2006 Chevrolet SSR Chevy

SEAN03

MEMBER
2006 CHEVROLET SSR
6.0L
V8
RWD
AUTOMATIC
100,000 MILES

Hi I am having a problem getting my 2006 Chevy SSR to start. I put the key in turn it and all it does is clicks. So I assume the battery is dead. So I have it charging overnight. Now if I go out tomorrow and try to start it and it does the same thing then I need to dig deeper. The problem with this truck is the battery sits all the way in the rear under the rear axle in a battery box that drops down. I really don't want to crawl under and take it all apart to see how many volts are at the battery. Under the hood their is a red terminal box and the ground is metal near the alternator. If I take a volt meter and put the positive lead on the positive box and I take the negative lead and put it on the ground near the alternator will this give me the battery voltage. My next question is I took the alternator out to get it checked. Napa advanced autozone and oreilly can not test it because they don't have the right cord or program for it. Is their a way of testing it if I find out that the battery is good. Last question is the starter which I hope not but is their a way of testing it with a voltmeter or some other way. I hate this design. It makes it bad for people who like to work on cars. Me personally. I love the older cars and I am young. They are so much easier and their is less electrical junk in it. Thanks.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Boy, I hear you about older cars. For me it's the unnecessary use of computers for things we used to have but didn't need computers for, like power locks and windows. I drive an old rusty, trusty '88 Grand Caravan as a daily driver in Wisconsin, the road salt capital of the world. My newer cars sit because I don't trust them as much.

Anyway, when Chrysler sticks the battery in a really stupid place, they provide jump-start terminals under the hood. Those are connected right to the battery so testing can be done there. You will also have an under-hood fuse box with a smaller positive battery wire connected to it. You can use that, and you can use the larger output wire bolted to the back of the generator. A fully-charged battery will read 12.6 volts. If you find around 12.2 volts, the battery is good but it's discharged. If it has a shorted cell, you'll find closer to 11 volts. For ground you can use the engine block or a paint-free point on the body, like a ground screw.

The next test is the same, but with the engine running. You must find between 13.75 and 14.75 volts. If it's low, suspect the generator. If it's a little high, suspect the generator too. Normally when it's low you won't see any change between engine off and running. When it's high, it's usually because there's one bad diode of the six. That will result in the unit producing a maximum of exactly one third of its maximum rated current. 30 amps from the common 90 amp generator isn't enough to run the entire electrical system under all conditions, so the battery will have to make up the difference, until it runs down. These are three-phase generators, and with a bad diode, you'll be missing one phase. That makes "ripple" voltage very high. The voltage regulator may respond to those dips resulting the average output voltage being a little higher than 14.75 volts.

I don't know what's different about your generator that they can't test it, but GM did have a huge problem with them starting with the '87 models. They develop harmful voltage spikes due to their design. Those spikes can destroy the internal voltage regulator or those diodes. It's real common to go through four to six replacements in the life of the vehicle. To reduce the number of repeat failures, replace the battery at the same time unless it is less than about two years old. As they age they lose their ability to dampen and absorb those spikes.

The voltage test is just the first part in testing a generator. They also should be tested for maximum current output and that ripple voltage I mentioned. You need a professional load-tester for that.