Electrical problem, not starting

[Schmoo]

Okay, so I've spent a lot of time searching here, but haven't spotted anything similar so far.

 

Here's what's going on:

 

I just got a '97 Subaru Legacy Outback. It behaved fine yesterday.

 

Today it's more humid, and when I turned the key to 'on', I hear a bunch of relay clicking from under the dash, and the Check Engine Light is flashing in time with the clicking. In a few seconds it stops and things look normal, so I turn the key over to start. The car goes completely dead. All lights go out on the dash. When I release the key, the warning lights come back on again.

 

So the first thing I check is the battery. The positive post had a lot of corrosion (powder) on the terminal, so I take that off and clean it up. I put it back on (and I figured out the flashing parking light deal - push 'unlock' on the key fob). But the problem remains. I check the battery charge, but it's fine. The battery looks fairly new. The negative post looks fine.

 

Something odd I noticed: there's a fuse holder on one of the battery cables near the positive post. But there's no fuse in it. Should there be one? What value?

 

What else should I look at?

[Cougar]

It sounds like either the battery will not handle the load or there is a bad connection on the accessories wire. This wire may be a smaller seperate wire on the positive battery post.

 

If you have another battery you could try that, it would be an easy test or have it load tested. It may also be a bad wire connection to the power systems for the car. Check for a internally corrodid accessory wire or for a dirty connection at the battery.

 

As the systems draw current, the voltage drop across the bad connection feeding the systems increases. This causes the voltage to the accessories to drop. The power relays drop out due to low voltage and then input voltage goes back to normal as the current drops, until it is high enough to energize the relays again, and this keeps repeating, thus the pulsing of the lights.

 

The wire with the fuse holder sounds like an add on to something and is not stock. Hard to say what it is for. Once you get the other problem fixed you may be able to see what is not functioning and go from there.

[Schmoo]

Well, I think I found the answers.

 

I tried to start the car again today. First time, same as before. Then I started trying to shove my multimeter probes into the battery terminals in order to watch the voltage while I tried to start the car again. This time, the car started up okay.

 

My conclusion is that the terminals weren't making good contact. My "cleaning" didn't include a good scraping or wire-brushing, and I didn't have any appropriate battery terminal goo handy. These will be addressed soon.

 

Also, the issue about the extra fuse holder was solved by me happening to look under the passenger seat. I found a couple of extra-heavy-gauge power wires and a couple of RCA stereo pairs. I then looked again at the battery side and found that the wire matched. It was really nicely done, with wire loom that matches the factory style, and it went through a grommet in the firewill (near the brake booster) to look completely stock.

 

The radio is just stock, but now this is giving me ideas.

 

In any case, the good thing about the problems I have having is that I've found this forum. On the flip side, I'm now paranoid about my head gaskets (after reading a number of threads here). Hope mine hold out for a while.

[Cougar]

Well glad you got it going and thanks for the feedback. Purchasing a good battery brush and sealent will be good to have on hand for the future also. I have seen even good looking battery connections cause problems like this because of a slight film built up between the connection.

 

Enjoy the new ride.