My battery light started coming on in September of last year. Eventually car started dying. After replacing alternator, all battery cables, the battery, and even trying a new ECU, and checking the wires from ECU TO ALTERNATOR, the problem turned out to be a a/c blower that was drawing way too many amps, due, apparently to water in the connector. Cleaned the connector, put some grease in, and no light until this week.

Please share your thoughts on what to look for.

Thanks !

 

Anyone has any ideas on this?

Thanks!

 

Measure the battery voltage with engine stopped and running. Is the alternator charging?

Read codes. There are about four different P-codes associated with the charging system. You will need a code reader that reads more than the basic OBD codes. The reader I borrowed at Advance Auto was able to read chassis codes; I'd expect it would read the extended P-codes.

JTIS provides good guidance on these P-codes.

 

This was given to me by Chris "Thermo".


What you will want to do is to go out and sit in the driver's seat. Depress and hold the TRIP button on the end of the turn stalk and then start the car as you are depressing the button. Once the dash flashes that it is in the diagnostic mode (will say "TEST" or "Engineering Test Mode"), release the TRIP button. Now, you can repeatedly press the TRIP button to make the instrument cluster cycle through the options. What you are looking for is the screen to say "DTC XXXX" where XXXX is a 4 digit number/letter combination. If you go one push too far, you can press the "A/B" button down near the headlight switch. Once you write down the first DTC number, press the TRIP button again to see if you have more than one code. If you have more than one, each press of the TRIP button is going to show you another DTC code. Write all of them down. You will know you got to the last one as the screen will then go to "E XXXX" (if you are parked, should be "E 0000" as this is the digital speed using a scale of 0 to 4072).

Now, to decipher the DTC code(s) that you got, you need to first look at the first character. It will be one of the following:
"1" is for P1 codes
"9" is for B1 codes
"A" is for B2 codes
"D" is for U1 codes
"E" is for U2 codes

From there, you take the last 3 numbers and tack them on to the characters you got from the little conversion I just had you do. This will tell you all the DTC codes that your car is experiencing.

This procedure will expose more codes than what will be read by the local auto parts store hand held readers. Just takes a bit of converting to make it something useful... Hope it can help...


Good Luck,
The Dr!

 

Thanks for this suggestion. The only code that came up with this procedure is 9601, which seems to be some instrument cluster ready code.

The engine light is not what is on on my car ,however. It's the charging light. I have already had this problem before and changed all the things I described on the First post.

Thanks !!

 

I have noticed that my brand new + cables seem to get a lot hotter than the new -ve cables (all the cables are new, including the one to the fuse box) the problem seems to be something drawing too much current again or more than it should.

Any help greatly appreciated

 

You didn't answer the fundamental question from my earlier post. What is the battery voltage with the engine running and not? Are there any other symptoms, like the battery discharging, lights dimming, etc?

 

Thanks do much for your help.

Battery voltage is between 13-14.
Dips as I turn on accessories.

I ruled out the blower fan because it's been unplugged for three days, and today the light came on again.

The possitive battery cable is burning hot. Allow me to repeat again that all cables including the one that runs to the relay box, both possitive and negative are new as is the alternator and the battery.

Also, I noticed that after a short drive on a mild day (70's), I got to my parking spot, placed the key on the on possition and the fan just ran. My obd2 reader said the car was 207.

If this keeps up my new battery cable is eventually going to melt or fry. Why would the positive cable be so extremely hot when all these items are new?? Could it be that something is ocadsiknally drawing too much amps?

Please help !

 

Thanks do much for your help.

Battery voltage is between 13-14.
Dips as I turn on accessories.

I ruled out the blower fan because it's been unplugged for three days, and today the light came on again.

The possitive battery cable is burning hot. Allow me to repeat again that all cables including the one that runs to the relay box, both possitive and negative are new as is the alternator and the battery.

Also, I noticed that after a short drive on a mild day (70's), I got to my parking spot, placed the key on the on possition and the fan just ran. My obd2 reader said the car was 207.

If this keeps up my new battery cable is eventually going to melt or fry. Why would the positive cable be so extremely hot when all these items are new?? Could it be that something is ocadsiknally drawing too much amps?

Please help !

 

I should add my mechanic thinks its the cooling radiator fan. He says he once had one pull such a load in an X that it fried his voltmeter.

 

Are both wires going to the battery + terminal equally hot? If so, this indicates that the alternator is likely being overloaded. If not, you could have a bad (high resistance)electrical connection in one of the wires.

Feel each of the fuses in the power distribution box. Any fuse getting particularly hot?

 

[QUOTE=Spikepaga;921197]I should add my mechanic thinks its the cooling radiator fan. He says he once had one pull such a load in an X that it fried his voltmeter.[/QUOT

No big surprise there. The cooling fans are powered via fuse F8 (90A) in the power distribution box. Most multimeters can only measure 20 or 30 amperes.

You could try pulling this fuse to see if this corrects the "hot cable" issue. Just remember, the fans will not run, so keep an eye on the temperature.

 

Just to give an idea of how how the + cable is getting, measured temperature with my infrared thermometer at different points in the cable, including the battery connection and the battery split,, and it was mostly 166-175. As I got closer to the alternator it went up to 200, but I do realize that's in a hotter area as well


In contrast the negative cables where 105-109 f.

I tried to start the car and noticed that the cable seemed to get immediately hot, before the fans ever came on, so I am thinking it's not the fans. ....

I hate electrical problems :-(

 

Well, got some news on this. The cable that runs from the positive terminal to the fuse box is cool along with the negative cables. I guess that means it's not the cooling fan, right? Otherwise the cable from the positive to the fuse box would be hot at both ends too, correct?


Thoughts?

 

Anyone with a similar experience or any ideas? I fear eventually the car will start stalling as it did before.

 

Anyone?

 

You are correct. All loads, other than the starter, are fed from the fuse box. The alternator feeds all of the loads that fan out from the fuse box AND charges current into the battery.

The fact that you said the positive cables between the alternator and starter, and the positive cable between the starter and the battery are both getting hot but the positive cable between the battery terminal and the fuse box is not hot would suggest excessive current is flowing into the battery. But charging current that flows into the battery positive terminal must flow out the negative battery terminal and cables. Because you state that the negative cables are much cooler and the battery voltage, with engine running is in the right ballpark, overcharging doesn't seem likely.

The big unknown here is the actual current flowing in all these cables. If you have access to a DC clamp-on amp meter, try measuring the current in all these wires to determine what is really going on. The other possibility is the cabling between the alternator and battery terminal isn't heavy enough. You stated that these cables are all new. Are they the same gauge as the negative cables?

 

Guys I had the battery tested and it's coming up as bad.

Can a bad battery overheat a possitive battery cable ??

Anyone who knows please reply

Thanks!

 

Well changed the bad battery, light still coming on. The positive cable still getting hot. I did notice that it appears that the heats begins at the crimp between the terminal and the cable, so I took some pliers and tried to tighten it. Still gets very hot. I am out of ideas here.