Battery, Brake and tail light dash lights flash on randomly

[Shaggy]

They both flash on for a split second at the same time, could his just be a crappy fuse or sumething? It just started doing it. My car is a 90 L na, no abs.

[Legacy777]

Could be that you're low on brake fluid, or it could mean that you have a bulb out in your brake lights.

[Shaggy]

I don't have any lights out and my brake fluid is fine too. I don't know what it could be? It's buggin the crap out of me. Some days it will do it like 5 times repeatidly and sometimes it won't do it at all. It's completely random. Has anyone ever had this problem?

[Shaggy]

So I take it nobody has had this problem before?

[Legacy777]

Check and see if the float in the brake master cylinder resevoir is stuck.

[Shaggy]

I'll check. The battery light just started flashing on with it too about two days ago.

[Legacy777]

Your alternator may be on its way out.

[Shaggy]

That would realy suck. I just got an alternator from the junkyard about two months ago that passed all the test at atuozone. But that doesn't mean it's not on it's last leg. The funny thing is, I dint have any problems with my other one other than it failed all the tests at autozone when they tested it so I decided to get one from the junkyard since I was broke and couldn't afford to get a new one and didn't want to get stuck on the side of the road with a dead battery on the way to work. If this one is what's giving me problems I might just get rid of it and put my old one back on since it never gave me one problem. What a bummer. I'll get the one on my car to see if it still passes the tests. Thanks for ur help Josh.

[Legacy777]

Do you know what test it failed on? It may still have been putting out decent voltage, but may have not passed a diode test.

[Shaggy]

There were three tests and it failed all three. I didn't ask wut test were wut, I just know that it failed them all.. But it still worked fine.

[Shaggy]

So the problem is getting worse.. I flipped my high beams on tonight and they gave 2 flickers and went out in the middle of town!! I flipped it back to low beams and my lights came back on. I pulled them out and they are fine. The lights are only a week old no problems till now. The dash lights have been staying on longer the past 2 weeks, not just a flicker anymore. I had my battery and alternator tested last night at autozone and they both were perfectly fine but he said I had a loose connection somewhere. I cleaned my battery posts and cables ( not much corrosion, but a little) and threw some of the grease they sell in the little packets on the posts and cables and still the same problem. Could this be a bad ground, a loose wire, anyones help would be realy appreciated.

[Legacy777]

It could be a loose wire somewhere or a bad ground. The main grounds are the ones from the battery that go to the chassis and to the engine. Check those, and also check the power wiring from the battery to the alternator and fuse box.

[Shaggy]

I'll make sure to check. Also, how do u know if a relay in the fuse box is bad.. Mainly one of the black ones. I don't know if that could be the problem but I was just wondering.

[Legacy777]

You can test the relays by connecting only the green T connectors, and turning the ignition to ON. Go and listen to the relays. Assuming they are ones that go on with the ignition, they should be clicking. If it's not, you know it's bad.

[Shaggy]

Josh, Which wire is the power going to fuse box? There is a little bundle of wires( can't remember exactly how many) that go from my battery to under the fuse box but it looks like they go into the fender area. I haven't takin he fuse box off yet to see exactly but I plan on doing it as soon as I can, just wanted a little heads up on what to look for maybe. Thanks man

So the bulbs ended up being defective and I got new ones. Work like a charm. Stilll have the lights flashing tho. I replaced both of the battery cables and started doing the ground mod. Only got the wire that goes to the drivers side strut tower in and it started raining. Still have the problem. I plan on finishing the mod as soon as I can. I was wondering where exactly the best ground mods to do are exactly. So far from wut I understand both strut towers from the battery, the starter from the drivers side strut tower( that's where the battery cable ground goes already, do I realy need to do this one?), and to the intake manifold from the battery. When looking for other grounds I noticed one that's in the bundle of wires that runs under he radiator for the lights and it connects to the body of the car just bellow the battery and also I found a different ground that connects to the fire wall. Does anyone know if hear grounds would benefit anything. Also I have checked all my wires( I think) and there aren't any that are loose. But most of my grounds are pretty corroded. This is the only thing I can think of that's making those dash lights come on and making the power surge in my car. Would like to do the ground mod completely but I'm not 100% sure exactly which ones to do.I've read the mod post about 20 times already and Becker out the pictures on there but im still not exactly sure( I feel like an idiot). If someone would like to enlighten me with there knowlege and possibly some pics of there mod it would be greatly epriciated. I got some 6 gauge wire for the mod, I know his might be overkill on money but it's realy not that expensive and I figured it wouldn't hurt.

[Legacy777]

Here's the power supply routing, there should just be one lead that comes from the battery to the main fuse box. It should tie into a post and then things get distributed from there.

http://www.surrealmirage.com/subaru/fil ... uting1.jpg
http://www.surrealmirage.com/subaru/fil ... uting1.jpg

BTW, what year and model subie do you have?

As for the grounding, just add an extra lead to the starter from neg post on bat, from intake manifold sensor ground to neg post on bat, and ground on chassis in front of car to neg post of bat.

[Shaggy]

I have a 90 L na wagon awd m/t. So I should add another ground to my starter other than the battery cable? I bought 15 feet of wire, also where is the intake manifold sensor. I looked on my car and in my Haynes manual and didn't find anything. Should I just ground it to the manifold where the plug wire holder is? Also, should I not do the strut tower grounds? Where do the stock strut tower grounds come from? Thanks for all ur help Josh, ur a subie genius bro.

I still haven't figured out the surge/ dashlight problem yet but I'm sure I will soon. It's buggin the crap outta me.

[Legacy777]

Those scans are good then for your car. These also may come in handy.
http://main.experiencetherave.com/subar ... agrams.zip

Some people go overboard with the extra ground leads. It's really up to you. I would suggest adding a second ground lead from the battery to the starter. The stock wiring can get old and could possibly have issues. The intake manifold, there is no sensor. There is a spot where the ECU grounds itself to the intake manifold. It is on the back side of the manifold on the driver's side. There is a bolt with a ring terminal going through it. Just add another ring terminal to that spot and run it to the negative lead on the battery. As I mentioned, if you want to add extra grounds, you can. That spot on the intake manifold is where the ECU grounds and is important for the sensors.

I really think you have a loose wire/nut somewhere, either on the power or ground side. You can redo these grounds, but you're going to have to dig into the wiring diagrams and do some testing. If you're not that savy with the electrical stuff, you may want to have someone help that is, or possibly take it to a mechanic to troubleshoot. The diagrams I posted should help in troubleshooting.

[Shaggy]

Thanks for the help Josh I realy appreciate it man.

[Shaggy]

I just replaced my battery cables a few days ago should I still run another ground from my starter?

[Legacy777]

If your battery cables are new, then no I probably wouldn't bother running another wire.

[Shaggy]

K that's wut I thought, I did the other grounds u said. I also checked the power wire that goes to the fuse box in the engine bay and still the same problem is happening. It isn't as bad tho now that I have done the grounds. I'm about ready to take it in and have it checked out.

[Shaggy]

Ok, so i know this is a few months old but i just bought a new alternator from napa cuz i havent been able to resolve this problem. After i installed it i look at the end of the connecter that plugs into the alternator and only 3 of the for holse had a little metal clip in it( i feel like an idiot). Im pretty sure that this is my problem. The alternator that i bought has a lifetime waranty for as long as i own the car so that im happy about, i'll never have to deal with having to buy another one and it was only $140. I havent driven it yet with the new alternator but im about to take it for a ride right now and see what happens. Would i be able to just get another connecter from like the junkyard or sumthin and just cut my connector off and wire the one i get to it or would that be a bad idea.

[Shaggy]

So i found out that its not supposed to have all four because there is only three wires that go to it. And no more flashing dash lights! It turns out it was my alternator all along. Sucks that i bought a junkyard alternator and it passed all the test at autozone and still ended being crap. It blew two sets of headlights, but they got replaced free of charge so thats good. Im stoked that its all good now. Thanks guys