I am have a drain on the battery for my 2003 Expy. I have traced it to the Black/Green wire (.08 amp drain) coming out of the top of the CJB. I found it after removing the CJB and started testing all the wires. If I put power to that wire it allows me to turn on the interior lamps from the dial switch and my drain increases to like 5.5 amps. I removed the light switch and all the wires to it and no change in the .08 drain.

Reviewing the wiring diagram on Auto Zones site it appears the wire I found the drain on goes to the instrument cluster and there is a "Interior Lamps Relay" on it that the power runs through to get to the switch. So my questions are:

1. Can anyone tell me if I'm on the right track here?
2. Is the problem likely the Interior Lamps Relay? If so can that relay be replaced or is it part of the cluster and the whole thing needs to be replaced or is it somewhere else?
3. Since the power goes to the cluster could it be something else on the cluster or some other component that gets powered via the cluster?

My CJB looks good inside and out no sign of water damage and since I have the drain with the CJB I've ruled it out. If you have some insight I am all ears and all help is greatly appreciated.

Thank you,
Kenny

 

These might help;


On the other hand, you may have already found your problem.

 

What is the problem? 80ma is not a very large drain. All vehicles have some drain, especially the newer ones. 80ma is on the upper end, but you should not notice it if you drive the vehicle every couple of days. You definitely would not notice it if you drove it everyday.

 

Grubb, already did all of that to get me to where I am now. Pulling the fuses did nothing, pulling the white wire terminal on top of the CJB got ride of the draw all together so I traced down which wire and got the above results.

Franklin, why is everything I've been reading here and on other sites saying anything over 50ma is a problem? That's whats got me concerned and searching.

 

I did some searching several years ago on the subject. I did it, because some people insisted on using a ammeter to test for a drain, while most people commonly use a testlight. But rightly so, who knows how much current it takes to light a testlight, it will depend on the bulb they use inside the testlight.

So I looked around, and it seems as the vehicles have gotten newer and newer, the drains have gotten higher and higher. The best I could come up with back then was 70ma was the most you will probably see. That's why I made the comment I did, since 80ma is still near the ballpark figure I came up with during my research.

I really don't know if anyone would really know the reading you should be getting on your particular vehicle. It would all depend on the accessories and how it's equipped. I do know the drain thing is becoming a problem, because during my research I ran across a bulletin from GM, telling the car dealers not to let the vehicles on the lot sit for over 2 months, or they risk the vehicle not starting because of the normal parasitic drains from the electrical components in the vehicle.

If you do not have a problem with the battery being drained on a regular basis, I would not worry about it. Sorry I can't get you a firmer answer on the amp reading though.

 

I know that more recent household items such as; stereos, tv’s, dvd players, vcr’s, computers, coffee makers, microwaves, and anything of this type have power running through the circuitry even when off. I would ASSume that the newer vehicles are very similar. Along that line of thinking, I would say that stereos, navigation systems, dvd players, clocks, and many other electronic systems in newer vehicles would act along the same lines. Although minimal, the cumulative effect of parasitic drain could add up from one system to the next. I am not saying that you don’t have an issue, but merely that there is a possibility that it could be multiple things adding up to a higher level of drain. I guess what I am saying is that there is a possibility of something in your instrument cluster or in that circuit that may require a certain amount of power at all times. I know in my wife’s Mazda 6 there is a light in the instrument cluster that flashes all the time, and the interior lights will go off after a period of time by themselves, as well as the exterior lights turning off after a period of time. I would think that there would have to be some power to these circuits to properly work when the rest of the vehicle is turned off. Also, remember if you have a key fob and you press the button to unlock the doors do the interior lights come on? Wouldn’t there have to be some small amount of power going to something electronic, such as the interior lamps relay, to keep it on so that it will know when to turn the interior lights on once the doors are unlocked? Just a thought.

 

You can figure out how much drain is too much for your battery or at least tell how long it should take to drain your battery. Find your battery discharge number.... 400 amp-hours, 800 amp-hours or what ever it is and divide the amp-hour# by the drain. That's how long it should take before your battery goes to zero amps.

Example:
800 a-h battery divided by 1/2 amp = 1600 hours

If it's less than this, you need a new battery or refigure how much paradisaic drain you really have.

 

That's pretty much impossible to figure out, since you don't know how much is needed to crank the engine over, and that will vary according to conditions(hot engine, cold engine, etc.)

I am sure the electrical engineer guys at the factory have figured all this out, and you never know, there may be a number listed somewhere in the factory service manual that gives you a good amp number and a bad amp number. You may be able to go by your local dealer and talk to a tech there. My local dealer is really friendly and lets me chat with the techs if I have a question.

 

Well based on the info you all have provided I think I will just wait and see what happens. It sat for about 36 hours and started just fine this morning. So hopefully the battery was the problem. Thanks for everyones help!

 

I just added some more pages of troubleshooting help, and I will be adding more soon. Just in case you need some extra help;
Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.

 

I didn't do this for starting power, just trying to help him figure out if the drain is greater than what he found or if the battery is on it's way out. ie . .... battery drains down in 2 hours with just half amp drain.....

Sounds like a mute point now as it sounds as if he found the problem.....battery.