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flat battery
pv370 - November 1st, 2016 at 07:02 PM

got a small hassle with the type 3 panelvan.
the battery is going flat after a week or so not driving so..........
process of elemination ... its the horn wiring
drawing about 40mA its somewhere in the steering column part BUT
i cant figure out how its wired.... does the earth come from the steering box, through the coupler (with a little braided wire ) up the column through the horn switch which earths to the outer of the steering column then there is a wire from the outer part (under the car again) back inside the car to a single connector which feeds down to the horn...........

the wiring diagram is useless as it doesnt show the steering column section from what i can work out.


barls - November 1st, 2016 at 07:09 PM

if its the standard wiring. it should be positive is at the horn and the wire back trough the column is the earth so when you press it earths the horn completing the circuit.
id look at the uni in the column as i remember there are two different version one is conductivity and the other is not.
there was someone recently posting about this but i can't remember if its beetle, bus or type three he was talking.


pv370 - November 1st, 2016 at 07:54 PM

thanks barls, i saw the other post but i dont know if the type 3 column is conductive or not and i dont know how to find out ????


psimitar - November 2nd, 2016 at 09:44 PM

If it has the same rubber couple as the Beetle then these can be conductive if not an OEM item. It's cos they use a wire reinforcing mesh inside the rubber.

You didn't say what year your T3 was but Vw generally across the models either used a positive brush connected to a wire coming up the hollow steering shaft and then the shaft was the negative part of the circuit or the entire shaft and column were positive and the wire down the entire length of the hollow shaft was your negative and then a copper braid linked either side of the coupler to earth.

If it's not the rubber coupler then it'll be the horn push itself. The contact plates sit pretty close together, depending on type of steering wheel, and a slight contact isn't enough to make the horns electro-magnets work but will still show a parasitic current draw.


AA003 - November 3rd, 2016 at 05:25 AM

I think that we are missing the point here. VW horn wiring cannot cause a flat battery.

Bring it up to Bowral and I'll have a look at it for you.


1500S - November 3rd, 2016 at 04:57 PM

My problem with similar results of flat battery over a 3-4 week period was caused by the drain from a CD radio unit. Radio now only with ignition on and problem was solved. Not sure how much current it was using to keep it's memory storage going but sccked enough out to cause problems.


pv370 - November 3rd, 2016 at 04:57 PM

Thanks for the input some more info its a 65 model panelvan
from what i can work out it shouldnt matter if the rubber coupler is conductive or not because the earth is sourced from the steering box via a strap to the torsion bar tube front end.
just not sure if the steering column tube is meant to be isolated from the steering shaft.
and the outer of the steering column must be insulated from the car as it acts as part of the earth path????? the wire coming up the shaft should be insulated from the shaft i am guessing with its own insulation ???
i assume the positive from the fuse box goes straight out to the horn looking at the wiring diagram.
then to operate the horn the earth comes from the horn in the wiring harness to a single wire connector under the dash.
this connects to a wire which goes out through the front of the car near the steering column and connects to the outer of the column on a tab.
form here i cant work out what goes on.......... the horn contact switch must earth to the outer of the column ??????
which must be isolated from the body of the car ?????


ACE76 - November 3rd, 2016 at 05:12 PM

Are you sure it's the horn/circuit that's "leaking" current? You could disconnect the horn (or remove its fuse) and see if it's still leaking. Leaks can be seen by touching the battery cable to the terminal in the dark, looking for small spark, and then isolating various items in turn -- or remove fuses and check for small spark there.
If you fit a NON-VW horn, they sometimes earth via the horn body (instead or as well as a terminal), and such a horn must be insulated completely from the body if used on a VW. The VW type (round; insulated body) can be bought at Burson's for little $.


AA003 - November 3rd, 2016 at 05:22 PM

To isolate the horn circuit turn the ignition off.


pv370 - November 3rd, 2016 at 05:23 PM

yeah its the horn circuit alright.......
first step was to pull the fuse then disconnect the horn (both terminals) and i still have resistance from the wire that attaches to the column outer to earth.
so its either in the horn switch or the column isloation.... (he said looking like he knows what hes talking about.. ????)


AA003 - November 3rd, 2016 at 05:40 PM

Horn only works with the ignition on unless it has been modified.

It cannot flatten your battery.


psimitar - November 3rd, 2016 at 09:22 PM

Quote:
Originally posted by AA003
Horn only works with the ignition on unless it has been modified.

It cannot flatten your battery.


Pretty sure that depends on year and model as to whether the horn was a perm live or switched.

Irrespective of that the OP needs to use the 10amp current function of his multimeter if he wants to find which circuit has current drain. A resistance test will just show if a circuit has continuity or not.

With ignition of remove each fuse in turn and touch a probe to either side of the fuses terminals. Any current being drawn will now show on the multimeter. Hopefully your meter goes down to mA or may have a separate mA setting.


AA003 - November 4th, 2016 at 05:30 AM

Quote:
Originally posted by psimitarPretty sure that depends on year and model as to whether the horn was a perm live or switched.


I have never seen a VW of any year that has a horn permanently live. It will be on the same fuse as the wiper and blinkers.

First of all get a voltmeter and check at the black wire at the horn (black is always ignition + on VWs) It should be 0v until you turn the key. If it was a permanent feed the cable would be red.

Does the horn work when the ignition is off?