Reversing Battery Polarity

Randy in Maine · Post by **Randy in Maine** » Wed Oct 14, 2009 9:19 am

Well OK.

I still like the red + cable.

I also make sure that I get to be the person hooking up the jumper cables. My bus, my alternator. No exceptions.

dtrumbo · Post by **dtrumbo** » Wed Oct 14, 2009 10:26 am

Amskeptic wrote:Typical American generic positive is red (+).
Honest OEM German Positive is black (+).
Typical American generic negative is black (-).
Superior and correct German Negative is brown, like Earth (-).
Colin

I just bought some 16ga brown wire at my local NAPA. I put it on the counter and declared "Official Volkswagen ground wire". The guy behind the counter was floored when I told him that in a VW, ground is brown and black is hot. I guess he would be classified as 'typical American'.

VWGirl · Post by **VWGirl** » Wed Oct 14, 2009 2:35 pm

Randy in Maine wrote:Well OK.

I still like the red + cable.

I also make sure that I get to be the person hooking up the jumper cables. My bus, my alternator. No exceptions.

I hooked it up, he was supposed to be just "checking". I had no clue he'd move it, especially without telling me. Won't happen again. This is why I don't take my VW's anywhere to be fixed either. It never works out well.

As for the alternator charging, again I drove 100 miles in the dark and the H4's were bright as could be. It's possible it's not, but with the lights shining bright and it starting on it's own, I'd guess it is.

I will know next week when I get back there.

Hippie · Post by **Hippie** » Wed Oct 14, 2009 5:52 pm

VWGirl...just shut off the motor at night with the lights on. If there is no difference in brightness between revving up and not running, you are not charging. It helps to be pointed at a white wall.

twinfalls · Post by **twinfalls** » Tue Nov 03, 2009 8:03 pm

I don't buy the "No jump start on FI engines".
Whatever engine, I see no issue about jump starting.

Sure too high voltage is deadly for electronics, but this is about surges or transients, much over 12 volts.

NO way a deadly voltage can occur jump starting in the usual procedure.

What is highly dangerous for electronics is running the engine while there is no hooked battery. This doesn't happen in the usual jump starting procedure.
Batteries do keep voltage under 14v ( at most 16 volts, on a bad regulator ); Electronics is designed to stand much more ( over 25v, I guess ).

BTW A trick to never again reverse polarities.
Step 1 connect red cable clamps at + battery posts.
Step 2 connect black cable clamps AT BODY CAR PARTS.

chitwnvw · Post by **chitwnvw** » Tue Nov 03, 2009 9:59 pm

Hippie wrote:VWGirl...just shut off the motor at night with the lights on. If there is no difference in brightness between revving up and not running, you are not charging. It helps to be pointed at a white wall.

Do your head lights turn on with the motor off? None of mine do, just running lights.

Post by **Sluggo** » Mon Nov 16, 2009 10:24 am

chitwnvw wrote:
Hippie wrote:VWGirl...just shut off the motor at night with the lights on. If there is no difference in brightness between reving up and not running, you are not charging. It helps to be pointed at a white wall.
Do your head lights turn on with the motor off? None of mine do...just running lights.

Probably meant key in on position with engine off.

chitwnvw · Post by **chitwnvw** » Mon Nov 16, 2009 10:32 am

I believe he has a '69, thought maybe that the older bays were different.

Post by **Sluggo** » Mon Nov 16, 2009 10:43 am

chitwnvw wrote:I believe he has a '69, thought maybe that the older bays were different.

Never been in a '69 (Bus that is) but I had a friend with a late '50's bus when I was a kid and his lights were just like ours. Man that thing was a POS!

VWGirl · Post by **VWGirl** » Tue Nov 17, 2009 12:41 pm

The bus made it to FL and back (in the dark I might add) just fine. The only issues, still no gas gauge or radio. I picked up a spare in-the-tank gauge at the show.

However, the "hiccup" of cutting out for a second or two driving down the road is back. I replaced the coil again since that seemed to fix the issue the last time. This new coil was leaking so I thought that could have been it. It did it less, but still did it two or three times in the last 400 miles of the trip. I don't think it is related to the reverse-jump-starting the bus as the issue has been there the entire time I have owned the bus. It happened for the first time in Indiana in 05(?) and has been totally intermittent and almost non-existent ever since, but has shown its presence more so since I got the bus back on the road a couple of months ago. The first time it was the coil going bad. It got to the point that the bus wouldn't run. Then after replacing the coil I got a trouble-free 1000 miles out of it. Then 100 more of worrying if it was going to die on me. Then 400 of being fairly confident with the new coil I would make it home, but still freaked me out every time it did it.

chitwnvw · Post by **chitwnvw** » Tue Nov 17, 2009 1:01 pm

Is it possible some other part of your electrical system is causing your coils to destruct? Maybe you are seeing symptoms rather than problems.

VWGirl · Post by **VWGirl** » Wed Nov 18, 2009 6:36 am

Possible, but where to start? I guess this is why people put carbs on their buses? I'll just carry a spare control unit... or two.

Post by **Amskeptic** » Wed Nov 18, 2009 9:59 pm

VWGirl wrote:where to start? I guess this is why people put carbs on their buses? I'll just carry a spare control unit... or two.

That is the problem. People put carbs on their buses to try to fix a coil problem. Or they swap in a new FI control unit to fix a coil.

Where you start is at the beginning, a nice careful plan of removing variables in each system that you must check one at a time. If you flit around, you will confound variables and yourself.

Start with ignition system, if you get this bucking on the road, wiggle the ignition switch for example, to see if it is the cause. Then track back to the coil. Check the wire that goes through the distributor, many times I have seen the little green wire from coil to condenser/points short out at the hole in the distributor, right inside the gray plastic plug.

Control units on FI rarely go bad, but the connections inside the Big Plug sure do. People slop that connector on so sloppily that it bends or pushes the terminals back down the connector. Easy enough to see . . . if you are looking. Double relay ground and connectors, fuel pump wiring where it leads through the harness and at the pump, it is all there to be discovered.
Colin

VWGirl · Post by **VWGirl** » Thu Nov 19, 2009 9:06 am

Perhaps, but it is sometimes 1000+ miles before it will do it again and it only does it for a split second so it is not something you can diagnose at the time. If it is the ignition switch and I hit a bump it could cause it but the connections are tight, dry and not corroded (I checked). I don't drive with a gazillion keys on the switch. I've checked all of the aforementioned connections and they are all good. Someone suggested I take apart the double relay and clean the contacts in there. That's about all I haven't done, aside from rewiring the whole thing. I think I may have a spare wiring harness somewhere too, but replacing parts could just complicate things further. It's almost as if I have to wait for it to die completely so that I can fix it, 'cause otherwise it fixes itself in a second.

twinfalls · Post by **twinfalls** » Sat Nov 21, 2009 12:22 pm

VWGirl wrote:It's almost as if I have to wait for it to die completely so that I can fix it, 'cause otherwise it fixes itself in a second.

I've been there, about electronics troubleshooting.
The trick was to help it go bad, heating with a hair dryer at potential culprits.

Itinerant Air-Cooled

Itinerant Air-Cooled

Reversing Battery Polarity