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).


Measure voltage with the key off.
Start van, measure voltage at idle, then rev a little bit to see if it changes.
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.