'03 minivan: electrical flickering

QuestionEdit

QUESTION: Hi A few days ago I could hear whining from under my car. This morning the battery light came on and then the engine died. Then it started again and I was able to get it home. I have between 12 and 14 volts across the battery and nothing out of the alternator. I changed the alternator as I thought this was at fault. Now when the battery is connected to the car I hear a relay constantly clicking and the instrument panel goes haywire. Could this be something as simple as a ground? If so where do I check all the grounds ? I found the one under the battery and the one strapped to the engine. Thanks

ANSWER: Hi Leigh, Without knowing the year/make/model/body style I can't suggest other ground wires that the two that you found and those may be the only two. Can you start engine and check for the voltage output across the battery terminal? I would wonder if the battery is at too low a charge level to maintain the voltage on the relay that is clicking. Can you identify which relay it is? And what is the voltage on the battery? It is possible that you have a short circuit on the + side of the battery rather than a weak ground connection. But first, try to charge tha battery, start the engine and see if the alternator will now put out 14 volts. If not then we have to find out where the short circuit is that is dragging doen the voltage. Please 'rate' my answer (see below). Thanks, Roland

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QUESTION: Hi Roland

The car is a 2003 Dodge Caravan 3.3L V6. I jumped the battery off my truck and got it started. The battery shows between 14.90 and 15.05 across the terminals. The alternator shows around the same numbers. When I turn on the lights and heater, there is a drop in voltage down to about 14.30-14.50 and it then picks back up slowly to around 14.60. As soon as I switch off the engine, and try to restart the car, that's when the relay starts clicking. It's the accessory relay. It clicks as soon as the key is placed in the ignition and turned. The battery terminlas are extremely clean as are the connectors. The wire connecting to the alternator post is showing some corrosion so I've cleaned that with some emery cloth and contact cleaner. Once I'd replaced the alternator this morning, the car fired up no problem and seemed to be doing it's thing well. I came inside to clean up and as I walked out of the house the car stopped running.

ANSWER: Hi Leigh, It sounds to me that your battery is low on charge perhaps due to the alternator having failed earlier. The output now seems fine, but perhaps your battery just needs to be charged by either driving it or putting it on a charger. You could check the ignition off draw by using the ammeter function of your meter if you have that. Put the meter in series with the disconnected -post clamp and -post. With everything off it might read a few hundred mA to start but it should drop in a half hour or so to 50 mA or so. If not then you would want to start removing fuses one at a time to see which fuse is responsible for unusual draw off the battery. Let me know what you find.

Thanks for the rating. If you would do that again and this time consider a 'nomination' as well that would be most appreciated. Roland

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QUESTION: Hi Roland

I took the car out for about an hour last night and the charge seemed to be working. I then went and bought a trickle charger and charged the battery overnight. I'm now getting a steady reading of 12.67 across the battery posts but I still have the same issues. The car starts from a boost from my truck and runs no problem, but when you start driving it, all the electrical goes crazy. The gauges are very erratic, the lights flicker inside and out, the clock goes on and off etc. Do you think that this problem could be in any way related to the two links below?

http://www.allexperts.com/user.cgi?m=6&catID=807&expID=63082&qID=5015062

http://www.allexperts.com/user.cgi?m=11&catID=807&expID=63082&qID=5014699

AnswerEdit

Hi Leigh, No, I don't believe the problem is related to the earlier ones. I suggest that you take a look at the clamp on the + post of the battery where you will find three wires, and specifically examine the very thin orange wire which may be corroded and making a poor connection. It feeds fuse 24 which then feeds the instrument cluster and body control module. That wire has been shown to be easily damaged by corrosion due to its thin conductor. Roland PS Thanks for the ratings. If you would consider giving me a nomination to be 'volunteer of the month' at the same time on this answer that would be appreciated.