Solving parasitic draw (2 Viewers)

[HMKC]

I want to start this with I’m mechanically inclined but this is a whole new level for me. I’ve had a parasitic draw that would drain my battery within 5 days of not starting it for a while now. My temporary solution was to put a battery cutoff switch under the hood and if I knew I wouldn’t be driving for 5 days I would flip the switch to prevent the batttery from draining. I finally worked up the time to chase down the draw and here’s how it went:
First I picked up a harbor freight multimeter and got to pulling fuses. I noticed that fuse 10 under the hood was my issue- the amps dropped significantly when it was pulled. This fuse powers the following: Interior lights, personal light, luggage compartment light, ignition switch light, open door warning light, clock, radio, cassette tape player, power antenna, vanity lights

Next step was tracking down where the draw was com

 

[HMKC]

Next step was tracking down where the draw was coming from off that list. (Sorry for the cut off, first thread here) I checked every vanity bulb and disabled them no change on the multimeter. Ended up removing the whole dash to get behind and as I under every connector I could find I still saw no change. Finally I saw the connector for the ignition ring light and as soon as I disconnected it the amps immediately dropped. I left the ignition ring light disconnected and no more parasitic draw! My truck has been sitting for 12 days without being touched and started right up! Battery is showing it’s charged. If you have a parasitic draw it’s 100% worth taking the time to solve it. I spent about 4 hours taking everything apart and putting it back together but it was worth it. I should mention I went through several batteries as they would get drained and they wouldn’t last as long.

 

[tmxmotorsports]

You fixed it but did you really fix it? What is it that keeps that light on in the first place?

 

[HMKC]

You fixed it but did you really fix it? What is it that keeps that light on in the first place?

Good point, I figured the light failed from within as the light would not turn on and give off light but was drawing power. I guess time will tell if there’s a further issue. I could also order a new light and replace it one day but I don’t see myself doing that as I’m ok with being without the light.

 

[suzuguru]

Good job tracking it down!

 

[CharlieS]

Test your door switches...

 

[HMKC]

Test your door switches...

That’s a good point! I’ll check those out

 

[landcrshr]

Good point, I figured the light failed from within as the light would not turn on and give off light but was drawing power. I guess time will tell if there’s a further issue. I could also order a new light and replace it one day but I don’t see myself doing that as I’m ok with being without the light.

There's a timer module associated with the ignition switch light that commonly fails. It doesn't shut off completely, allowing a small current to trickle through the bulb. IIRC, the module is a little green cube that lives in the passenger kick panel, and it can be easily fixed by replacing removing a diode.

Good job narrowing it down, sorry it was so much work.

 

[HMKC]

There's a timer module associated with the ignition switch light that commonly fails. It doesn't shut off completely, allowing a small current to trickle through the bulb. IIRC, the module is a little green cube that lives in the passenger kick panel, and it can be easily fixed by replacing a diode.

Good job narrowing it down, sorry it was so much work.

That helps a lot. I appreciate it!

 

[george_tlc]

Ignition dimming relay

Ignition ring...

cheers,
george.

 

[Mark W]

That is a common failure resulting in a lot more draw than you might expect. The "timer" is fed from the dome/door light circuit. When it is energized it charges a capacitor . When the circuit is de-powered, the capacitor discharges into the ignition ring light until it is done. This is what provides the timed illumination. The most common failure mode results in continuous power to the ignition ring light. I have replaced several of these over the years in different '80s. I still remember how surprised I was on the first one when I realized that all the draw was from that itty bitty little light!

Mark...

 

[LandLocked93]

That is a common failure resulting in a lot more draw than you might expect. The "timer" is fed from the dome/door light circuit. When it is energized it charges a capacitor . When the circuit is de-powered, the capacitor discharges into the ignition ring light until it is done. This is what provides the timed illumination. The most common failure mode results in continuous power to the ignition ring light. I have replaced several of these over the years in different '80s. I still remember how surprised I was on the first one when I realized that all the draw was from that itty bitty little light!

Mark...

So...if the ring remains lit after removing the key - for more than [how much time?] - is an indication of the failing component?

 

[Mark W]

So...if the ring remains lit after removing the key - for more than [how much time?] - is an indication of the failing component?

The key removal or insertion is irrelevant. The ring comes on when the door is opened... with the dome light circuit... and the "timed illumination" starts when the door is closed and the dome light circuit is de-powered. So far as I know, when it fails, it stays on full time. I have not come across one what stays on "too long". If it did just stay on for too long rather than full time, the draw down would be insignificant.

Mark...

 

[LandLocked93]

The key removal or insertion is irrelevant. The ring comes on when the door is opened... with the dome light circuit... and the "timed illumination" starts when the door is closed and the dome light circuit is de-powered. So far as I know, when it fails, it stays on full time. I have not come across one what stays on "too long". If it did just stay on for too long rather than full time, the draw down would be insignificant.

Mark...

Copy that.
So an indicator of component failure could be if the ring can be seen (through the window for example) an hour(ish) after the door is closed and dome light extinguished?

 

[Mark W]

Copy that, so if the ring can be seen an hour (e.g.) after the door is closed and dome light extinguished could be an indicator of a failure?

Absolutely. I just stepped out and checked (the only rig handy right now) and it only illuminated for about 5 seconds after the door closed. This seems pretty standard for all that I have ever paid any attention too. It seems like a lot longer than that as you get in and reach to insert the key. Plenty of time.

Mark...

 

[ppc]

I spent about 4 hours taking everything apart and putting it back together but it was worth it.

Great that you were able to track down the cause of your problem.
Just a suggestion for the future, as a relatively new member of this forum you could have saved a lot of time searching the forum using Google or the forum search function for possible solutions or make a post asking for suggestions. There are no new problems that have not been documented over the many years on this forum. The better your search skills become the better the results.

 

[CharlieS]

My ignition ring drained my battery recently when I inadvertently left the driver's door open while I was doing a mirror project over a couple of days. I thought the light just stayed on as long as the door was open (hence my comment about the door switch above). I didn't even know about the relay module. Mine might be failed too. I'll go out and test it today and do some reading up. Thanks for posting this thread, it helped me identify a problem that I didn't know I had.

 

[jonheld]

My ignition ring drained my battery recently when I inadvertently left the driver's door open while I was doing a mirror project over a couple of days. I thought the light just stayed on as long as the door was open (hence my comment about the door switch above). I didn't even know about the relay module. Mine might be failed too. I'll go out and test it today and do some reading up. Thanks for posting this thread, it helped me identify a problem that I didn't know I had.

"Ignition key cylinder light relay"
Component I11 in the interior light section of the EWD. Lower right side kick panel. I believe the picture below is the part in question.

 

[Mark W]

"Ignition key cylinder light relay"
Component I11 in the interior light section of the EWD. Lower right side kick panel. I believe the picture below is the part in question.

View attachment 3576847

Yep. That's her.

Mark...

 

[dhouse]

You could test the voltage drop across the fuses. --this may be an easy way to isolate:

Another fuse volt drop chart: https://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=721311