Last week I had to get my car jump started. Fortunately, I hadn't installed my Empeg yet. Fortunate because the guy on the other end of the cables got it wrong.

Net result: Lots of dead electronics. The biggest apparent hit is the factory Infinity sound
system. Dead as a door nail. I Don't have a tally yet on the total amount of damage.

Can any one recommend additional precautions to take, re the install of my Empeg.
( I've already sworn never to allow any one else to touch the jumper cables. )

I don't mean to state the obvious here, but you did check all the fuses, right? It's possible your sound system is fine. That's what fuses are for, to protect against this sort of thing.

Scary part is, if the jump really did fry your factory sound system, there's nothing else you can do to protect the Empeg other than installing fuses on the power lines.

___________
Tony Fabris

Well, the fist thing to connect to the monster cable running from the battery to the amplifiers is the fuse, and if you have multiple amps, then a good power distribution block has a few fuses in it as well. (Especially if installed by professionals)

As Tony stated, check the fuses, they are likey what is shot. And while you are at it, better check ALL your fuses, you never know what fuse 18a does till you need your airbag!

Cheers, let us know what the total fuse-body-count is.

Smoker_Man
#080000449 MkII - 36Gb Blue

Scary part is, if the jump really did fry your factory sound system, there's nothing else you can do to protect the Empeg other than installing fuses on the power lines.

Err, wasn't it the case of reversed polarity? Woldn't beefy diodes in power and ground lines help?


Dragi "Bonzi" Raos
Zagreb, Croatia
Q#5196, MkII#80000376, 18GB green

I'm no car expert, but I would lay my left one on the line to say that the auto manufacturers would have though of John Q Public reversing the polarity to boost an auto, and as such, droppped a few diodes and ground lines in. Not to mention the fact that a nice big reversed charge *might* pop the top off a nice battery.
Anyone who is a mechanic care to set the record stright?


Smoker_Man
#080000449 MkII - 36Gb Blue

Well, since whatever you connect as a feed to the battery has to pass through the alternator, which usually haas a diode based regulator attached, I would have thought you have fried a few didoes in the alternator. I doubt that the reverse on the battery would have done anything; however, if you then tried to start the engine afterwards without checking the alternator, there's a good chance you fried your electronics by a big, unregulated over-volt when you started the engine again (possible without the regulator). Sorry, it's bad news, I would have thought...

One of the few remaining Mk1 owners... #00015

No visibly blown fuses. Guess I'll have to break out the multimeter. I do so hate digging around behind the panels of new cars. The last car I had, where the owners manual had a decent wiring diagram, was a 77VW Scirocco.

Here's a strange item, the power door locks work from the remote, the lock/unlock switches inside the car don't.

Glenn

You've not actually said what car you have, yet. It sounds as if there is some damage to a central card with a lot of auxilliary electronics on it; can you go through what does and doesn't work?

Also, have you got an injected car? Finally, is it under warranty?

One of the few remaining Mk1 owners... #00015

Sorry about the lack of info.

Its an 86 Seibring Convertable. I'm afraid the warranty expired long ago. I've been riding a commuter bus for the last 2 years, hence the dead battery every now an then. I don't think the injection system was badly harmed, the car starts and runs.

Sorry Rob, the feed doesn't have to pass through the alternator, and anyway, the diodes in the alternator are only the to convert the *alternating current* that the alternator generates into good old DC. Any DC feed you put in isn't going to go anywhere near those guys. The alternator is normally attached in parallel to the battery.

Fried electronics when jump starting cars these days is a very real risk. Most car manufacturers say you shouldn't do it unless you use special jumper cables with a dirty big supressor built into them, and even then you've got to connect and disconnect the cables correctly. Anybody noticed nice big sparks from old fashioned jumper cables when you connect or disconnect them? Electronics don't like that sort of stuff!

If you want to protect your expensive stereo gear from people jump starting your car then I would suggest either *not letting them do it* (you could perhaps keep a battery inside on the charger. Actually sounds like it might be getting a bit sad anyway if it goes flat that fast) or build in some meaty supressors and diodes into your stereo power supply system. This last one still won't protect the other electronics in the car though.

Good luck getting everything going again!
Derek

(list 6284, Mk1 S/N 00299 4GB blue [for sale]. Mk2 S/N 080000094 6GB blue)

The alternator is normally attached in parallel to the battery.
Yup, the diodes give the battery DC (which it likes) instead of AC (hich kills it in short order). What I meant was (and explained badly) that each AC Delco/Lucas/Valeo alternator I have come across that includes both rectification and regulation, has some polarity reversal protection built into the alternator to stop the regulator blowing (unlikely as that is) when the voltage reverses. In theory, the diode(s) they choose is usually up to taking the inrush current for any inductive loads that might still take current in the event of a reversal. I have even blown one (expensively) in a rather stupid attempt to reverse my battery, to prove it

I also agree about the sparks - but by the time you see the spark, it's already too late as it implies a back EMF as the load disappears - but then, you can avoid the situation occurring by connecting the leads in a definite order, and when the jump has succeeded, taking them off in reverse. I have done this on literally hundreds of cars, most of them modern, and I have had zero failures.

Finally, I only ever do my own jump starting - that's why I carry a set of specially rigged & taped set of start cables in each car!

PS Have you sold that Mk1 yet?

One of the few remaining Mk1 owners... #00015

Greetings!

Has anyone used / tried those portable, disposable jump start kits? Basically, it is a self contained device the size of your hand. It plugs into your cigarette lighter and supposedly charges your car in about 20 minutes. It is not designed for very heavy draw vehicles (big trucks, etc.), but I carry a few of them in the car. This way, I just give the person the device and drive off... I have never had to use one in the field myself yet...

Paul G.
SN# 090000587 (40GB Green)

Sorry Rob, the instructions were for gbeer. Figured you would probably know which end was which when it comes to jump starting, what with you being an owner of quality British cars and all

And unfortunately I haven't found a buyer for my Mk 1 yet either . Almost though I had one of the guys at work convinced, but he's chickened out. If you know of anyone who can give it a good home let me know! (I could even deliver it to someone in Holland personally!)


(list 6284, Mk1 S/N 00299 4GB blue [for sale]. Mk2 S/N 080000094 6GB blue)

In reply to:

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...you can avoid the situation occurring by connecting the leads in a definite order...

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Which is?

I seem to remember being told negatives first in any order, then positive on the dead battery and then the other end on the battery in the car with the running engine.

C'mon, tell me if I've been doing it right all these years.

Nick.

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18Gb AR red - s/n 080000299 (original pos'n 8724). Reproduction of this mail is not permitted.

C'mon, tell me if I've been doing it right all these years.

Yup, dead right. By doing the earths first, you common the 0V DC level, and then by doing the dead positive first, you prevent a discharge (spark) as you connect the positive from the running engine to the flat battery of the dead one. The spark is the killer.

When you unwind, you first stop the engine of the car providing the jump, then take the cables off in the reverse order.

One of the few remaining Mk1 owners... #00015

Strange, my jump leads say connect positive first. I suspect this is because if you slip with the + lead, having already attached the -, you're likely to short something. Slip with the - after having attached the + and you'll just complete the circuit correctly.

Hugo

Thought I'd wrap this up. The Sebring is back to normal.

Total damages $435us.
New battery, new switch panel in door, and yes some fuses. (I swear I looked, honest I did.) But about $150 of that was to replace a leaking oil gasket that I noticed while poking about under the hood.

glenn