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84 Brat Intermittently Grounding Out?


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I did some searching, but I didn't come up with much and electrical issues are my biggest weakness. So if I'm asking dumb questions, please enlighten me with your ingenuity.

 

The car: 1984 Brat with a replaced EA81. When the engine was replaced, some "extras" were removed and I definitely have some wires to nowhere.

 

The issue: Recently, when I turn the key to start the car, 1 of 2 things happen. It either:

      1.     Starts right up.

      OR

      2.     The dash lights up, the battery gauge needle hits about 8-10V and the starter doesn't turn.

 

If it starts and I drive it there are no issues. If I roll start it, jump it with the 50 amp setting on my batter charger, or jump it from another vehicle there are no issues running it and driving it. Once it is running the needle sits just above 12V and everything is great.

 

I got my battery tested. It is supposedly fine.

 

It seems that no matter what, if I drive the car then shut it off, it always starts back up if I try within a few minutes.

 

The questions: Is my starting circuit grounding somewhere intermittently and killing my battery? I'm assuming an intermittent short to ground because sometimes the battery is fine and other times it gets drained very quickly.

 

What should I look for?

 

Edit: I'm not sure if it matters, but the car had been mostly sitting for a year while I worked on it off and on to finish the lift and do some rust repairs to pass inspection. I just started driving it again last week and that is when the issue started.

 

Edited again for grammar.

Edited by jmoss5723
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How are your terminal connectors? I know I didn't tighten my + side up enough once and the dash would light up but it wouldn't start. I would check all the wires running to your battery and work back to see if there's an abrasion or loose connector somewhere first.

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How are your terminal connectors? I know I didn't tighten my + side up enough once and the dash would light up but it wouldn't start. I would check all the wires running to your battery and work back to see if there's an abrasion or loose connector somewhere first.

 

That seems like an easy enough place to start.

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Quite a few Japanese cars of this era end up needing a relay added to the starters circuit to take the load off the ignition switch - gives these sort of symptoms sometimes. Wire , single black from IGN to startr solenoid, pull off attach to 86 of a relay, 85 to earth. Fused 12V from battery pos goes to 30, then a fattish wire from 87 goes to the terminal you pulled single black wire off solenoid

 

Check the Fusible Links, under plastic cover follow pos lead from battery six inches, give intermittent crap at this age too

Edited by jono
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As Jono said, the resistance in the starter wire as it goes from the battery, through to the ignition switch, back to the engine bay to starter motor can get too much after time. It's even worse in automatics which take a detour via the gearstick...

 

The quickest way to check this is next time it won't start:

leave the ignition on (making sure the car is in neutral with the park brake on)

disconnect the small wire from the starter motor

connect another piece of wire rom where you pulled the small wire off the starter motor

touch this to the positive terminal of the battery & be ready to pull it off as soon as the engine starts

 

BE CAREFUL HOLDING THE WIRE AND MAKE SURE IT DOESN'T TOUCH THE CAR BODY, ENGINE, NEGATIVE BATTER Y TERMINAL, OR OUTER SHELL OF THE STATER MOTOR

 

If the egnine starts straight away with this, then I'd definitely install the relay like Jono said. Wouldn't hurt to do this anyway, it's only a small expense.

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One of the biggest problems I've seen as well is not enough, or faulty, grounds between the battery and chassis and motor to chassis. They go bad over time and should be upgraded. Personally I think the motor should be grounded on both heads instead of just one and I think the factory ground from the battery to the chassis is way too small. 

 

Does your car have any water damage on the inside? My 82 wagon did a similar thing before I got the windshield gasket replaced as it was leaking from the bottom corner passenger side and soaking the wires that run next to the heater blower. Its a good corner for mice too.

Edited by Hsoj
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Thanks everyone for the ideas. Certainly gives me some things to try.

 

I think I'll try Wagonist's test and if it works I will add Jono's relay, though I might need that broken down into a little bit more detail. As I said, electrical work is my biggest weakness, but I CAN follow instructions well. The "86 and 85" talk kinda went over my head.

 

I've already thought about cleaning up/beefing up my grounding points. Maybe now is the time just so that I can eliminate them as a source of the issue.

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85,86,87,87A, and 30  are standard terminal designation for bosch style 4 or 5 pin relays.

 

85 and 86 are the low amp "trigger" terminals.....basically a + and - to activate the relay. In this case would ground 85 and run the original starter wire to 86.

 

30 is the "in" for the High amp side......so in this case the battery power.

 

And finally 87 is the "out to load" of the high amp side. So in this case output to starter.

 

87A would be the "normally closed" position....not used in this case...

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85,86,87,87A, and 30  are standard terminal designation for bosch style 4 or 5 pin relays.

 

85 and 86 are the low amp "trigger" terminals.....basically a + and - to activate the relay. In this case would ground 85 and run the original starter wire to 86.

 

30 is the "in" for the High amp side......so in this case the battery power.

 

And finally 87 is the "out to load" of the high amp side. So in this case output to starter.

 

87A would be the "normally closed" position....not used in this case...

 

Thanks for the very clear breakdown. I can definitely work with that!

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  • 2 weeks later...

Quite a few Japanese cars of this era end up needing a relay added to the starters circuit to take the load off the ignition switch - gives these sort of symptoms sometimes. Wire , single black from IGN to startr solenoid, pull off attach to 86 of a relay, 85 to earth. Fused 12V from battery pos goes to 30, then a fattish wire from 87 goes to the terminal you pulled single black wire off solenoid

 

Check the Fusible Links, under plastic cover follow pos lead from battery six inches, give intermittent crap at this age too

Can you narrow down what size "fattish" is? I tested it and I'm pretty sure this relay is the solution. I just want to make sure I hook it up right.

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um? yeah ...not the major cables from the battery. The black wire, with white trace ? on it that is the only wire of its size that goes to the starter motor solenoid male spade terminal and is about 5mm across its total wire plus insulation. I'm not an auto elec and not conversant with gauge measures, can see the mm2 cross section when it is described, but think about it, ned a decent fattish wire to hold the solenoid in while starter is a cranking ....

Edited by jono
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Figured it out. basically I'm just setting up the relay so that the ignition activates the relay which sends power straight from the battery to start the car, instead of the power running through the whole ignition circuit to start the car. Right?

 

So I need a new fused 12v wire to power the relay. I'm hooking it all up today. I'll report back once its working.

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How many amps is this circuit calling for while engaged? I'm wondering how a typical 30 or 40 amp relay is going to handle the massive amount of cranking amps the battery is going to be sending through it.....

 

Quite well.Only the solenoid current goes thru the new relay.

 

Adding a extra part that could fail still seems like the wrong way to go,IMO.

Better to replace the ignition switch or replace/jumper the neutral safety switch as necessary.

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Naru;

 

I'm kind of leaning that way myself right now. I think I'm going to start with replacing the starter itself first with a remanned from Auto zone that I can get for free via warranty on one I replaced in my GL already. If that doesn't do the trick I'm going to look in to the ignition switch contacts and do a bit of searching on here about how to do that and where to attain the contacts. If THAT doesn't work then I'm probably going to just bypass everything with the relay trick in this thread.

 

/threadjack

Edited by l75eya
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I've only got a 20 amp relay and a 15 amp fuse. It all works well. It is cost effective.

 

My starter works fine and my ignition works fine, I just think the sum of the 30 year old parts and wiring can't deliver the power. Why throw a new starter at it if the starter works? (In your case the starter is free, but still.)

 

No matter what, I've learned that keeping a few feet of stout wire in the glove box is a good idea. I can always jump straight from the battery to the starter if something goes fubar!

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