84 Vanagon Parasitic Draw

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Amskeptic
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Re: 84 Vanagon Parasitic Draw

Post by Amskeptic » Wed Mar 23, 2016 6:21 pm

Latest post of the previous page:

sped372 wrote:
Amskeptic wrote: Do Vanagon brake lights go on with ignition "off"?
Colin
Yes,

I'm going to pop the cover on the cruise module but doubt there will be much to be learned.
Where is it located? I didn't think much was going to present itself to me when my 1989 GL idle stabilizer failed and stalled the engine every time I hit full lock or the A/C switched on.

Turns out that the idle stabilizer module was located at the right rear tail light and had ingested some water from the scoop. Cleaned it, re-soldered a connection, idle stabilizer worked fine for the rest of the time I had the car.
Colin
(shouldn't have sold it, I cudda done the dreaded head gaskets easily, but it was 1992 and I did not have the internet)
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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sped372
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Re: 84 Vanagon Parasitic Draw

Post by sped372 » Thu Mar 24, 2016 5:44 am

It's actually tucked up under the dash pod. I popped the cover and pulled the pcb - nothing obvious to report. I'm soliciting the help of an EE friend of mine, just out of curiosity. I'm interested to know if there is a design flaw (did it always do this? I'd be shocked) or if a faulty component is to blame.

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I noted one diode that measured 'differently' on my multimeter compared to the rest (red arrow), but I didn't desolder anything from the board so the test is suspect at best.

Image
I also noted the hot (+) and cold (-) terminals for the brake monitoring circuit. This is what lets 30mA bleed at all times. I get a reading on my diode setting on my multimeter (both polarities) but no audible 'beep' - whatever that means.

Regardless, further exploration is just a novelty to me at this point. The important thing is I have eliminated the parasitic draw and won't kill my battery while parked any more.
1971 Karmann Ghia - 1600 DP
1984 Westfalia - 1.9 WBX

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Amskeptic
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Re: 84 Vanagon Parasitic Draw

Post by Amskeptic » Thu Mar 24, 2016 2:13 pm

sped372 wrote:It's actually tucked up under the dash pod. \
I also noted the hot (+) and cold (-) terminals for the brake monitoring circuit.
Wherever . . . so now you can look for any solder joints that have a small halo crack where the pin sticks through the solder and just remelt the joint briefly . . . like I did for my Lexus LS400's ECU :cyclopsani:

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BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

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