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Registered
1986
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9 Posts
Discussion Starter #1
I just got a 1986 Fleetwood for free because the previous owner was fed up with the battery draining often.
I dont know the exact details weather it drained while driving or sitting.

I plan on buying a new battery, then start trouble shooting to see if I can find the problem.

any reccomendations on where to start looking?.
I will start with the alternator, what the easiest way to test it?
and if that checks out ok, what should I move to next.

thank you
 

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Super Moderator
2010 DTS
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87,543 Posts
Start by putting a 12v test lamp between the battery cable and the post. If there is a draw, the light will be on. Pull fuses til it goes off. Then at least you know what circuit and or components to look at.
 

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Registered
1986
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9 Posts
Discussion Starter #3
thank you for your reply.
when you say between the battery cable and the post, what exactally does that refer to?
the positive post on the battery and the cable that connects to it??

sorry, i am still learning.
 

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Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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71,004 Posts
Yes - either between the positive or negative post and the respective cable terminal - as in : jumper in the test light. A 12V el cheapo taillight socket, with a single filament bulb, from AutoBone will work. Get a couple of medium alligator clips from Radio Shack, make up the test light, and keep it in your tool kit.
 

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Registered
1986
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9 Posts
Discussion Starter #5
sorry i feel like a total dumbass,
but when you say 'respective cable terminal'
where/what is that.
 

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Super Moderator
2010 DTS
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87,543 Posts
Pull the negative battery cable. Clip the wire on the test light to it. Touch the probe on the test light to the battery terminal. The test light is now "in line" or as Sub put it, "jumpered in".
 

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Registered
95 sedan deville
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113 Posts
also......BEFORE throwing money at something....check over all of your wiring leading from the battery down to starter and over to alt. I found 3 shorts on mines. wires get old and frail from all the engine heat. postive will snake its way down the front to the starter area....prolly passenger side knowing GM products.....the negative will head in a few different directions...and then there will be a pretty thick cable leading to the ALT...prolly a single wore.....follow those along and look for shorts also....GUARANTEED battery drain and i would hate to see you toss money on something not needed yet, then need both sooner or later....prolly most likely sooner
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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6,738 Posts
Just take it to a shop and pay to have it diagnosed. Very difficult to train you on the internet. Or find a mechanic friend and show him/her this thread.
 

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Registered
95 Fleetwood Brougham / 01 DTS / 11 CTS Lux / 11 DTS Platinum
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7,085 Posts
A bad starter can also cause that.

I don't know if this is relevant on the Fleetwood or not but I need to mention this. I'm sure the setup is similar. I had a crazy intermittent draw in my 89. Now that's an STS but for this system I think it could be similar.

My mechanic spend hours and weekends pulling fuses looking for this mystery draw. Finally I took it to the dealer and they found it in 2 hours.

It was what they call the Level Ride Control Head. Now don't be fooled. There is a portion of this when you look at it that is fused, and when you pull the fuse the power goes away. Oh but the battery still goes dead, can't be that, right? WRONG. On mine, there's another wire on top of this thing that you can't really see that ISN'T fused.

The control head would sometimes stick in the open position draining the battery. So if you're chasing your tail and nothing seem to fix the problem, have someone take a look.
 

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Registered
1993 Cadillac deville sedan 1986 cadillac deville RIP
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1,498 Posts
I think its the alternator I got a 86 deville and when I got mine it did the same thing . 3 days I had a dead battery and I didn't drive it just pplugged it in . I changed the alternator and never had the problem again . I agree also with the post above get the altnator tested and check your negitive post on your battery good luck
 
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