WRX Cannot Jump Start Another Car

[Henry Paul]

How good are your cables?

I had the same problem with my jeep Cherokee jumping an Isuzu trooper. Turns
out the el cheapo Wal-Mart cables couldn't pass enough current to do the
job. I got out the set I bought at checker and it went the first time.

 

[Rick Courtright]

The inability to jump another person's car seems quite odd to me... I know
there is a connection because their lights start working again (not to
mention the fact that there are slight sparks as the last negative is placed
on the dead car's ground) but their starter motor simply will not turn over.

Any idea what condition THEIR battery's in? I've experienced what you
describe jumping cars with virtually totally dead batteries (old and
weak BEFORE they left the lights on all night) in very cold conditions
(gotta be careful a dead battery's not frozen, too, if temps are down
there), but OTOH I've also been able to get a Cummins diesel (Dodge p/u
variety) with a reasonably sound battery going from an old VW Bug
(generator model), so I don't think it's a "size" issue. Sometimes the
dead battery takes a while to build up enough charge that some of the
juice can get to the starter instead of being sucked up by the battery.
Lights working aren't the best test cuz they take relatively little
current compared to the starter--but since they do tell you current's
getting to the receiving end, try letting your car run a while before
hitting the key on the dead one.

Rick

 

[MikeL]

Twice in as many weeks my friends have had the misfortune of need a jump
start. I offered, as I always carry cables, but my new car won't seem to do
it. (YES, I know how to hook up the cables). Even with my engine running
and revved to around 4k RPM I still cannot jump anyone else's (smaller)
Honda.

Does the WRX have a weak battery? Is there something I need to know about
the car's electrical system?

The inability to jump another person's car seems quite odd to me... I know
there is a connection because their lights start working again (not to
mention the fact that there are slight sparks as the last negative is placed
on the dead car's ground) but their starter motor simply will not turn over.
Even a small 4 like in the WRX should have enough juice when revved to jump
another small 4-cyl car.

Thoughts?

Mike

 

[Edward Hayes]

If the opposing cars battery is shorted and will not take a charge then any
car battery can't overcome this very high load. ed

 

[Ragnar]

How good are your cables?

I had the same problem with my jeep Cherokee jumping an Isuzu trooper.
Turns out the el cheapo Wal-Mart cables couldn't pass enough current to do
the job. I got out the set I bought at checker and it went the first time.

I've had that happen as well. The cheapo cables actually got really warm
before I gave up. Better cables worked fine.

 

[GW De Lacey]

Twice in as many weeks my friends have had the misfortune of need a jump
start. I offered, as I always carry cables, but my new car won't seem to do
it. (YES, I know how to hook up the cables). Even with my engine running
and revved to around 4k RPM I still cannot jump anyone else's (smaller)
Honda.

Does the WRX have a weak battery? Is there something I need to know about
the car's electrical system?

The inability to jump another person's car seems quite odd to me... I know
there is a connection because their lights start working again (not to
mention the fact that there are slight sparks as the last negative is placed
on the dead car's ground) but their starter motor simply will not turn over.
Even a small 4 like in the WRX should have enough juice when revved to jump
another small 4-cyl car.

As others have suggested, it's most likely nothing to do with whether
your vehicle is or isn't a WRX. The most likely culprit is the cables.
If the other battery is dead flat and your cables are incapable of
carrying sufficient current, then the other car won't start until some
charge has built up in its battery. If the other battery is in a state
where it permits a dead short, then the other engine won't start,
period.

On the subject of cables, the best set I ever had were made from
industrial strength welding cables and heavy duty clamps. There was
virtually nothing 12 volt that you couldn't jump start with those
babies.

A lot of people think that revving the engine helps the jump start
process. It does a bit, but for different reasons than commonly
believed: if the alternator is charging there is a reduced likelihood
of a voltage surge burning out delicate electronics; and if your
cables are of the el-cheapo variety, running the engine will keep the
voltage up in your battery while the amps are struggling through the
cable to charge the other battery.

 

[Grug!]

I have had the same problem with my 98 GX impreza using the user manual's
connection suggestion of hooking the negative jumper cable to your lifting
ring of your engine (or some other bare metal earthing point) it couldnt
get anything started..

But since ive jumped cars a few times i decided to try the negative cable on
the negative point on my battery.. the dead car started instantally. i didnt
even need to rev my motor (even though i did.)

So are you connecting your negative cable to the chassies or the battery?

Secondly i noticed that my battery has a plastic ring around the base of the
terminals and it seems to be exactally in the same place as i keep trying to
connect the cables leaving me with a kind of half connection, could this be
your problem?

and of course i should add that i am using jumper cables that are capable of
jumpstarting a mack truck off another mack truck.

The battery of the other car shouldnt be too much of an issue as you are
probabally attaching the cables to the dead car in such a way that connects
the jumper cables to the actual power cables in the dead car.. so therefore
you might find, if the dead battery is really really buggered, that the dead
car starts but stops soon after disconnecting the jumper cables..

just my 2.2 cents (gst included)

James
Australia

 

[John O]

Thoughts?

I'm not an auto mechanic, but I do have a lot of experience with electronic
charging circuits, and more experience jumping cars (being a recipient) than
I'd care to admit. Good cables help a lot, but good connections with the
clamps are more important.

IMO, you should use the jumpers to charge the other battery...and you should
NOT use the cables to power the starter on the dead car. Trying to turn the
starter of the other car requires big amps, big cables, and a solid
electrical system in the first car. I wouldn't do that with the first car
running, I'm just paranoid about the risk of damage to the electrical
system. I've done it lots of times, be on hearing a few stories of wasted
electronic systems, I've become paranoid.

For charging, running 10-20 amps through cheap cables isn't a big deal, and
should charge the battery fairly quick. As in, a few minutes. Be patient,
let it charge. Mike mentioned revving the engine, and just as important is
turning off ALL the electrical stuff in the running car. The first car MUST
have a higher voltage than the dead car, and fractions of a volt matter.
Current won't flow otherwise, and the bigger the diff the faster the charge.
A voltmeter tells the story.

-John O

 

[Danny Russell]

I'm not an auto mechanic, but I do have a lot of experience with electronic
charging circuits, and more experience jumping cars (being a recipient) than
I'd care to admit. Good cables help a lot, but good connections with the
clamps are more important.

IMO, you should use the jumpers to charge the other battery...and you should
NOT use the cables to power the starter on the dead car. Trying to turn the
starter of the other car requires big amps, big cables, and a solid
electrical system in the first car. I wouldn't do that with the first car
running, I'm just paranoid about the risk of damage to the electrical
system. I've done it lots of times, be on hearing a few stories of wasted
electronic systems, I've become paranoid.

For charging, running 10-20 amps through cheap cables isn't a big deal, and
should charge the battery fairly quick. As in, a few minutes. Be patient,
let it charge. Mike mentioned revving the engine, and just as important is
turning off ALL the electrical stuff in the running car. The first car MUST
have a higher voltage than the dead car, and fractions of a volt matter.
Current won't flow otherwise, and the bigger the diff the faster the charge.
A voltmeter tells the story.

-John O

I agree whole heartedly with the above. Also, do not let the other person (the jumpee) near the
cables! Remember: it's YOUR charging system at risk. -Danny

 

[Hallraker]

I agree whole heartedly with the above. Also, do not let the other person (the jumpee) near the
cables! Remember: it's YOUR charging system at risk. -Danny

I learned this the hard way a couple winters ago. I often get out of work
late, especially during the winter, and so I'm the last, or nearly the last
one out to the parking lot. During a particularly cold week, I went out and
saw at least one person every day, often more, stranded out there in
frustration. I jumpstarted probably two dozen cars that winter, most of
them during that week. Anyway, a couple days later I'm driving down the
road and the Subie just dies. Turns out I'd torched the alternator doing
all that charging, either that or someone had a faulty electrical system.
Don't know how it happened, but it pays to be careful.

-Matt