Car won't start after carputer install

**UnsanePyro** · 07-19-2005, 11:58 PM

Alright, well, here is the deal. I installed my carputer yesterday, and everything went well.

Today I got up and went to work, my car started fine. Went out to get some coffee at one point, and then went out at another point to get dinner. Car started fine.

When I got out of work (about 2 hours after the last time I went out), my car didn't start at all. None of my lights were on (though maybe my door was open a bit and the interior ones may have been on). I got a jump from my friend, and it started instantly, no problems at all.

I drove it home and everything was fine. I tested the battery and it came in around 13V.

I went out about 30 minutes ago, and plugged everything in to test something out. It all ran fine. The power supply on the carputer has a feature built in where if the battery voltage drops to a certain amount, it will power off, so it doesn't drain the battery. Everything went well, but when I went to start the car, it wouldn't start agian.

I disconnected the carputer from the battery, and it still would not start, even though the voltage still looked fine.

I jumped the car again, this time with my dad's truck, it started right up and kept running after I got the cables disconnected. I let it run for about 10 minutes, and then turned it off. I went to go start it up, and I had no power to anything at all, not even the radio or lights in the dash.

None of the fuses are blown either.

Is it time for a new battery? I have no idea how old this one is. Isn't there something more to a battery other than just the voltage that determines the starting ability?

Could it be the alternator, not charging the battery? That would explain not having any power at all even after it was started and running.

I don't think the carputer drew too much power, it draws less than 60W at less than 10A (I didn't blow the fuse, and the power supply only has a max of 60W). Thats less than a sub or two.

I'm going to stop by someplace tomorrow like AutoZone and see if they can test the battery for me and see if there is a dead cell (?) and possibly get a new one.

If the battery looks fine, looks like it is going to a local guy or the dealership, whoever can fit me in first, since I am supposed to leave for vacation on Monday.

So can anyone help me out?

**Cheekz185** · 07-20-2005, 12:08 AM

Originally Posted by UnsanePyro

Is it time for a new battery? I have no idea how old this one is. Isn't there something more to a battery other than just the voltage that determines the starting ability?

Thats prolly exactly the problem. Just get a new battery. I remember a couple weeks ago a thread exactly like this was posted and it turned out to be the battery.

**EsKALad** · 07-20-2005, 01:52 AM

go to a mechanic they have a machine that tests the battery and altetnator. it seems to me your alternator might be bad!

**SAScooby** · 07-20-2005, 02:27 AM

I think in the install of the pc you may have failed to re-tighten a critical battery bolt (either the + or the -) directly on the battery and thats why this is intermittent.....

**UnsanePyro** · 07-20-2005, 08:40 AM

I don't think it is the alternator that is bad though, if it was, wouldn't the car stop running quite fast on my drive home with the radio/headlights on?

And everything was tightened back down after the install. It isn't really intermittent starting, it did for a few times, and now it doesn't any time. I made sure they were tight also after I disconnected the carputer to see if there was a problem with that wiring.

**Enforcer** · 07-20-2005, 09:03 AM

Battery most likely.

Alternator possibly.

**gommino** · 07-20-2005, 09:51 AM

How long did you have the engine running for? By the sounds of it you haven't given it enough time to charge up properly. I think the power supply's cut off feature either isn't working properly or the voltage cut off point is too low. If you can take the battery out of the car and charge it fully with a mains charger, or drive it for a couple of hours minimum (10 mins isn't enough, even without the carputer connected).

Rob.

**Bugbyte** · 07-20-2005, 09:59 PM

I like SAScooby's suggestion. It's REALLY suspicious that you've had no trouble with the battery until you messed with the electrical system.

Did you disconnect the battery terminal at some point? If so, disconnect them again, clean them with a wire brush, clean the battery terminal with the brush and reseat them. Make sure they are tight.

**wizardPC** · 07-20-2005, 11:18 PM

yeah, retighten the battery cables. I really think that's the problem, because I have done that before

**UnsanePyro** · 07-20-2005, 11:24 PM

Well, I went to AutoZone this morning and had them test the battery. They brought out a thing with two displays on it, Voltage, and I believe Amperage. The voltage side looked fine to me, 11.5-14 was what it would read. The other side though, amperage I believe it was, stayed at 0 the entire time, only going up to about .3. The test finished, and said I had a bad battery. I believed them, and bought a new one, which is working great for me now.

I got one with 640 Cold Cranking Amps (for the New England winters) and a normal 800 Cranking Amps. It has a 3 year free replacement plan, and an 8 year limited warranty.

And now, my carputer is completely, and successfully, installed.