Vasi

Hey all,

Possible relevent background:

'93 hatch with unknown mileage D15B swap from a previous owner, aftermarket alarm, what I believe to be aftermarket power locks due to the hacked installation look. Brutally messy MSD box install. In the process of figuring out how to revert it to stock.

Door alarm would sound randomly, so I stopped arming it. The car sometimes thinks one door is open.

My brake lights stayed on last night. Disconnected the battery overnight. Investigated the rubber stop thing, and it's still there. No problem after reconnecting battery. Slight burning smell in cabin that I can't trace. No relays I can find feel too hot to the touch.

The Problem:

Car runs sometimes after turning key off. Sometimes there isn't a problem, but when it runs on, it's usually for a few seconds until it dies out. This morning I had to kill it with the clutch. The oil and battery lights that come on when the key is in the 'run' position sometimes stay on with the key out, but are dim and flicker like there is a weak connection. Sometimes the clock illuminates as well. The climate control and radio properly turn off and stay off when this occurs.

I've found a few references to the ignition switch test, but I have no idea where the 7-pin connector is. The 5-pin is easy enough. I opened up the ignition switch to look inside. It seems pretty straight-forward. I'm not sure how it could fail in this scenario unless the rotating assembly keyway is worn and doesn't actually rotate it off the battery connection, but that doesn't seem to be the case from what I saw.

Is it possible that there's a bad ground in the aftermarket alarm/lock system that's dumping power from the battery to the key-on ignition system after the cylinder? If that's the case, would the ignition switch test be compromised?

I'm not an electrical person by any means, so I could use help. Can anybody offer some insight/advice, and also tell me where to find the 7-pin connector so I can test the ignition switch?

Vasi

Update:

Completely removed the aftermarket alarm/central locking system. Didn't fix anything. The first time the brake lights stayed on, they came back off after reconnecting the battery. They now stay on permanently. Depressing the brake pedal illuminates the brake lights slightly more than what they're doing otherwise, which leads me to believe it isn't the sensor. I want to try disconnecting the sensor to see if it'll kill the lights or not, but I can't seem to get my clumsy hands up there.

Did I read the electrical diagrams correctly, that the brake sensor goes through the ECU?

I found the 7-pin connecter (it's above the fuse box, right? It's part of the ignition switch wires?). I don't have a multimeter with me, so I unplugged the 7-pin and 5-pin connecters and reconnected the battery. The brake lights still come on, the oil/batt lights still come on, and I can still hear the fuel pump priming. Does this rule out the ignition switch?

What should I be looking for? It happened on it's own, and not as a direct/immediate result of tampering with anything. I'm thinking fused relay, or a bad ground causing the power to ground completely through other systems. But again, I'm not an electronics guy.

Any thoughts?

Former User

Get a multimeter. You need one to help you pinpoint the problems.

Do the brakes lights or taillights/parking lights stay on?

If you remove 20A hood fuse 42, do the "brake lights" turn off?

Post pictures of the wire sides of what you think are the 5P and 7P connectors. They can be identified by having the correct wire colors at the correct locations.

Vasi

Thanks Ron,

20A "STOP" fuse removed:


So, I pulled the fuse and hooked up the battery, and I didn't hear the fuel pump prime. Went inside, and the dash lights associated with key on/engine off weren't illuminated. Car started fine, ran fine. Went behind the car (with 20A "stop" fuse pulled):



The high mount doesn't come on with the running lights, does it?

Engine stopped when I turned the key off, I didn't have to kill it with the clutch. I put the 20A back in, and the dash lights came back. High-five for progress.

My idea of 5-pin:



And 7-pin?

Former User

Was there any change in the rear lights that stay on with the brake light fuse removed? Does the high mount brake light illuminate when you press the brake pedal (with or without brake light fuse installed)?

Your pictures proved beyond a shadow of a doubt that you found the correct 5P and 7P connectors.

Looks like the previous owner did some overly creative rewiring to install the alarm system and central locks.

Vasi

With the fuse pulled and the car off, the brake lights stay off. Depressing the pedal doesn't illuminate them now. Turn the car on, still with fuse pulled, the brake lights come on and stay on. Depressing the pedal doesn't illuminate them further as it does with the fuse in. Turn the car off, and the brake lights turn back off. Put the fuse in, and the brake lights come back on.

Former User

Does the high mount brake light illuminate in this case^?


Does the high mount brake light illuminate in this case^?

Vasi

Yes, high mount is illuminated in all cases.

Former User

Why is this^ significant?

With fuse 42 removed, none of the cluster warning lights (CEL, SRS, low oil pressure, seat belt) illuminates, even the charging system light?

Former User

With fuse 42 removed, do the brake lights also turn on with the key in ON(I) or just ON(II) (engine off)?

Vasi

Because the fuel pump would prime when I connected the battery lately, probably due to the short that keeps the engine running indefinitely.

Only before key on. These lights would illuminate once the battery was connected. Now with the fuse pulled, they don't stay on all the time. They work properly with the key turned to run, and go off properly when the engine starts. I apologize for the confusion.

I'm looking at the diagrams, and the 20A brake fuse goes off to the ECU and the cruise control module after the brake light switch, as well as connects to #15 10A under-dash fuse, which connects to a lot of dash components. I disconnected the module, and no change.

Disconnected the ECU, just for kicks, and also no change.

I see what you mean about a multimeter.

Vasi

Only ON(II) engine off, not ON(I).

Former User

Is this problem now gone? Or only gone when fuse 42 is pulled? Did the fuel pump prime for just 2 seconds or run continuously?

Remove both fuse 42 and 10A fuse 15. When you turn the key to ON(II), do the brake lights and the cluster warning lights now NOT turn on ever?

Where did you find that fuse 42 and 15 are connected?

Former User

Good.

Vasi

Only gone when fuse 42 is pulled.

In ON(II) with fuse 42 and 10A fuse 15 pulled, cluster warning lights and brake lights remain off. Charge light stays.


Poor choice of words on my part. On page 23-254 of the service manual, it shows that the cruise control module connects to #42 20A, and separately to ignition sources #15 10A and #12 15A.

Former User

With fuse 42 installed, does the fuel pump prime for just 2 seconds or run continuously when the battery is connected?

Excellent

Correct, but the circuits themselves are not normally connected.

Vasi

It seems to be holding for closer to three seconds, but definitely not continuously.

Not normally, but there is the burning smell I mentioned in my first post. It's possible something melted in the module and shorted the two. Clearly now it didn't, but I just wanted to rule something out.

Former User

Good.



Are the Wht/Grn and Blk/Yel wires in the cruise control unit connector cut and spliced together or melted together?

Former User

Where is the burning smell coming from? Can you locate it?

It's also time to unplug the brake light switch at the top of the brake pedal. Does unplugging it make the brake lights turn off when fuse 42 is installed and the key is off? Any of the wires in the 4P connector melted or spliced together?

Vasi

Not that I can tell. I'm having a hard time accessing the bolts above the cruise control unit to remove it and the bracket to inspect that whole section of harness.

The aftermarket alarm/central locking was spliced into the ignition harness between the fuse box and the ignition switch, and the rear lights after the C414/415/416 rear harness connecters (I'm not sure which one the wire belongs to, but that area).

I found something at the top of the harness where I can barely get my fingers. It looks like it's right after it comes through the firewall. The Grn/Red and Grn/Wht wires are taped together with blue tape of some kind. Based on the inaccessibility of the location, I'd hope it was factory. Still, strange.




I'm going to wait until my fingers thaw, then try looking again.

Vasi

I haven't been able to trace the burning smell yet, but it's definitely coming from the driver's side wiring nest. I'll see if I can scratch enough material off my hands to reach that brake switch connector. Wish me luck.

Former User

Here are my preliminary conclusions:

1) The brake light switch is stuck on or the switch brake light wires are jumped to bypass the switch. This is the reason the brakes lights remain on with the key off.

2) Somewhere, likely under the driver side dash, the Wht/Grn wire for the brake lights, the Yel wire for the cluster gauges and warning lights, and the Blk/Yel wire for the main relay are probably either spliced together or melted together. This triple wire fusion allows fuse 42 for the brake lights to supply voltage to the Yel wire of the cluster and to the Blk/Yel wire of the main relay without the key on. Conversely, it also allows fuse 15 and fuse 24 to supply voltage to the brake lights when fuse 42 is removed and the key is on.

Fixing the brake switch issue and locating/repairing the triple wire fusion should solve the problems.

Vasi

I managed to unplug the brake light switch. Lights remain on with fuse 42 in place and the key in my pocket.

The Blk/Yel naming convention is Solid/Stripe, correct?

I would think a fuse would pop before a wire would melt, but I've been wrong before. The fuse box was also unsupported, along with many relays, so there's a large possibility for chaffing the insulation away. I'll just have to sniff my way toward that burning smell.

Thanks for all your help today. You're a gentleman and a scholar.

Former User

Your test result tells you that the brake switch has been bypassed, allowing the Wht/Gn wire to supply constant voltage to the brake lights. The previous owner may have intentionally spliced the Wht/Grn wires together upstream and downstream of the switch or some damage has occurred that unintentionally caused the splice. Where this bypass has occurred may be the same location whether the Yel and the Blk/Yel wires splice into the Wht/Grn wire.

Leaving the switch unplugged, now remove fuse 42 and then turn the key on. Do the brake lights still turn on? If so, does removing either fuse 15 or 24 or both cause the brake lights to turn off?

Correct

Only if there is a short to ground, which currently does not appear to be the case.

Definitely worth pursuing.

Former User

Hmmm...are you sure about both^ test results? They seem at odds with one another. I can't understand how fuse 42 (brake lights) could power the main relay/fuel pump if fuse 24 (main relay/fuel pump) could not conversely power the brake lights.