TheSamba.com :: View topic - Pluged in battery

Mon Aug 18, 2014 7:55 am

84 with 1.9L wbx

I was all excited for the weekend & to plug her in & turn the key... i got a battery and then wend to plug it in.... no sooner had i done that then smoke started coming from the engine bay. It looks like at the alternator and then at the junction box on the drivers side near the firewall. i'll attach some pictures in a few... maybe it will help figure out what i screwed up.

Mon Aug 18, 2014 8:05 am

It sounds like something wrong at the alternator. Take photos of the wiring on the back of it.

Mark

Mon Aug 18, 2014 8:08 am

What was up with the old battery that you needed to replace it? Did you make any changes to any wiring in the meantime or just remove and replace the old battery with the new one exactly as it used to be?

Mon Aug 18, 2014 11:00 am

Not to be insulting or point out the obvious but you're certain you hooked the battery up right? I think it's pretty tough to do it wrong but you never know...when I was 14 I did just that on an old Corolla I would race in the neighbour's field. Wires instantly started to smolder...

Otherwise what does your alternator wiring look like? This or worse? There is a thread about an alternator harness causing a fire so a corroded one smoking isn't unreasonable.

If it's ratched you'll need a new harness...

http://www.thesamba.com/vw/forum/viewtopic.php?t=598934&highlight=beta+test

Mon Aug 18, 2014 12:50 pm

yeah - i'm pretty sure i hooked something up wrong...
here's the wiring at the back of the alternator...

Mon Aug 18, 2014 12:51 pm

Was that wire always hooked up to the alternator in that spot? :?

Mon Aug 18, 2014 12:53 pm

Yes, you grounded the battery to the engine!!! the connection is the post in the black plastic shroud below your fried wires!!! Hopefully all you will need is a new harness...could be bad!

Get one of these to start with and then start trouble shooting after that.
http://www.thesamba.com/vw/forum/viewtopic.php?p=7256995#7256995

Hope the ECU is ok! One of those 2 red fried wires is the power supply to the fuel injection too...

Mon Aug 18, 2014 1:04 pm

This is how it should be connected (minus the extra red wire to the right for AC):

You connected both the red and the blue wires to the body of the alternator which is a dead short through the engine, ground strap and frame back to the battery

Mon Aug 18, 2014 1:14 pm

Ouch. I think there's gonna be some more crispy bits somewhere...

What does the black junction box look like? <crosses fingers>

Mon Aug 18, 2014 1:24 pm

You also need to check and likely replace the battery to starter cable as the alt wiring hooks to the starter to complete its connection to the battery. Hopefully the starter survived!

Mon Aug 18, 2014 1:27 pm

And the ground strap from the trans to body, and any other engine to body ground strap that may be there. :(

Mon Aug 18, 2014 1:53 pm

Well sh! T

Mon Aug 18, 2014 2:07 pm

You might yet get lucky and find the damage was fairly confined.

I had a similar incident on Friday on my non-VW car. The starter developed a dead short and when I tried to start it the contacts in the solenoid welded themselves in place. In the time it took to get to the battery cut-off the cable from the battery to the solenoid was fried to the point of melting the battery lug.

This was on an old-school car with no electronics but I was surprised that all the damage was confined to just that one stretch of cable, not the starter cable itself or the grounds.

Check everything but hopefully the damage will be limited to a few cables and wires.

Mon Aug 18, 2014 3:15 pm

You let the magic smoke out of the wires, and it'll never run again.

Sell it to me. I've got $13.71 in change I dug out of the couch...

:lol:

Mon Aug 18, 2014 3:28 pm

Ahwahnee wrote: You might yet get lucky and find the damage was fairly confined.

I'm hoping so too, but even confined to the path between the alternator and battery that includes 2 cables joined at the starter. You still should replace the battery cable and (obviously) alternator cable. The battery cables on these earlier vans were undersized anyway and replaced with larger gauge on later vans so it's worthwhile to do anyway as corrosion of these can lead to slow starting. It probably had some serious heat too even if the insulation looks intact and being undersized to start with I wouldn't trust it now. Some recommend as thick as 0 AWG. take the old one out and bring it in somewhere that does wiring and have them make one up for you. Or contact thatvwbusguy and he can probably make it, or Van Cafe has one for $65 (not sure what gauge).

As dobryan said too, ground straps. Your engine ground and the battery ground straps would have carried most/all of the current and should be most thoroughly inspected. If they're original replace regardless. If in doubt go heavier gauge.

Here's hoping!

Mon Aug 18, 2014 6:05 pm

And it needs to be said, you might want to have someone else look over your work after replacing the burnt wiring and before connecting the battery again. :shock: .

Mon Aug 18, 2014 6:11 pm

shadetreetim wrote: And it needs to be said, you might want to have someone else look over your work after replacing the burnt wiring and before connecting the battery again. :shock: .

X2...super dangerous with your fuel lines pictured below the fried wiring.

Mon Aug 18, 2014 6:48 pm

Hey, bad luck, but better luck then having the fuel hoses catch on fire.
Do not feel too bad. Many people have done this over the years...it's called experience.

You can make a new harness, it is not that hard. Just make sure you use the larger gauge wiring when you do.

I have a battery to starter cable if you need one and pretty sure I have a Alternator harness here somewhere along with a voltage regulator for the Alternator. (Actually I have everything you need if you find more things fried.)

This is where taking pictures of everything works out for the better.
In your picture the blue wire will probably need looking at too.
Also, that crimped on connector on the blue wire. That works, but it is really better to slip a piece of "heat-shrink" over it to keep out the moisture because it is open on both ends. Or you could just put some clear silicone on the ends to seal it.

"Experience is a hard teacher, it gives you the test before the lesson."

Mon Aug 18, 2014 6:56 pm

The smallish gauge of the wires in the stock alternator harness probably protected the battery cables and ground straps, you might want to check them over anyway though. The replacement alternator harness you can buy from Go Westy will probably fix whatever is melted in the junction box over on the left side of the engine bay as well.

Tue Aug 26, 2014 10:42 pm

I see your other thread about fuel flow Rocketbox, I am curious how your wiring stood up/ what you had to replace?
Thanks,
GT