Blinkers

[Bryan Kuban]

Ok, so blinkers work fine while headlights are off. When headlights are on the corner blinkers do not work. Any ideas as to what might be causing this on a 89 SHO or is this normal?

 

[luigisho]

Are you talking about the one integrated on the headlights or the side bumper cover?



I don't have my car parked at my place otherwise I would go look.

 

[Bryan Kuban]

Are you talking about the one integrated on the headlights or the side bumper cover?



I don't have my car parked at my place otherwise I would go look.

 

[Bryan Kuban]

The side marker light I be lieve are only on when the headlights are on. The corner blinker is what I am referring to.

 

[SHOrod]

If I'm understanding correctly which light isn't working (an actually blinking turn signal rather than the cornering light that stays on while the turn signal is operating), the symptoms sound very characteristic of a bad ground. When the headlights are off the ground connection is made through the headlight and associated wiring, but when the headlight is energized there is no longer a path to ground potential.

-Rod

 

[luigisho]

I wish I had easy access to my car but it is parked far away from where I live currently. If I am getting this right, you are referring to the orangish corner of the assembly? If it is supposed to flash and it's having difficulty my first thoughts would be the light switch with the integrated dimmer has always been a problem area for shorts and such.

 

[BaySHO Performance]

Might be a problem with the multifunction switch. The 89 switch has been known to overheat and break down the connections. I recently had a case with an 89 where smoke came out of the steering column and the headlights stopped working. What one of the connectors looked like:



And inside the switch itself:



So it might be an idea to check out the switch connectors for signs of overheating. Not sure about the ground problem mentioned as there's nothing wrong with the blinker circuit: they work headlights off.

The switch was redesigned for the 90s on. Went from three connectors on the 89 to two for the later years. I was able to get a replacement switch from SHO Source and installed relays in the headlight circuit to reduce the amps going through the switch and eliminate the possibility of it overheating again. An added benefit is the ability to now upgrade the headlamps from 55 watt to 85 watt. Downside is that the LAMP OUT is on with the headlights dimmed but off on full beam. Same thing happened with the old Competition Limited setup.

The cruise control servo module is bolted to the radiator support (no ABS to get in the way) and its bracket provides a perfect place to mount the relays. Green and red wires cut to insert the relay wiring, relay ground point:



Bare wires twisted and soldered together to avoid bulky, less reliable butt connectors:





Relay power off the starter solenoid: