cfair

I’ve got a ‘66 98 which suddenly today exhibited some really weird behavior when activating the left turn signal. This car has a tilt&tele column which grounds the turn signal switch, no turning lights, and has run 2357 (brake/turn) and 2357A (amber fronts) for years. The bulbs are higher wattage than stock, so they create more heat, but have worked well for 3 - 5 years.

The harness was replaced / modified 10 years ago or so to accommodate an internally regulated alternator and HEI. Just so you know it’s not quite stock. The fairly complex ‘66 98 taillights were dodgy for years until I rebuilt the tailllight harness with thick, fresh wires. Pretty sure I have the rear harness right since it’s worked well for years.

Suddenly today the turn signal switch didn’t work correctly at all. The flasher relay didn’t flash, so I just did hand signals ‘til I got home. Plus the left rear brake light was dim relative to the right brake light. I have a reproduction turn signal switch, and cleaned it, but it’s working fine and that made no difference. Hoping for a dead flasher relay, I tested 2 alternate (not new) flasher relays, but the wires into the turn signal switch still got very hot no matter which flasher relay I use.

The main thing that’s dangerous is when invoking the left turn signal, the switch wires get hot really quickly. Approaching melting hot. Right turns don’t create the same heat problem.

So I thought, probably rear bulbs or the rear harness. But nope, they’re fine. Admittedly, the rear bulbs have a high voltage draw as 2357 instead of stock 1157, but it’s worked well for years.

Suspecting a rear, or mid-body harness short, I disconnected the ribbon cable to the rear, and activated the right turn switch. The switch wires when left turn was activated still got real hot. So it seems like the problem is forward of the rear bulb harnesses.

I learned tonight that if you don’t have the turn signal switch connected, the brake light switch gets no power. So now I sort of have an electrical signal path: I think it’s Fuse Block to Turn Signal Switch to Brake light switch.

I thought tomorrow I’ll try stock wattage bulbs just to see if the overall draw is low enough to not cause heat problems. After that I’m about empty unless I go after replacing the whole harness. Which is bazooka-to-kill-a-fly approach to me.

Somewhere in the middle is pulling the dash, stripping the harness and finding the short, but I’m hoping there’s an easier way.

Do any of you have suggestions about how to trace out this short? Many thanks in advance.

Cheers
Chris

Sugar Bear

If it was bulb related it should share the problems on left or right turn. I'm thinking there is a short between the disconnect of the ribbon and the turn signal switch. Using a test light or VOM check the wires for a short between each other or to ground. Move the column around while checking.

Good luck!!!

cfair

Turned out to be multiple failed old-style flasher units. I swapped in the newer style digital flasher unit from Napa and it worked just fine.

I was afraid it wouldn't click, but it does that too.

Now I just have to get one for the busted flasher on the Flarestat hazard light system, but at least I'm back on the road with turn signals.

Cheers
cf

cfair

Turned out I was wrong. The digital flasher is masking the problem, but it’s still there. When I hit the left turn signal, the wires heat up within about 6 blinks. When I hit right turn, no heat problem.

Weird.

If I have it right when you put the turn signal in the left turn position, there are 3 outputs: front turn light, rear turn light and the speedo indicator light. I’d think that by disconnecting each one in turn, I’d find the short. Well, not so far…

I disconnected the speedo head in case the indicator light was the problem. Same over heating problem.
I disconnected the rear ribbon cable which carries the signal to the tail lights. Same over heating problem.
I tried a different thoroughly cleaned AC/Delco turn signal switch, same overheating problem.

Tomorrow I’ll try disconnecting the front turn signal and see where that gets me, but I feel like the problem is on the inbound power line to the turn signal switch. The line from the flasher to the switch gets hot when hitting a left turn, indicating that something downstream is pulling too many amps.

The inline Flarestat flasher wires got so hot they melted slightly, so they’re out of the circuit until I can repair them. Easy to disconnect. At the time the flasher for that system was removed, perhaps that was a mistake.

It seems that the turn signals are fed power from the accessory circuit on the ignition key switch. I think it’s getting to be time to see if I’ve overloaded and melted something upstream of the turn signal switch. One move for tomorrow is to pull the keyswitch connector and look for a melt or overheating condition. I’ve seen these in lots of Olds. If it’s there I can fix it.

Today the stereo head unit lost it’s unswitched fused battery power for a few minutes too. It’s hooked to the circuit breaker, so I’m guessing I tripped that somehow. Do 40 amp circuit breakers get old and eventually fail? Wondering if there are multiple problems.

It’s beginning to feel like time to pull the dash and repair or replace the harness. That’s a pretty big project, but not unknown or unwelcome to me. Just hadn’t banked on it for September…

Suggestions welcome.

Chris

cfair

Update: turn signals ran fine this morning with a cold car. O.k., so maybe I have too many aftermarket accessories pulling amps through the ignition switch accessory circuit.

Each project was sequential and I suspect I just have too many patches on the Olds electrical harness quilt. Time for a revamp with an actual design instead of organic growth.

I’m working my way toward the conclusion that I should leave Olds accessories like power windows, power seat, cruise, and power antenna on the fuse block accessory circuit, then run a low amperage accessory-switched line to a relay which powers up the aftermarket switched circuits for stuff like Alpine Stereo, Innovate 02 sensors, digital tach, and USB outlet.

Do any of you have recommendations about what relay to use? My initial thought is 40 amp, powered up by the ignition accessory circuit, but I’m open.

jcdynamic88

if you have the accessory 4 way flashers under the dash i would suspect that unit,i've had to eliminate that on two of my olds in the past due to turn signals not working or intermittently working

cfair

Thanks for your thoughts. I’ve had these units for years and never had a problem until now. But times do change.

I took my Flarestat hazard flashers out of the mix first thing and tested the turn signal system. The problem was still there.

After hooking it back in, a couple of the hazard flasher wires got melty-hot so it is disconnected now. Yesterday the signals worked correctly before I fired up any accessories.

I’ve got a fair few switched accessories pulling amperage on the keyswitch accessory circuit - aftermarket radio, oxygen sensors, digital tach and a USB port.

I suspect that on top of factory cruise, power windows/seat, power antenna from Oldsmobile, I’m overloading the ACC circuit and may have melted something up in there.

Next move is to get one or more relays and move the aftermarket switched circuits to them so the only draw on the ACC circuit is powering up the relay(s).

Sound right?

Charlie Jones

Whatever relays you get , make sure they are " continuous duty " relays .
The Bosch " cube " relays are good for all but the most heavy amperage loads .
Ry 552 Standard Ignition Accessory Power Relay,Anti Theft Relay,Automatic | eBay