I would neve consider a black car in a warm climate (or anything even close to black).

 

[Calvin]

I originally wanted a Pearl White but then I would still be waiting and would not have enjoyed my Genny for the past 5 months! Life is to short to wait! My last 3 cars had been white and they needed to be cleaned all the time (showed all the dirt). The black pearl does a great job of hidding alot of the dirt. I also did my homework about a "black" car being hotter (see address below). My concern was cabin temp. so black did not bother me that much. I did not consider a power amp mounted real close to the outside fender.
Oh well, I did keep the charger off and the voltage stayed well above 12V after the fan ran for about 10 min. So this does not seem to be a big drain on the battery. Next test I will keep the car out all day when its real hot and see if the fan runs all day.

http://tom-morrow-land.com/tests/cartemp/index.htm

 

[dond13]

An update on my electrical problem. When I got my car back from the second service of the problem, they said that they found a missing bumper on the underside of the hood that depresses a contact for the theft alarm system. They had kept it for three days before they found it. Evidently, there is a cycle that checks for this contact and it was detecting that the contact was open. I'm not sure I understand exactly what was happening, but so far, it seems ok.

It failed to start the last time when I hadn't driven the car for 3 days. I haven't let it set for that long since it was 'fixed' so I am not 100 percent positive that the problem no longer exists. I will try it again and let it stay in the garage for 3-4 days and see if it starts.

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[Mark_888]

My concern was cabin temp. so black did not bother me that much. I did not consider a power amp mounted real close to the outside fender.[/url]

I would think that the roof being black would heat up the cabin, and make it harder to keep cool once you were operating the car.

Here is the "Executive Summary" from the link you posted:

"For those who just want to know the results of the test, I'll tell you. The glass temperature (which I assume to be a proxy for interior temperature) varied only 5 to 6 degrees between the black and white cars on average. So I conclude that the interior temperature only varied somewhere in the neighborhood of 5 to 6 degrees. The paint temperature, however, varied by about 55 degrees, which is ten times as much. So it is indeed true that black paint is much hotter than white paint, but the interior of the black car isn't that much warmer than the white car."​

My comments are as follows:

1. He assumed that the glass temperature was a proxy for interior temperature. I don't know how he decided that, but I would seriously doubt the accuracy of that assumption.

2. Even using the glass temperature, he found the interior temperature difference to be in the neighborhood of 5 to 6 degrees. That is not that bad for getting into hot car, but remember you also have keep it cool once you start driving. A cooler car uses less gas to run the AC and is a quieter car, since the auto climate control will turn the fan up higher if needed.

3. The black hood was 64 degree hotter than a white hood. That makes it tougher to keep the engine cool as well.

4. The outside air temperature was approximately 80 degrees F when he conducted the test. I would like to see what would happen when it is about 90 - 100 degrees.