Electrical Gremlin, different parts, erratic and changing. Lights,aircon,dashlights,immobiliser +

Troubleshooting
1

Hello all,

I have watched many of the youtube videos but now i need more assistance than is on any videos.

I have a 1991 GTO N/A Auto

maybe important for this issue, the car has a remote key fob, alarm and immobiliser all aftermarket as far as im aware they didnt come imported with any. I have a “CODEALARM” remote unlock buttons and a "TOAD fob hanging from my keys

So i have to start this off with my car has been working without problem’s for a few months. in December due to my other car having an issue this did all the holiday travel 3 x 4hr round trips and covered 800-1000 miles without skipping a beat not a single issue.

About 2 weeks ago the other car was sorted so i was using it again with the GTO sat around for a few days while we had that very cold frosty snap(-7 where i am) It was only moved on to the driveway to have a clean and then back to the road.

I went to go move it to the drive to tinker (check underside etc) few days later and this is were everything started from so…

Tried to open the car with the key fob not working i was a bit confused as i had just replaced the battery in it so i took it apart and clean the fob internals.

No luck so manually opened the door and there were no lights coming on so battery is dead bit random all of a sudden but i guess as it was cold not used.

So i got jump cables and jumped it and it sprang to life… with the addition of one snake eye (passenger) not coming on but weirder still the driver side snake eye, tail lights and fog lights refused to go out, with the stalk turned, button pressed nothing. on all the time even with no key with the constant ringing.

After i disconnected the battery got a battery charger and fully charged and put it back on the fog lights are still staying on but no ringing tail lights and snake eyes have gone off.

I think okay ill take it for a quick drive maybe it will sort itself out, handbrake/brake light ((O)) wont go out on dash and neither will abs(skidding car) or coolant carrousel. These were non issues before it died and coolant level is fine its never lost coolant, hand brake is fine.

So i go to take it out for another drive and now my heater/aircon unit isnt getting any power no screen no reaction from the buttons so i cant drive it or it will fog up and no way to defog the windscreen.

I disconnected the fog light relay left the car, next day went to unlock it and no luck so i assume battery is dead so put it on charge to which it says full… hmm.

Open the door and interior lights come om and barrel lights up but immobiliser leds are not flashing or on at all.

I put battery back charge/maintain last night car locked at the door with remote fob not working still (im sure my remote fob is tied to my immobiliser as i have to push unlocker before key will turn engine on)

My ring doorbell alerted me to a dog walker this morning and i could see a light on the car so i went to check and the passenger snake eye is staying on without any key in the car but driver side is off other lights are off.

Battery is now disconnected while i write this with the battery cables touching.

Fog light relay will be getting put back in to check.

All fuses have been checked, relays seem okay swapped around for different ones.

Does anyone have any ideas what is causing the most random, sporadic, erratic electrical gremlin i have.

Only thing i have found so far as a possibility is the ETACS unit?

Any help is greatly appreciated, As soon as the kids are at school ill be out there trying to get it working.

2

Still having the same issue car wont turn on anyone have any ideas?

3

Might be worth trying a different Etacs unit. I looked last year for one and there were a few on eBay for sale. Not too hard to swap over as its under the steering wheel dash area.

4

Yeah its fairly easy especially as i have the car completely stripped down. Just wanted someone to have an idea what might be causing it before buying stuff

5

@Joe90 sorry to tag you but you are the only gto specialist im aware of.

Everyone i ask is baffled by it and has no suggestions.

Any advice you can provide is greatly appreciated.

Currently

Car has power to interior lights, key barrel light, horn, hazards, hazard lights flash on dash, door open warning light on dash.

Stalks have no power, no pop ups, no climate control, key does nothing when turned no clicks, no pre start lights on dash with key turned to on or start.no window power.

12 v to 120a engine fuse, ignition switch fuse, power window fuse, battery fuse under bonnet, All fuses checked and fine under bonnet and dash.

1991 auto na jap import

6

You got me. I don’t see any common connection there. You will need a auto electrician to meter it though I’m afraid.

7

Thank you for taking the time to reply, guess ill just keep working through it.

9

The engine will not start if the dashboard is removed unless you remove all the electrical components from the dashboard and reconnect them in the car. You clearly have a serious short circuit somewhere that is going to take some investigation. Not everything needs to be connected but it will make it easier to fault find.

10

Oh, okay. i assumed anything on the dash wouldn’t be detrimental to the starting of the car/engine.

I am slowly digging through it, i have found some cables that have burned out insulation, but the main one is the handbrake switch cable, but why would that get so hot it’s melted?

I feel like im missing something because it doesn’t seem to make sense

Visally, my ecu and etacs look fine.

If anyone reading this is and based in the Midlands im in Kettering above Northampton, i would greatly welcome anyone to visit and attempt anything.

11

I have seen this cable burnt out before. It is where someone has had things apart and trapped an electrical cable when putting it back together. Over time, the shielding sleeve wears and a short circuit occurs. This is a common problem under the dash and centre console.

1 Like
12

So i have 2 different issues it seems

One being the power to internals maybe the handbrake cable was causing these issues?

Through the whole harness only thats yellow(black/green not sure) that has any damage.
I can see.

Im going to check through the cables one more time tomorrow but if no other visible issues ill be reinstalling the dash.

2nd issue is the car not starting everything on ignition system seems to be okay but i took my starter off today and it seems the starter solenoid battery positive connector/bolt is wobbling and im very sure this should be solid like the other one.

Fingers crossed a new starter/solenoid will get it turning on

14

So I rebuilt my car as I took dash out etc and hooked everything up.

I connected battery neg as the last step and my engine fans come on, so go inside the car my heater is working so turn it off, turn key dash lights come on very hesitantly and dim turn key they a go out lose power to everything.

I moved battery cables about and it come on again fans on, heater screen working, stereo on ,key get dash lights on then after trying to turn it on a few times all power went again.

Please if you need any more information please ask and I give as much information as possible.

I’m okay with cars electrics not so much.

Currently I have

Power to

Horn

Headlights via stalk

Pop ups

Interior lights

Key barrel light

12.5v bat pos

12.5v to battery,engine,ignition fuse under bonnet

Fog lights stay on even with key removed (fuse removed Currently)

Hazards work (flash on car and dash lights)

Door open warning light works

No power

Rest of dash lights

Indicators via stalk

Heater

Stereo

Turning key gives no dash lights

Separate tests my starter works fine with power to I checked solenoid and motor.

I have trawled through post after post on so many fourms and looked over the electrical diagrams etc so much.

It’s definitely my lack of electrical knowledge getting in the way but dont think I’m missing anything obvious.

Thanks in advance

If you want videos or pictures let me know they best way to send stuff for you to see.

So many pictures and videos to much to upload

15

Eletric is not my strong skill but it sounds like you got a short somewhere and personally i would’ve left the dash off untill the issue is resolved.
Hope you get it sorted

17

So the ABS unit bracket has a metal tab that was eating into my harness

1 Like
18

I belive that I mentioned this in my reply 8 days ago.

19

I think you said under the dash or center console and this was in driver side arch next to the abs pump.

Thank your help i appreciate it.

My srs light is on and my abs isnt working but the car turns on