Electrical problem 1984 D88: Turn signals light up when breaking?

1984_Delta88

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Apr 17, 2019
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Hi there!

My 1984 Delta88 came with factory amber turn signal and separated break lights.

Like this: (pic from barnfind.com)



Currently I have the problem that my rear turn signals light up together with my break lights when breaking. I did not really change anything and I am 100% sure this wasn’t like this before. I assume there is might be a problem with the blinker switch? Or is the signal wired through the break light switch? Or a bad grounding?
I did quick measurements. Tail light seems to be OK as I can measure the “breaking current” directly at the turning light cables at the connector in the trunk (with no lights connected).

From my understanding this behavior is typical for all red tail lights. But none of my repair manuals shows the “amber turn signal” wiring. And I can confirm they did not light up before when breaking.


So my question:

- Does anybody know the wiring for amber turn signals?

- Anybody ever experienced a similar problem?

- Where can I find the blinker cables (light green and yellow guess) at the blinker switch? Steering wheel column? Steering wheel contact ring? Somewhere else?


delta-1-e1542698750271-630x390.jpg
 
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GoodOldsGuy

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Oct 20, 2020
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Like CapriceChris said, the flasher relays are a good place to start.

Is the car equipped with a trailer light connection? If so, make sure that wiring has not been damaged/crushed/pinched or otherwise adversely molested.

Just out of curiosity, do the front turn signals light up when you step on the brake? And do the rear brake lights come on with the turn signals? Both sides at once?

When you said you hadn’t “really” changed anything, does that mean that you REALLY didn’t change anything, and haven’t touched anything in that circuitry at all? I’m asking because if it wasn’t like that before, SOMETHING has changed, and it’s easiest and best, to double check the things that did get touched and verify that they are not the “something” that changed in the system and caused this issue.

Make sure that the correct light bulbs are correctly installed in the correct sockets, and that there is no corrosion on the bulbs and sockets. The wrong bulb in the right socket can do some crazy stuff. and could be the cause of this kind of sorcery. I’m not sure, but I believe that your car uses multifilament bulbs in the brake lights and turn signals (front and rear) that allow the lenses to be parking/tail lights in addition to brake lights and turn signals. Incorrect installation or installing a single filament bulb where a multifilament should be (and vice versa) could cause those circuits to cross and react to each other. Any bulb that is not crystal clear (or clear amber if that’s the case) should be suspect. Any bulb that has “smoke” build up on the inside of the glass, or especially any bulb that appears to have a chrome finish on the inside of the glass should be replaced.

Lastly, your turn signal switch is inside the steering column directly underneath the steering wheel lock plate and spring. Your turn signal lever attaches directly to the switch. That turn signal switch also incorporates your 4 way hazard light switch , and cornering light switch. Even though your turn signal lever operates your high beams, that is usually a different switch that is under the turn signal switch. The turn signal switch has a large connector on the left side of the bottom of the steering column. (Left from the drivers perspective). If you’ve never replaced one, read up on it well, and consider getting some experienced help. All that said, It is very unlikely that your problem is coming from the turn signal switch. If it feels right mechanically, I’d save that for last and rule out everything else before I started looking at that switch.
The cause of this sort problem is most often something relatively simple, so start with those things. Bulbs, flashers, the last thing that was worked on, etc.
Good luck, and God speed :)
 
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1984_Delta88

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Apr 17, 2019
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Like CapriceChris said, the flasher relays are a good place to start.

I will do anyway. Generally I do not like just to change parts without knowing if it is defect. So I will test them after disassembling.

Biggest thing is... how the heck does the signal from my break switch get into the turn signals? As I said, lamps are completely disconnected and I am measuring at the connector in the trunk.

With the pre 84 it is clear, that the turn signal is routed over the bereak light switch. But for my 84 with amber turning signals I do not see a connection at the break light switch itself. Without understanding the wiring it will be tough. I guess I need to rip apart the interiour and do some deeper analysis of the cable routing myself :D I did a qucik search (lying in my car upside down with my feet sticking out of the driver side window :-/ ) but it seems the yellow and green cable ar directly connected to the switch behing the steering wheel column.

index.jpg
All bulbs checked.

vlcsnap-2021-07-19-21h48m38s482.png

This is how it looks when I push the break pedal. If I break and switch turn signal on one of the amber lights starts flashing.

vlcsnap-2021-07-19-21h51m17s356.png

Front lights work normal



Is the car equipped with a trailer light connection? If so, make sure that wiring has not been damaged/crushed/pinched or otherwise adversely molested.

No, nothing like this...

Just out of curiosity, do the front turn signals light up when you step on the brake? And do the rear brake lights come on with the turn signals? Both sides at once?

When you said you hadn’t “really” changed anything, does that mean that you REALLY didn’t change anything, and haven’t touched anything in that circuitry at all? I’m asking because if it wasn’t like that before, SOMETHING has changed, and it’s easiest and best, to double check the things that did get touched and verify that they are not the “something” that changed in the system and caused this issue.

Very good hint! Yes, you are right. I did change the water pump and... tha alternator :-o. Alternator at least could have something to do with it. Maybe... but it was a plug and play job and the part was even same brand (ACDelco vs. same part No. ACDelco).

Thing is, I do not know when it started exactly. I only check my break lights from time to time... and some months ago it worked well, I even have a video of it.

20191006_131603.jpg


And then all out of the sudden it started being wierd...

Make sure that the correct light bulbs are correctly installed in the correct sockets, and that there is no corrosion on the bulbs and sockets. The wrong bulb in the right socket can do some crazy stuff. and could be the cause of this kind of sorcery. I’m not sure, but I believe that your car uses multifilament bulbs in the brake lights and turn signals (front and rear) that allow the lenses to be parking/tail lights in addition to brake lights and turn signals. Incorrect installation or installing a single filament bulb where a multifilament should be (and vice versa) could cause those circuits to cross and react to each other. Any bulb that is not crystal clear (or clear amber if that’s the case) should be suspect. Any bulb that has “smoke” build up on the inside of the glass, or especially any bulb that appears to have a chrome finish on the inside of the glass should be replaced.

On my model turn signals are single filament and connector also only has two wires (hot and ground).

All bulbs worked as they should earlier. I just went out and checked every light again. All good.

Lastly, your turn signal switch is inside the steering column directly underneath the steering wheel lock plate and spring. Your turn signal lever attaches directly to the switch. That turn signal switch also incorporates your 4 way hazard light switch , and cornering light switch. Even though your turn signal lever operates your high beams, that is usually a different switch that is under the turn signal switch. The turn signal switch has a large connector on the left side of the bottom of the steering column. (Left from the drivers perspective). If you’ve never replaced one, read up on it well, and consider getting some experienced help. All that said, It is very unlikely that your problem is coming from the turn signal switch. If it feels right mechanically, I’d save that for last and rule out everything else before I started looking at that switch.
The cause of this sort problem is most often something relatively simple, so start with those things. Bulbs, flashers, the last thing that was worked on, etc.
Good luck, and God speed :)

Thanks so much. Really appreciate your help. I will keep you posted on the progress. Switch seems to feel right. Would I need to pull the steering wheel?

Check to see if your hazard light switch is stuck on. I would change both flashers due to age.
Hazard switch is OK and works well.
 

1984_Delta88

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Apr 17, 2019
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Oh, and this is the connector in the trunk. I could measure 12V on break light and on both turn signal contacts.
20210719_213108.jpg
 

GoodOldsGuy

Member
Oct 20, 2020
41
8
Texas
Your
I will do anyway. Generally I do not like just to change parts without knowing if it is defect. So I will test them after disassembling.

Biggest thing is... how the heck does the signal from my break switch get into the turn signals? As I said, lamps are completely disconnected and I am measuring at the connector in the trunk.

With the pre 84 it is clear, that the turn signal is routed over the bereak light switch. But for my 84 with amber turning signals I do not see a connection at the break light switch itself. Without understanding the wiring it will be tough. I guess I need to rip apart the interiour and do some deeper analysis of the cable routing myself :D I did a qucik search (lying in my car upside down with my feet sticking out of the driver side window :-/ ) but it seems the yellow and green cable ar directly connected to the switch behing the steering wheel column.

View attachment 254
All bulbs checked.

View attachment 256
This is how it looks when I push the break pedal. If I break and switch turn signal on one of the amber lights starts flashing.

View attachment 257
Front lights work normal





No, nothing like this...



Very good hint! Yes, you are right. I did change the water pump and... tha alternator :-o. Alternator at least could have something to do with it. Maybe... but it was a plug and play job and the part was even same brand (ACDelco vs. same part No. ACDelco).

Thing is, I do not know when it started exactly. I only check my break lights from time to time... and some months ago it worked well, I even have a video of it.

View attachment 255

And then all out of the sudden it started being wierd...



On my model turn signals are single filament and connector also only has two wires (hot and ground).

All bulbs worked as they should earlier. I just went out and checked every light again. All good.



Thanks so much. Really appreciate your help. I will keep you posted on the progress. Switch seems to feel right. Would I need to pull the steering wheel?


Hazard switch is OK and works well.
Your turn signal switch and hazard 4 way switch are combined into one switch, and yes, it’s under the steering wheel which has to be removed to access the switch. It has a long pigtail that goes through the steering column to a connection to the rest of the harness, on the left side near the bottom of the steering column, above the brake pedal. But again, it is extremely unlikely that that switch is causing your problem if the turn signal and 4 way feels and functions normally. The connection for that switch is near the bottom of the column. I strongly recommend leaving that switch alone, especially if you’ve never changed one before. It is many multitudes more difficult to replace than a flasher relay.

The last picture in this series is a view from behind with what appears to be the left turn signal on. This is how it functioned before, correct? The left brake light (the red) is clearly on at the same time as the left turn signal lamp (the amber). Is that normal? Does the red stop flashing when you step on the brake? Does the amber stop flashing when you step on the brake? I’m asking all this because if the turn signal can light up a brake lamp, then a brake lamp can light up a turn signal-unless something prevents it from doing so. Now, if the red and amber working in tandem is not normal, then some thing has changed. The wiring is static, it’s not moving around and is not considered a normal wear item. So if the wiring has not been molested (spliced into, damaged from a wreck) it is extremely unlikely that the wire insulation has failed on the exact 2 wires only, in exactly the right place for those circuits to cross and NOT blow fuses and/or burn up other stuff. It’s possible, but I don’t spend a lot of time looking at the sky to avoid being struck by a meteor either. The normal wear items in the system are the bulbs, then relays, and lastly the switches. The common denominator between the turn signal and brake lights (and can usually override the function of one or both of them) is the turn signal/hazard flasher relay. (You may have one that operates both, or 2 separate flasher relays). I’m confident that electromagnetic mechanical flasher relays were the norm in 1984 (not solid state magic boxes), and since that’s the only moving part in the system that is not your turn signal switch (that you say feels right and functions correctly), it should be high on your list of likely culprits.

If something fails out of the blue, on its own, 99.9% of the time it’s a normal wear item or mechanical item failure, in this case, light bulbs/corrosion or electromagnetic relays.
 
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1984_Delta88

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OK, just got the flasher relay and exchanged it today. Nothing changed... I keep on searching.
 

markclark

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May 2, 2021
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Attached are files from the factory service manual. Your Red brake lights are to be completely independent of the Amber turn signal wiring scheme.

Check to see that the White wire to the right of the Turn Signal Hazard Warning switch was not inadvertently connected to the fuse by someone in the past. That is the only way to connect brake lights and flashers on your car - unless somebody did a hack wiring job in the past - such as running jumpers between the brake and turn signal lights.

Get a test light and isolate the circuit parts until you find the improper connection.
 

Attachments

  • SERVICE MANUAL 1984 DELTA 88 TURN SIGNAL OPERATION.pdf
    976.9 KB · Views: 42
  • 1984 DELTA 88 W AMBER TURN SIGNALS.pdf
    252.2 KB · Views: 45
  • 1984 DELTA 88 W RED TURN SIGNALS.pdf
    254 KB · Views: 47
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1984_Delta88

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Apr 17, 2019
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Attached are files from the factory service manual. Your Red brake lights are to be completely independent of the Amber turn signal wiring scheme.

Check to see that the White wire to the right of the Turn Signal Hazard Warning switch was not inadvertently connected to the fuse by someone in the past. That is the only way to connect brake lights and flashers on your car - unless somebody did a hack wiring job in the past - such as running jumpers between the brake and turn signal lights.

Get a test light and isolate the circuit parts until you find the improper connection.
Wow, thanks! This is awesome and will help a lot! Hope I find some time at the weekend to double check al the connections again.
 

blkop

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Aug 2, 2021
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Hello you are dealing with a very frustrating yet common problem
i worked at and oldsmobile dealer years ago during the eighties and this was a very common problem with delta 88 models with seperate amber turn signals did you have this car as new or was it something you aquired i doubt the turn signal switch assembly in the column was "messed with" and it is highly unlikely the turn signal flashers are at fault does this vehicle have factory cruise 83 had cruise with resume 84 started cruise with resume and accel
more than likely your stop light switches are at fault there are two mounted upwards of the brake pedal hope this helps and feel free to contact me if you want you can change your turn and hazard flashers to # 262 electronic more precise and has that " click " 100% improvement over the thermal ones that came with the car by the way sweet car you have they do not make them like that anymore!!
 
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1984_Delta88

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Apr 17, 2019
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Hello you are dealing with a very frustrating yet common problem
i worked at and oldsmobile dealer years ago during the eighties and this was a very common problem with delta 88 models with seperate amber turn signals did you have this car as new or was it something you aquired i doubt the turn signal switch assembly in the column was "messed with" and it is highly unlikely the turn signal flashers are at fault does this vehicle have factory cruise 83 had cruise with resume 84 started cruise with resume and accel
more than likely your stop light switches are at fault there are two mounted upwards of the brake pedal hope this helps and feel free to contact me if you want you can change your turn and hazard flashers to # 262 electronic more precise and has that " click " 100% improvement over the thermal ones that came with the car by the way sweet car you have they do not make them like that anymore!!

OK, thanks so much. Actually, I went through the cables with help of the wiring diagram and could not find anything suspicious. So I kinda decided to cross out another option and already ordered a stop light switch at Rockauto. 😁

But apparently last week was a really bad one for me :( On the way to work my heater hose blew up :-o Luckily I was able to stop immediately. Hose definitely felt soft and chewy. Looks like it has been sitting there for ages (maybe for almost 40 years 🙈) . So I threw in some new hoses, filled up some coolant and everything worked fine again 😀
Until one week later I suddenly lost 1st gear :oops: Transmission is leaking fluid badly. But fluid level still was in an OK range the moment it happened with engine running. Was the first thing I checked. Will get it on a hoist and open the transmission to see if it is toast...



My 88 came with factory CC. Switching turn and hazard flashers sounds interesting, but as the car is no longer in the states it would make things complicated 😉 I imported it several years ago from New York to Germany.
 

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