I pulled the fuses, now where's the short? 88 lxi

[inwaterby8]

Ok, I'm a total Newb here, and I've searched 3Geez for hours over the last several days trying not to make a duplicate entry, but my 88 lxi coupe is killing me, and my batteries.

I bought this car for $700 a couple of weeks ago. It has a history of not holding a charge - the lady who had it before would charge her battery, then run the car for 5 miles a day to and from work. Everywhere she went, she'd unhook the negative battery cable to park. This would be good for a total of 20 minutes of driving time if her lights were on.

Sounded simple enough, I'd just bolt on a new alternator (which tested bad). I guess you guys are having a chuckle on that one...

1 axel
1 new alternator
1 new battery
1 new valve cover gasket to boot!
Lots of skin off my knuckles
and a whole weekend gone.

and the car is draining an amazing 4.5 Volts on my fancy new MultiMeter.

I've tested all the fuses and switches - with the exception of the main fuse, and a couple of other ones I can't figure out how to remove - you know, the big square ones under the hood... Nothing is draining any unacceptable amounts.

Soooooo, What next? Do I find myself a decent electric mechanic and pay out the nose? I bought a HELM manual, and can understand most of it. I'd like to do the work myself if it's within my realm of ability.

I just need some sort of decision tree. ANY THOUGHTS, LINKS, COMMENTS, OR ADVICE ARE VASTLY APPRECIATED. How do I find the short?

[ShyBoyCA6]

you checked the relays?? relays help the volts to get the right voltage and you check grounds??

im not an expert but it wouldnt hurt to check haha any one wanna add on to this?

[Dr_Snooz]

You have a devil of a problem if you are a newb at this. I'd sooner do anything than have to track down a wiring problem. If by "Helm" manual, you mean the Honda Factory Service Manual that comes from helminc.com, then you have a very good resource in hand already. In the back of that manual will be a series of tri-fold wiring diagrams for the entire car. Use those as your decision tree. At this point, I'd pull all the fuses to see if the car still goes dead. If it doesn't, then the problem is after a fuse. Slowly add them back until you find the circuit that offends and you'll have narrowed the range of possibilities. If the car still goes dead, then the problem is before the fuse box. You can figure out what is where using the wiring diagrams.

Are you experiencing any other electrical symptoms that might point in the direction of the source problem?

Hope that it isn't a short in a loom somewhere, 'cause that will be some fun.

[Accordian88]

have you checked the ground wires?

[inwaterby8]

you checked the relays?? relays help the volts to get the right voltage and you check grounds??

Yes, I pulled the relays - and I mis-spoke earlier. I haven't checked the switches. I checked the relays, which I have a tendency to call "relay switches" - apologies. I am going to pull the rear defrost switch, and the cruise switch, as those two systems don't work.

How in the HECK do I pull those big rectangular fuses like the main fuse without shattering them?

[inwaterby8]

If by "Helm" manual, you mean the Honda Factory Service Manual that comes from helminc.com, then you have a very good resource in hand already. In the back of that manual will be a series of tri-fold wiring diagrams for the entire car. Use those as your decision tree. At this point, I'd pull all the fuses to see if the car still goes dead. If it doesn't, then the problem is after a fuse. Slowly add them back until you find the circuit that offends and you'll have narrowed the range of possibilities. If the car still goes dead, then the problem is before the fuse box. You can figure out what is where using the wiring diagrams.
Hope that it isn't a short in a loom somewhere, 'cause that will be some fun.


Yes, that's the manual I bought.
Yes, I've studied the electric diagrams in the back - and what a picnic that looks like...
Yes, the car still draws when the fuses are out.

I'm not scared to try this, or be patient, or to learn, I just really barely understand how to use my multimeter. From what I gather, I need to hook it back the the battery as I did during the fuse test, and just start pulling apart the wiring harness???

Also:
A friend suggested that the alternator wiring is one of the only parts of the car that could draw that much juice. Any thoughts?
Finally:
what's a loom?

[w261w261]

<< and the car is draining an amazing 4.5 Volts on my fancy new MultiMeter >>.

<< Everywhere she went, she'd unhook the negative battery cable to park. This would be good for a total of 20 minutes of driving time if her lights were on >>.

OK, let's start by agreeing on some terms here. What is "draining 4.5 volts?" Is the car running or turned off, and are you measuring across the battery terminals? Does that measurement show 7.5 volts?

After the PO parked the car with the battery ground unhooked, are you saying that once she started up again, the car would only run for 20 minutes with the lights on before conking out, presumably because the battery was dead?

If you leave the battery fully charged at night, by the next morning is it dead? If the battery is fully charged (12v) when the car is off, when it starts up does the voltage increase to around 13.4v?

If the lights are not on, what happens when you drive the car normally? Do any warning lights come on on the instrument panel? If you start out with a fully charged battery and drive for awhile, what is the voltage at the battery with the car stopped after the drive?

The bad news is these things can be a time-consuming bitch to track down. The good news is it doesn't seem to be intermittent. Unless we can find a quick fix, what you'll end up doing is disabling everything and then put circuits back one at a time, looking for a current draw. Tedious, but it responds to a methodical approach.

[headbanger]

does it have an aftermarket stereo ?If so thats where I would start.

[carotman]

The car cannot drain voltage. Voltage is a difference of electric potential between 2 points.

For example, there is a 12V difference between your negative and positive battery terminal. The car will draw current, which will in the end drain the battery

What you need to do is wire an ammeter in series with the positive battery cable and check how many amperes it's draining.

In order to do this, you need to:

1- Loosen the battery cable but do not remove it yet
2- Put your ammeter on the 10amp scale
3- Connect 1 probe meter on the battery and connect the other probe to the battery cable
4- Remove the battery cable.

You're doing it this way because is you disconnected the battery cable and connected your ammeter directly, the initial current draw could be above 10 amps and fry the meter.

5- Measure how much current draw there is. It it's above .05 amps, there's something draining.

Begin to pull fuses one after another and see which circuit is draining. The bigger fuses need to be unscrewed with a Phillips screwdriver.


P.S. Make sure all door/trunk/lights are off before doing this test :D