jumper leads

[Dirtbag]

If your jumpering an EFI car, should you be using those protected jumperleads with the circuit breakers in them? I had them reccomended to me by someone who said using normal jumperleads could fry my electronics if something went wrong

[ee904age]

It's definately reccommended, but more as a precaution. Ive never used protected leads on any of my EFI cars and never had a problem touch wood. Hell I even managed to get the leads back to front on my Galant and didnt do any damage.

[Quint]

If you don't have those breakered jumped leads just take the terminals off the car your jumpering from.

[sergei]

have you guys actually pulled apart the "surge protector" box (or whatever it is called)?
I did, I will tel you there is nothing to stop a massive surge going through the leads or circuit breaker. The wires are actually going straight through them, there is a zener diode, but in my opinion it is cappable passing through only a few amps. There are also other components, a capacitor (small ~0.5uF - HF filter?), couple of LED and resistors.
I believe the protecting box is actually "snake oil", and infact I don't belive that even 24V surge can fry your electrics, due to voltage regulators inside every ECU, with large capacitors and inductors to filter out the HF and AC component. And in fact most of ICs run on 5V or 3.3V (newer) in ECU, so it is defenetly behind relative complex filtering and regulators. But if you are talking about simplier devices like relays, hell then can withstand much higher voltage surges being imune to high frequency/ short duration pulses (due to high inductance).
Most circuits with IC (even 12V ones) will have some sort of filter/regulators supplying them.

Actually I've witnesed the black box setting itself on fire due to zener diode not coping with voltage difference inside (I think they use 15v zener diodes) on normal operation with alternator slightly overcharging ( probalby near 15v or so, due to cooked battery).