car wont start

[vdubpower]

89 carrera

battery is a mtp 93 interstate, 4 yrs old

i try to drive the car on weekends, so it was maybe a week i had not started it

tried to start it and only dash and interior overhead lights went on, as i tried to crank they went off...
if i pressed the horn it made a weak squeal.

my brother had a ctek 4.3 that reconditions/charges the batteries so it went thru its steps and i left it on for 6 hrs and still nothing

prior to anything, i used a voltmeter and checked voltage was 12.7

i have a big jumper booster pack, but the damn jaws are too big to get around the clamps as the area is so tight

so im not sure if it isi actually the battery, or if this is an alternator or starter issue.

anything else i can consider. thanks

[rnln]

to me, it's the battery.

[DanielDudley]

Use jumper cables and try to start car if you want to test the battery theory.

Jumper the battery for 20 minutes, and then charge it. You may get a charge out of it, but modern batteries tend to die all at once. They don't hang on like old batteries did.

[T77911S]

clean the connections.
make sure you clean the grounds to the body.
don't forget the ground from the body to the tranny

[fizeus]

If just after charging you measure 12.7 it's battery.

You can still check if after charging your batteries 'keep' current.
If you see voltage drop in a couple of hours they are toast

[T77911S]

just take the battery to advance and have it tested for FREEEEEEE if you suspect the batt.

[Jesse16]

I second the cleaning all the connections item. Then just get a new battery if the current unit is not AGM and is 4 years plus old.

[Superman]

A battery with 12.7 volts is fine. The problem is the wiring. Likely one or more ground connections. The big fat cable at the positive pole of your battery goes to the starter only. The rest of the car is energized by the small wire. The connection at the other end of that wire should be cleaned, along with some ground connections. From the negative pole of the battery there is a corresponding small wire that likely connects to the chassis of your car. Clean that connection. Under the car, there is a braided copper strap that connects between your transmission and the chassis, close to the forward tip of the transmission. Wire brush the connections at each end of this.

In fact, you can use a multi-tester to measure resistance in those circuits. Many older cars could benefit from a cleaning of various connections, particularly the ground connections. Even just wiggling connections can improve them.

[theiceman]

1. Clean connections
2 jump start car
3. make sure you have at least 13.1 volts at battery while idling
4. look for parasitic drain while everything is off

[vdubpower]

thanks everyone


so how do i ground this car, someone mentioned to the transmission

if i am using one of the battery jumpers, theres not much reach to find a groundable surface, maybe the hood latch?

i cant jump from another car because itson the wrong side of the garage

you whats weird is when i have to jump my 500sel with the same battery, if i ground the neg while jumping the car it wont jump

it will only jump if both black and red are attached to both batteries...

[Jesse16]

Yea, I violate that old rule and connect to the battery terminals only. I think that was intended primarily for batteries venting a flammable gas and my battery is sealed anyway. No good unpainted metal up front to ground jumpers to that I remember. Just don't make sparks with flammables near by. Wonder if the myth-busters ever did that , like cell phones at the gas pump. A possible body ground on the 911 up front would be one of the front strut bolts.

[T77911S]

use the battery terminals

I mentioned the transmission as a place to clean the connection.

as I said, clean all the major connections. if that does not do it, charge the battery and have it tested.
stop trying to jump it. if the connections are bad jumping wont help you.

[vdubpower]

got it....to clean terminals is there any special product or just a good wipe. thanks

[fizeus]

I simply use fine sandpaper

[Bob Kontak]

Originally Posted by vdubpower

you whats weird is when i have to jump my 500sel with the same battery, if i ground the neg while jumping the car it wont jump

it will only jump if both black and red are attached to both batteries...

If I understand what you are saying there is not a good connection between the negative battery terminal and the chassis where you are grounding.

Not sure of the jumping configuration but assuming 911 provides power to the SEL.

[vdubpower]

no, when my sel would die

i typically had used my yukon denali as a donor or my e63

i would put the negative as a ground on the 500 sel as a recipient and start the process, as typical and nothing would happen

if i put neg on the neg connection of battery, no problem would start

ive never had success jumping a car with the negative being off the lead in the dead car

[DRACO A5OG]

Put vise grips on the terminals and then jumper cables on them and use your truck to jump the 911.

+1 remove and take it to a FLAPS and make sure CCA are adequate. What is the voltage after couple of hours?

[vdubpower]

What's Flap's

We sold the truck for a minivan. Lol


I'm just gonna buy a new battery today and be done with it. Pepboys has the Bosch 49 big one for 175 with agm.

Hopefully that sorts it


I did test the voltage after 24 of charging with ctek. Read like 13.8. Still didn't start

Could it just be a starter issue that we are missing

[darrin]

FLAPs is short for Friendly Local Auto Parts (store) -- Take your battery in with you (they'll need it anyway as an exchange for the new battery) and have it tested there before buying the new battery -- if it tests GOOD, don't bother replacing --

[DRACO A5OG]

What does it read after you take if off the charger, AFTER an hour or two? You see right after the charge you will get a high reading but you need to know what it is after it sits.

+1 take the suspect battery in for a CCA check.