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Discussion Starter #1
I was wondering if anyone had any advice on tracing electrical problems. I have a service manual(not a haynes, but the real shop version) and a multimeter. I don't see why i can figure out on my own what the issues are with my car.

Electrical problems:

*Something is putting a serious draw on the battery when the car off. How can I find what is pulling power? I have an alarm, but my brand new battery keeps dying whenever i'm working on it and don't drive it for a couple of days. I'm thinking the alt is recharging the battery enough to let it startr within 24 hours. but keep it sitting longer than that and the alarm or whatever else is pulling power drains it down.

*I hear that tiny little fan behind the dodge emblem on the passenger side dash pulling air even when the car is off. I believe this is the climate control's temp sensor, but why is it spinning when the car is off? Normal? If not, anyone had and fixed this problem before?

*Power locks aren't working too well. Some times they work some times they dont. But they always sound like they're struggling to engage and disengage. Slow and labored. I'm thinking a relay has gone bad or a wire somewhere is freyed. but looking for advice on how to fix this?

Thanks,
Mike
 

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Only thing to do is to isolate circuits until you get the right one. If your meter can do 'amps',(10 amps or less is enough) configure the probes accordingly. With the ignition off, remove a fuse, measure across it and see if there is any current flow. If not, go to the next one,until you find battery juice being used. Check both fuse locations. If you don't find anything (unlikely,I'd think,since everything is fused), remove relays one at a time and check for
current flow across the COIL terminals ONLY! You shouldn't find any...
Maybe a relay is mechanically stuck in the 'energized' position, resulting in something being on, but it should stop when the relay is removed...
Keep us updated...
 

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i would first look at the alarm you have installed in there. a poorly installed alarm can have lots of bad effects on your car. find the fuse to it under the hood, or under the dash. that might be draining the battery. if it has remote start system also, that might be interfering with your climate controls. and if you have locks on your alarm, that might be the problem with them too. i always look for the non factory items first when trouble shooting electrical probems. these may or may not be what is causing the problems, but its a good starting point. if you find thatyou need to remove the whole alarm system and start over if that is the culprit. but hopefully it is something else all together thats eaiser. just my 2 cents
 

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Discussion Starter #4
alarkyokie said:
Only thing to do is to isolate circuits until you get the right one. If your meter can do 'amps',(10 amps or less is enough) configure the probes accordingly. With the ignition off, remove a fuse, measure across it and see if there is any current flow. If not, go to the next one,until you find battery juice being used. Check both fuse locations. If you don't find anything (unlikely,I'd think,since everything is fused), remove relays one at a time and check for
current flow across the COIL terminals ONLY! You shouldn't find any...
Maybe a relay is mechanically stuck in the 'energized' position, resulting in something being on, but it should stop when the relay is removed...
Keep us updated...
Which ports on the relay should I hook up to?

I took electronics class in high school, but that was a looooong time ago. So some of the stuff the diagrams the shop manual throws at me is quite foreign. I know it wouldn't take much to get me back up to speed. But I don't quite grasp how to translate the diagrams in the book to wires and modules in the car.

I am going to try and remove the alarm temporarily just to take it out of the equation. then when i get some of the more major problems the car has fixed, I'll take it back and get the alarm guy to fix the alarm to function properly. I'm worried that I'll take power away from my alarm and the starter will no longer fire up. :(

Mike
 

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It is normal for the temp. sensor motor to run for a while whenever you open the door. What is the voltage across the battery terminals when the engine is running.? It should be over 14 VDC. With the engine off it should be 12.6 VDC or a little more.

You can always disconnect the + connector from the battery and measure the current when everything is off. Remove the under hood light if your car has one. The only drain should be from the alarm system and the various computers and radio. I don't have any idea what the value would be but it should be in the milivolt area.

Alarkyokie and cthall8143 are right on the money. If the charging voltage is ok then start isolating curcuits by pulling fuses and watching the ammeter. I too would start with the alarm system. Be patient, electrical problems with a car can drive you nuts. Just my $0.02.

FredB
 

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If you don't have a multi meter you can make the current tests with a 12v lamp. Remove either battery lead and connect the lamp between the lead and post. If it lights there's current being drawn. Now unplug fuses and relays one at a time untill the lamp goes out.
 

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If you pull off the negative terminal and check your current draw you shouldn't be pulling more than an amp or so - but I would expect much less (~100mA). Anything more than one amp and you've got a problem somewhere ...
 

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The very first thing to do is to vedryify that your battery is good, before you try to fix any other problems.
You need to do a hydrometer test to ensure that all cells are reasonably even for specific gravity after being charged (with an outside charger) for 10-12 hours. If any cell is either lower than the rest or has a somewhat greyish appearing electrolite, then it is sulphated and the battery needs replacing.
Next thing is to load test it, which is difficult at home, but can be done. Disable the ignition so the car won't start; then put the multimeter across the battery terminals; crank the engine for 30-40 seconds. The voltage drop from static should be no more than 3-4 volts, then should go back to the normal 13ish volts. You should repeat this twice more to ensure the battery has sufficient reserve cranking capacity.
The final test - high amp draw - you can't do without a proper tool at home, but if the other two are good, then the amp test "should" be OK.
If either one of the above fails, then you need a new battery before you go ahead with any of the checks the other guys have suggested.
 

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Discussion Starter #9
The battery is brand new. I doubt it's the problem. I actually bought one about a month ago while doing a bunch of work to the car. Before i even got to drive on the car, that battery died. So I took it back to NAPA and asked for a new one. They gave me a new one and now that one has died. One lemon I could believe, but two, that's just not gonna happen. The problem is in the electrical system somewhere.

It very well could be the alarm.

Also it's good to know that that fan only runs when the door is open. I was thinking it was running the whole time.

Mike
 

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Discussion Starter #10
How do i go about tracing the problems with my power locks? They act all kinds of funky! Perhaps they too are conflicting with the alarm system. But is there a way from me to trace where the problem lies?

Mike
 

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Hi Mike, well, since you don't need a battery, the the advice about removing the ground and inserting the multimeter on its amp setting is your next step.
Then just start removing fuses and watch the meter. Obviously you'd start with the alarm system :).
 

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>that fan only runs when the door is open...

Actually it starts when the door is opened and continues while the engine is running to monitor cabin temperature. Otherwise it will stop after 30-60 seconds. But it's so tiny that it wouldn't affect the battery for weeks anyway.
One other possibility is the alternator. If you have to, put a charger on the battery to get it to at least 12-13 volts, then start it. Test the battery voltage, it should be 14 volts ±½ a volt. If it's less and slowly dropping, the alternator isn't charging.
 
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