Electrical Drain vs. Headlight Relay?

sck_nogas

sck_nogas

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Staff member
Howdy! Brand New Delica owner here!

This weekend, I got my 1991 Delica Super Exceed with Crystal Lite Roof and the previous owner had installed a quick battery disconnect to "fix" the problem of an electrical drain. If you stop the car for more than 2 hours, you need to disconnect the battery otherwise you can't start the car. :(

So, last night I broke out my trusty multimeter and moved the + over to the fused 10A connection and proceeded to do a "pull and peek" diagnostic.
  1. Disconnect the negative battery cable.
  2. Turn the car off and take the keys out
  3. Make sure you have the door switches closed (I used clamps and some wood) to make sure that you don't have the overhead light on.
  4. Connect the negative probe of the multimeter to the negative terminal of the battery
  5. Connect the positive probe of the multimeter to the disconnected negative cable that went to the battery.
  6. Switch your multimeter to measure vA and look at the amount of drain currently going on.
  7. Now pull out one fuse or fusible link and look at the amount of drain currently going on.
  8. If it's still draining, then put the fuse or fusible link back in and try a different one.
  9. Once you pull the "right" fuse or fusible link, the current drain should drop to 0.
  10. Now, you now which circuit is having the problem. If you can live without that thing, then don't put the fuse back in!
  11. If you must have that thing, then you need to find where and why that drain is occuring.
In my case, none of the fuses under the steering wheel were the issue. But, when I pulled the Lights fusible Link above the battery, the issue went away!

So, I dug out the wiring diagrams and traced the connections. Hmm, think it might be the Headlight Relay. Let me go find that!

Well, here's what I saw.
IMG_6511.jpg IMG_6512.jpg​
There was a loose wire in this "home made" relay, and I re-crimped the connection and the drain appeared to "go away", but the low-beam headlights are always on?

Okay, I can live with that, but this morning (12 hours after I "thought" I fixed this) the battery is dead again!

So, any ideas on what this relay contraption is? Any ideas on what I need to do next? Am thinking I should try to replace the relay but don't know what the "weird" yellow bit that's zip-tied to it is doing?

Thanks,

Scott
 
Hi, I'm new to this forum though a 6-year delica owner. I'm experiencing the same prob you're deescribing, and I'm wondering if you resolved you're issue. A Delica specialist is suggesting I install a battery kill switch rather than try and hunt down the problem that is draining the battery. Have you experienced any probs arising from your kill switch?? Thanks - michael maser
 
Welcome! I did diagnose the problem! But, I had to get "creative". I traced as many things in the wiring diagram as I could and got NOWHERE... Everytime, I pulled a fuse, disconnected a switch, etc... the voltage draw stayed the same.

So, what I did was this...
  1. Connected a battery charger to the battery and let it trickle charge the battery all night while my car was parked outside.
  2. The next morning, used a FLIR One connected to my iPhone to find the heat source.
    • The rationale for this is that if I'm draining a few amps consistently, then something is going to be warmer than the rest of the car.
    • Also, if you don't have a FLIR One or similar heat camera, you could use a laser thermometer to do something similar, but would take longer as you can't easily visualize the area.
  3. Then I looked around the car to try to find Mr/Mrs Hot spot.
    1. Looked at the dash, no excess heat
    2. Looked at the relays, no excess heat
    3. Looked under the dash, no excess heat
    4. Looked at the top of the engine, hmmmmm...
      1. The battery is slightly warmer at 80F - Duh, it's been draining for 12+ hours...IMG_5156.jpg
      2. The engine is cool at 79FIMG_5157.jpg
      3. The Battery charger is hot at 96.5F - Duh, it's been charging for 12+ hours...IMG_5158.jpg
      4. But, something down in the bottom of the engine compartment is quite hot! 108F!!!IMG_5159.jpg
    5. Let's crawl under the car and look!
      1. Hmm, the tailpipe is still warmer than the rest of the car at 82.3FIMG_5160.jpg
      2. But, let's look at the alternator.IMG_5161.jpg
      3. HOLY CRAP! That thing is absolutely glowing!
So, with that I guessed that the diodes in the alternator were toast and I should replace/rebuild the alternator. Well, could not find a place with an existing alternator to do a swap, so I bought a new alternator off Amazon. Then I wrote up all the steps I needed to do to repalce the alternator in this thread.

Once the alternator was swapped out, the drain went away! Had to replace the battery since it was killed after so many complete discharge/charge cycles and I have not had any electrical system issues since. Though I do recommend using a voltmeter to monitor your car. I am using a USB charger/Voltmeter in mine.

Good luck, and let us know what you find!
 
Wow, that's very diligent on your part! I just talked with two different mechanics who both approved of the battery -kill - switch option instead of spending a lot of time trying to track down a phantom drain. I don't really have that kind of time to spare right now but I do need my van back on the road! I also printed off your multimeter-forensic suggestions, so thanks. When I get more time I am curious as to whether I'd even find the drain. Cheers.
 
I hadn't seen this post for some reason. The relay thing is probably a daylight running light mod required in Canada. If I were you I would replace the voltage regulator w/in the original alternator and keep it as a spare... I've heard of the cheaper aftermarket alternators not lasting long at all.

OEM# MD611668/611481, cross search replacements
 
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And I meant the ground battery terminal; in fact, I tried wiring into either battery (which are joined by a coupling cable) and I still couldn't kiil the juice.
 
I bought a 2nd switch (they weren't expensive) and wired it into the other ground cable and that shut off the power - so I'm in business. Thanks again for your suggestions.
 
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