Battery Drain (Page 4/7)
deloreanant MAR 08, 12:46 AM

quote
Originally posted by RockinRoger:

Just a silly thought...is the trunk light switch operating properly? If the light does not shut off when you close the trunk, that would cause quite a bit of drain. Just my 2 cents.



I don't actually have a bulb in the trunk light. Would it still cause draw without bulb in there to complete the circuit?
deloreanant MAR 08, 12:51 AM

quote
Originally posted by Neils88:

My dad had a bad drain on his car last year. Since he lives across the country I had to help him diagnose it over the phone and through email. First thing I told him to do was to turn off his headlights. He said his headlights weren't on. I then proceeded to spend several hours back and forth through email trying to help him to diagnose the problem....but was unsuccessful in helping him track it down (no multimeter available). The next day he emailed me back...and admitted the headlights had been left on. Just a reminder to always check the silly stuff first.

Common sources of drains are door/trunk switches, alternators, relays and oil pressure sensor. The best way to find problems is always with a multimeter used to check the current drain in series with one of the battery cables and then start by pulling fuses one at a time to see if the drain goes away. If it does, then you can focus on wires/components on that circuit. A wiring diagram is also a must have item (along with the multimeter).



My headlights certainly are not on, and I don't have stock headlights so it's not a motor running as my headlights are not pop up, but I do see what you're getting at. I guess I should have mentioned that all fuses had been tested by the shops and nothing fuse related is the issue. So I guess relays are next.
deloreanant MAR 08, 12:56 AM
My new fuses for my multimeter came in. Put a new one in and with my multimeter set to 200mA the reading immediately jumped to 63. something then blew that fuse. Good thing I got a five pack. I disconnect the alternator and put in another fuse and the same things happened. I tried using the 10A side but it's giving me trouble too. I think maybe my multimeter hates working properly. I'm not going to promise it's not user error, but I have use multimeters with great success in the past. So maybe I'll borrow one from someone or just buy a new one and try again.
deloreanant MAR 08, 01:00 AM

quote
Originally posted by garage monster:

Just in case others are assuming you know how to use the milliamp portion of your meter and you do not....
Disconnect the positive battery cable from the battery. Put your meter in the milliamp position. Put the positive lead from the meter onto the battery terminal. Touch the other meter lead to the now disconnected cable. Be sure when you do this nothing is turned on including dome lights from having the door open. With nothing going the reading should be near 15 milliamps. There is probably a clock in the radio. If you have an alarm system or remote door locks they will cause a higher reading.

The control that raises and lower the headlights is a common cause of your issue.



Thank you, this was a very thorough reply. That sounds exactly what I've done only I test on the negative side, just in case I manage to drop a lead and it hits a ground on the car as I hold the other lead to the battery. I do not have motorized headlights.

Neils88 MAR 08, 08:02 PM

quote
Originally posted by deloreanant:

My new fuses for my multimeter came in. Put a new one in and with my multimeter set to 200mA the reading immediately jumped to 63. something then blew that fuse. Good thing I got a five pack. I disconnect the alternator and put in another fuse and the same things happened. I tried using the 10A side but it's giving me trouble too. I think maybe my multimeter hates working properly. I'm not going to promise it's not user error, but I have use multimeters with great success in the past. So maybe I'll borrow one from someone or just buy a new one and try again.



Is your multimeter digital or analog? If it is digital and showed 63 before blowing the fuse then the number may be meaningless....they often flash intermediate numbers on their way up to the full amount (unless you mean it sat at 63 for a while, then blew the fuse). Safe bet is always to start at 10A and work your way down. What do you mean by "it's giving you trouble"? If you are blowing fuses at 10A then you have a full short.
spiritwolf359 MAR 08, 09:05 PM
Alright! Let's see if I can shed some light on this subject. Fieros are notorious for bad grounds. This is a good place to start. Go through each grounding station in the car. You can purchase a Fiero book from Autozone and it has a wiring diagram for the car. It will show you each grounding point and the main point as well. Also, an old trick from back in the day was to take a test light and connect it between the positive terminal and the positive side of the cable. The light should come on on the test light. At this point you pull fuses from the fuse panel one at a time. Replace each fuse when you pull them out. Watch the test light and see if it goes out each time you pull a fuse. When the light goes out, you found your drain. That is where your repair begins and hopefully ends the problem. I hope this works for you. It has solved all my power problems in the past.

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JSM

Neils88 MAR 08, 09:24 PM

quote
Originally posted by spiritwolf359:

Alright! Let's see if I can shed some light on this subject. Fieros are notorious for bad grounds. This is a good place to start. Go through each grounding station in the car. You can purchase a Fiero book from Autozone and it has a wiring diagram for the car. It will show you each grounding point and the main point as well. Also, an old trick from back in the day was to take a test light and connect it between the positive terminal and the positive side of the cable. The light should come on on the test light. At this point you pull fuses from the fuse panel one at a time. Replace each fuse when you pull them out. Watch the test light and see if it goes out each time you pull a fuse. When the light goes out, you found your drain. That is where your repair begins and hopefully ends the problem. I hope this works for you. It has solved all my power problems in the past.




Bad grounds shouldn't cause a drain (but you are correct that Fieros seem to be prone for them and it never hurts to clean and tighten the connections). The problem with using a test light is that small drains may not cause the light to come on. A multimeter gives much more detailed information about the drain.
theogre MAR 08, 11:14 PM
Get AC/DC amp clamp meter and be done guessing how to use DVM, taking apart harness or worse, cutting and splicing it.

you find "cheap" ones ~$50+

Note: Most used or cheaper units, the clamp is AC only but other functions AC/DC. Check this before buying.

Walmart's EverStart made by Johnson Controls. JC makes Many batteries sold thru Kmart/Sears, Interstate, etc.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 03-08-2016).]

LornesGT MAR 09, 12:33 AM
Unfortunately the fuse box is not in an optimum postion to test each circuit but here is an option to buying the meter. Look at the car fuse closely you will see,there are little metal contact point on them, at least many of them. Place your meter on DC millivolts and measure across the fuse on these contact points. If there isn't any current flow the meter will read zero.
RockinRoger MAR 09, 02:29 PM
Without a bulb, there would be no drain.

quote
Originally posted by deloreanant:


I don't actually have a bulb in the trunk light. Would it still cause draw without bulb in there to complete the circuit?