1982 GL Brat--Rear Left--Turn Signal/Brake/Reverse Light Problem

[6 Star]

I did some searching and couldn't find much.
This problem really has me scratching my head.

 

1982 GL Brat

200K plus on the body

 

When the Left turn signal is on, it blinks normally as it should, however the "Stop Lamp" light will blink on the dash in time with the signal light.

 

When the Left turn signal is on, and the Brake is applied: The LR taillight alternates between turning on/off the Lamp and the Reverse light individually, and the time of the signal light on the dash is about half the speed. It completely forgets to flash the indicator light instead.

Having both Brake applied and turn signal on, the "Stop Lamp" light on the dash shuts off.

 

The right side is unaffected and has no problems with the signal under braking or not.

 

I have checked fuses, checked bulbs, and even swapped out the entire LR taillight assembly from another Brat; same result with the slow alternation of Brake light and Reverse light.

 

And just FYI the reverse lights work normally when in reverse.

 

Anybody out there have a similar problem? I'm thinking I have a bad ground or a short somewhere...

[TomRhere]

Sure sounds like a bad ground.

 

Pull the rear right hand panel, you'll find the connector for the rear harness, and the ground screw to the body of the BRAT.

 

My bet is corrosion in that connector for the rear harness. Have had that issue a few times on various BRATs.

[6 Star]

Thanks for the reply Tom, I did see a ground connected last time I had that right taillight off.

However I didn't check for corrosion, but the ground itself was not loose when I wiggled it.

I will have to check that out again and make sure the ground is solid.

[6 Star]

Update

 

 

I tested that ground for the Tail Light harness, under the right rear bed kick panel.

I disconnected it and cycled through the brakes and signals as before.
Having the ground disconnected changed nothing!

So I put a new connector on the end of the ground and put her back on...

Still no change.

 

 

Then I noticed a relay dangling down from above the fuse box in the cab.

There are two identical looking round, two prong relays in these Brats, according to the Haynes '80-'88 Workshop Manual, Fig. 10.40 1982/1983 North American models.
The one on the left is the Hazard Unit, BLK/WHT & GRN/YLW with Pink Connector

The one on the right is the Turn Signal Unit, GRN/WHT & BLU/WHT with White Connector

The one hanging down I noticed is the right, Turn Signal relay.

 

 

I unplugged this turn signal relay, and then cycled through the brakes and lights again.
Having the Turn Signal relay disconnected changed nothing! Haha!

I then pilfered another Signal relay from another Brat I have, and plugged that in.

As soon as the connection is made, the relays start clicking, as if I had the turn signals on, which I did not, the ignition was also in the full off position. Not only that, but I hear the fuel pump cycling in unison with the turn relays!

Neither the turn arrows on the dash or signals are blinking with this rhythm, they just stay off.

 

At this point, I had to start the Brat so that I wouldn't flood the carb and drain the battery.
With this new relay and paranormal activity happening, I tested the signals and brakes again.

I turned on the Hazards, and they flashed as normal except that the "Stop Lamp" light flashed with them.

Turned on the Left and Right signals one at a time, they both stayed on solid instead of flashing, and the left signal still had the "Stop Lamp" buddy along with him solid.

 

I then tried the brakes and signals, the right signal would just stay solid as before with the brakes lit up as well.

The left signal with the brakes would light up the reverse and brake light solid, and not the rear signal.

The hazards with the brakes would cycle the brake and reverse light on the rear left side and the signals on all other corners.

 

Another thing I realized that I never noticed on the initial tests:
When the reverse light is being flashed in alternation with the left brake light as a turn signal; both reverse lights flash! I only ever noticed the left side alternating, and not the right side reverse light flashing along with it. Haha

 

 

So it seems I must dig... a little deeper.

[TomRhere]

With this latest description of lighting weirdness, it definitely points to a ground circuit issue. Most likely in the rear wiring harness itself, but could be in either light housing. You changed out one with no cure, may be the other housing causing it, can't say..

 

I say that because automotive wiring will do some strange things when a circuit looses it's ground. It will seek ground thru another circuit's wiring, especially with lighting circuits.

 

Ever been behind another vehicle what has both tail lights working until the driver hits the brakes, one tail light goes out and brake light comes on on the opposite side. Or, they have one tail light, one brake light lit until the brakes are applied, and things just don't look right to you.

That is due to poor ground circuit in the harness and/or light housing.

 

Can be a frustrating job to fix. Been down that road a few times.

 

As I posted before, there is a connector behind that panel that feeds everything on the rear, tail-license lamps, brake/turn lamps, fuel gauge/low fuel lamp..

Take a good look at it, lightly tug on each wire on both halves.

You are looking for corrosion, or a broken wire.

[TomRhere]

More thoughts....

 

The wiring harness from the Left Light housing runs down thru the body, then goes thru a grommet and comes out underneath to run across to the Right side.

The License plate lights tie into the harness as it runs across the frame rail, as does the leads for the fuel sender.

Harness passes thru another grommet and comes up to where the Right Light housing plugs in, then goes forward to the connection behind the Right rear panel of the bed.

 

Possible corrosion issue where the License lights ground wires tie into the harness, or where the Right Light ties in.

Maybe even some chaffing of the harness where it passes thru those grommets.

[TIMBERTIGER]

I know this thread is from waaaaaaay back in 2017 but did this issue ever get resolved?

[6 Star]

Unfortunately no, @TIMBERTIGER, I never got around to fixing this issue...

This '82 Brat is my "work" Brat. It will occasionally haul stuff to the dump, load firewood around, etc... the coolest side-by-side atv / power wheelbarrow one could ask for.

I found it in pretty sorry condition in the woods of South Puget Sound. It was missing the carburetor and had been sitting many years collecting moss. Flushed the fuel system and installed a new Weber, and she was in business. All I have had to replace since then has been a clutch cable. I've never had to touch the braking system even...

Following that trend of seat-of-the-pants driving excitement; I've been purposely not fixing anything that wasn't keeping the Brat from driving. Subarus really are inexpensive and meant to stay that way. Since the condition of this Brat isn't stellar, I have better condition Brats, and I also wasn't sure if this Brat would turn into a parts car; that also postponed the fixing of the issue.

However I still need to put the Tailgate on this Brat. Maybe I'll try and sort this issue at the same time. Heck maybe I'll restore the whole Brat the way prices are going...

Edited December 22, 2021 by 6 Star

[TIMBERTIGER]

I appreciate your reply 6 star.  I ended up selling the car without finding a solution. I hope you are able to figure yours out eventually.  Let us all know if you do!