.25 amp parasitic draw through dome fuse

[mstgeer]

Car has been in rebuild mode for the past 2 years and I have been able to get it back on the road in the last month or so.

I had actually forgot about this sitaution. Went to start the car on Saturday and it was dead. Put the charger on 2amp charge overnight and still dead. This is the 3rd battery the car has killed in the last 5-6 years.

So after some google and supramania research, got the multimeter out, wires in series to the battery and read .25amp draw. Started pulling and replacing fuses, one at a time. Get to the dome fuse, pull and the draw drops significantly (don't recall exact drop).

Is there any common history of a part failure that causes this draw? I do notice that the interior lights tend to dim in steps vs. a smooth gradual fade and my aftermatket radio (sony) will not pick up any radio stations, all I get is static, the power antenna mast still extends and retracts as it should. Both of these circuits as well as others are powered through the dome fuse.

I have the '91 ewd and tsrm for reference, but just trying to see if anyone else has had to fix a situation like this and what was the faulty part?

 

[stew_7mgte]

If you can get a wiring diagram of the dome light circuit you can find your short really easy. You said the dome light still works though? Find out what else is connected to that fuse.

 

[Maple191]

It means your dome is getting power where it should not be getting it from. Its back feeding off another circuit, somewhere along the wiring.

 

[stew_7mgte]

From my experience with electrical problems is if that particular component is operating as it should be then the fault is not there. I looked at the tsrm and there are several other components on that dome circuit. There is a short to ground somewhere there you just have to find it doing a series of voltage drop tests.

 

[mstgeer]

Dome fuse powers:
All interior lights, long list
ECT ECU not app. to 5 speed
Integration relay #1
Theft Deterrent ECU
Clock
Auto antenna motor
Stereo component amp
Heater control assembly.

What I am struggling with a little is how to isolate and disconnect each circuit, one at a time to see which one has the draw.

 

[stew_7mgte]

If your stereo worked at one time and then suddenly you got static one day i would check the wiring there. You may have a short to that wire causing interference on the radio. Only other option i can think of is pulling each component out and doing a voltage drop across each one. Its tedious but with obd1 you dont have many options.

 

[Dan_Gyoba]

Do you have an aftermarket deck? I recall that it also powers the constant power for the deck. Many aftermarket decks also use constant power for other functions. My Pioneer used to draw over 120mA just from some the transistors used to turn on the power antenna and amplifiers.

Also check the light fixture in the hatch. I've accidentally turned that on and left it that way before.

 

[mstgeer]

Do you have an aftermarket deck? I recall that it also powers the constant power for the deck. Many aftermarket decks also use constant power for other functions. My Pioneer used to draw over 120mA just from some the transistors used to turn on the power antenna and amplifiers.

Also check the light fixture in the hatch. I've accidentally turned that on and left it that way before.

I in fact do have an aftermarket Sony deck. The plan is to pull that tonight to see if the draw is reduced. I am a little confused, as my '91 does not nor appear to ever had the amp under the seat. I thought all '91's came with it??


I eliminated the power antenna as the culprit last night, no change when removing the relay in the hatch area. I have in my mind that it is going to be the integration relay that is the issue, based upon some internet research and the fact the dimming of the interior light is not smooth and gradual. More like going down steps vs going down a ramp. What I have yet to figure out is how to isolate it :dunno:, to see if it is the issue.

Hatch light is definitely not the cause.

 

[3p141592654]

My interior light dims in steps too, always done that. Working as designed.

250mA draw is way too high though, you'll find it.

 

[mstgeer]

Ding, ding, ding we have a winner!! Stew and Dan were partially correct. The POS sony deck has an internal short in it that appears to have fried the tuner in it. Pulled it out and very little draw, plug the factory radio back and all is functional. I knew not cutting the factory connector off would pay off in the end.

Serves me right buying Sony JUNK, never again!!!

Obviously this is not the right category but...what head units do you guys recommend? Would like double din touch screen with Bluetooth streaming audio.

 

[stew_7mgte]

Electrical problems are so hard to diagnose especially over the internet. Whenever i get a car with an electrical issue i go straight to the customer/owner and ask them if they have made any changes recently or what stopped working. 9/10 times i figure it out right there. Happy you found your problem.

 

[Dan_Gyoba]

I've been happy with my Alpine audio stuff. I'm very picky about audio quality, but I'm also happy with the iPod control user interface, and the Bluetooth functions. I have a cheaper unit in my DD, and as such I appreciate small details like pausing the audio when the phone rings, a complete listing of album, artist and song titles, including full UTF8 character set, and things just... working. The Alpine unit hasn't let me down. It's an older unit now, and doesn't have video, but the details of the user interface have definitely won me over.

 

[mstgeer]

thanks for the feed back.

Looking at: mainly want streaming bluetooth for Pandora, I don't use ipod.

Eclipse 7" AVN-726E DVD/Navi (used) seems they are a little behind the times but have excellent screen and audio quality
JVC KW-AV70BT
Kenwood DDX719

 

[te72]

I've had a few Pioneer units over the years, always been very happy with them for the most part. I think I have an Alpine in the MkII, and for as basic as it is, it is actually pretty versatile.

 

[mstgeer]

I was initially considering a pioneer, but their screen quality was not getting good ratings. I ordered the jvc over the kenwood because it has a removeable sceen and the kenwood did not. Also learned that jvc and kenwood are the same company.