any tips on how to jump start

[Vandude]

I went to start my Toyota van and nothing happened when I turned the key, no sound or anything. All the dome lights were not working. I think I might have left one of the doors ajar and the door light stayed on. Anything I should check first before trying to jumpstart it? I read that the alternators are bad on these vans, should I do any checks on that? Thanks

[s_e_a_n_s]

I've got no particular expertise, but recently went through a round of starting/charging problems...

• If you have the option, it's better to give the battery a full charge on a charger vs relying on the alternator to do it (which may never happen if the alternator is weak or bad). Sitting with no/low charge will shorten the life of your battery. Many auto part stores charge batteries for free, and chargers are pretty cheap.
• If I have the option, I don't like jumping a dead-flat battery. A battery will do everything it can to equalize voltage. This can mean a lot of current through the jumper cables - hot/melting cables/connectors, drained donor battery, or worse.
• After your van will start/run, check your alternator health (more below).

--- An (over-)simplified alternator test procedure... Someone smarter will find a better posting already existing on a different thread.

I usually measure voltage at the cigarette lighter, as it's (marginally) convenient, but it can be measured anywhere. Start by turning most accessories off (blower fan, headlights, A/C, defroster, wipers, etc).

1. Measure voltage with the key off.
2. Start van, measure voltage at idle, then rev a little bit to see if it changes.
3. Turn on headlights and fan. Measure voltage, then rev a little bit to see if it changes.

Based on your measurements in #1/#2/#3 above:

• If your voltage doesn't increase after you start the van (#1 vs #2) , your alternator is likely bad.
• If your voltage doesn't hit ~14.5 volts, either your battery is low or your alternator is weak. With a charged battery (12.5V+), the alternator should be able to put out:
  
  • ~14.5V at idle, with accessories off (#2, at idle)
  • ~14.5V loaded when you increase the RPMs (#3, rev'ing)
  
  
• If your voltage reads 15V or higher, your alternator is overcharging (bad alternator or bad 'sense' wire to alternator)
• If your alternator is charging normally and your battery keeps going dead, it's likely a bad battery.