[s_glem]

TL;DR - 66 Chevelle column shift steering column but have since converted to a manual. Every time I press the brakes the rear fuse blows (brake lights, etc.). I've done a lot of troubleshooting and found that the issue occurs only when I screw in the turn signal lever into the turn signal switch. More info below.

I first noticed the issue when I picked up my car from the shop after engine and transmission install (406 sbc and TKO600). I ended up unplugging the brake switch so I could at least use the headlights on the drive home. Since then I've gone through a bunch of the wiring in preparation for a new instrument cluster so I can start the odometer at zero for the new engine. During this process I noticed the wires coming from the turn signal switch got pinched between the column and I thought for sure this was my issue.

I tested a new turn signal switch without the column (I removed the entire column for primer and paint) and it worked. However, I recently put the column back in and noticed the issue is back. I took the column apart and tested with just the turn signal switch again and it worked. So I added the column components one at a time and tested again and again until it failed only after screwing in the turn signal lever. Any ideas? I'm no electrical or car expert and would appreciate any help, thanks!

 

[DUTCH MAX HEADWORK]

Check the condition of the wires that run through the column by unplugging the turn signal ribbon connector under the dash on the column. Install your turn lever correctly, then use an ohmmeter to make sure no terminals in the connector go to (have continuity) ground. Place one lead of your ohm meter to a good ground and the other use to check each terminal. None should be a closed circuit or have continuity to ground. If you show continuity, then your wire or switch are grounding or shorting out to ground. Try this for each position of the switch. The only wire there that should go to ground is the black wire when the horn switch is depressed.

While the turn connector is still disconnected, with a good fuse step on the brake. If the fuse doesn't blow, it will give a hint which wat to work this. If it blows with the turn connector disconnected, then the issue is in the circuit from the stop light switch to the turn connector at the end of the harness.

 

[B52bombardier1]

Very good, methodical and deliberate advice. You can't go wrong with this kind of troubleshooting.

Rick

 

[s_glem]

Check the condition of the wires that run through the column by unplugging the turn signal ribbon connector under the dash on the column. Install your turn lever correctly, then use an ohmmeter to make sure no terminals in the connector go to (have continuity) ground. Place one lead of your ohm meter to a good ground and the other use to check each terminal. None should be a closed circuit or have continuity to ground. If you show continuity, then your wire or switch are grounding or shorting out to ground. Try this for each position of the switch. The only wire there that should go to ground is the black wire when the horn switch is depressed.

While the turn connector is still disconnected, with a good fuse step on the brake. If the fuse doesn't blow, it will give a hint which wat to work this. If it blows with the turn connector disconnected, then the issue is in the circuit from the stop light switch to the turn connector at the end of the harness.

Thanks for the help! With the turn signal lever disconnected, I am not getting continuity to ground on any of the wires. With the lever connected, I am getting continuity to ground on the green, black / yellow, and black / white wires. I think my issue may be that the lever is ever so slightly contacting the terminal below. I forced the wire and terminal to seat further and am no longer getting any continuity to ground.

 

[billdini]

Take it off and round the corners off on the bench grinder. Very likely cause.

 

[vortec710]

Score another one for the wiring wizard, and I mean this in a good way.

 

[s_glem]

Take it off and round the corners off on the bench grinder. Very likely cause.

Yeah I think I got it to seat properly but will definitely grind some material off just in case.

 

[bop468]

I had this happen on a 66. The lever was coming into contact with the wire connections just below it. I made a thin insulator to go under the lever.