Well, I realized when I pulled into the office garage this morning that my tail lights are not coming on when I hit the brake pedal (saw a reflection off the car in the spot behind/opposite me and noted the lights were not on with my foot on the brake pedal. Not sure how long this has been the case. My blinkers work properly, parking/running lights work and they do light up the tails but they just don't come on when I hit the brake pedal. Any thoughts? Know the wire color for the brake/tail lights? Thanks in advance.

 

Try first just an adjustment of the SLS at the pedal. Until you confirm SLS position to pedal there's no reason for other concerns. Do you need an SLS? Possibly and then year will matter. FSM will have all of the wiring information you could possibly need.

 

Thanks WVZR-1, I do have an FSM and will look SLS up in it tonight when I get home from work. Not familiar with that item (the SLS), but I'll check that first. It's a 1996 LT4 CE coupe.

 

In a 96 the Stop Light Switch ("SLS") wires of interest at the switch are orange = hot at all times (From fuse #8), white stop/turn (input to turn signal switch) and also becomes a lt blue wire at a splice in the harness that goes to the center brake-only light and the ABS module.

I'd start by checking the STOP/HZD fuse #8 in the instrument fuse center.

 

Checked the fuse and it’s good so thats
not it….sure wish it was tho! Guess it’s the sls, which, of course is unobtainium. Wow, what a pain. I’ve looked for like two hours online and found only one used one on eBay. Would really like to get a new one if I could, guess thats an unreasonable expectation tho.

Totally don’t look forward to removing the dash panel and getting up under there. What a pain.

If anyone knows of a place to get that part, other than eBay, please let me know. The lone eBay one looks worse than mine prolly does.

Guess this is what I’m doing this weekend, at least messing with it, I’m sure I won’t
be able to get the part before Saturday. Maybe it just came loose or needs a little adjustment.

 

Also, the CHMSL is not coming on when hitting the brake pedal either so I guess that pretty much narrows it to the sls.

I see in the FSM where that white wire splits to the lt blue to the CHMSL while the white goes to the brake/tail lights via dk grn and yel.

 

I've posted a few times with the 'accepted' solution for the obsolete/discontinued SLS for '93+ Corvettes. It's out there and I believe I've done it very recently. Until you check SLS at pedal and some electrical test you don't really know. Adjustment corrects probably 80+ percent of issues.

 

Good to hear adjustment gets 80+ percent, hopefully mine will be in that category.

I’ll search for your post regarding the 93 and up solution. I stumbled across a post from 2014 but that wasn’t it.

I did locate the diagram in the FSM. I’m a good DIYer and am analytical and detail focused, but am not an engineer, so I’m learning some of the FSM stuff as I go.

 

Would you mind sharing the accepted solution? I searched and found some recent discussions where you noted a solution but I did not see what it was specifically. Is there an option to pick up an SLS that will work for 93 and up C4, or parts to fix as existing SLS, at a local AZ or O'Reilly's? I'm planning to take the lower driver side dash panel(s) off this Saturday and try to fix it....hopefully, it just need adjusting, but would like to have access to the part/local solution that day as a backup. Thank you in advance.

 

I am not familiar with the 93-up SLS assembly. Looking at the image above it appears that there are two components on the brake pedal. A vacuum release for the cruise control, and another switch with two electrical connectors.

My hunch is that the electrical switch has two sets of contacts. One normally open for the brake lights. These would be the orange and white wires. The other set is normally closed and are for the cruise control. I didn't look it up, but cruise disengage wires are usually gray or gray/black. Ok, I did look it up: Lt green and a brown.

I'd remove the switch and see if it can be disassembled and the contacts restored. Or take the switch to a chain store and see if you can find a two-terminal normally open replacement that physically mounts into the location. Connect the orange and white wires to the new switch.




For the cruise wires: Obtain a 12V 'cube' relay.

Put the (2) cruise wires (gray and/or gry/blk?) from the old switch on terminals 30 and 87a. (These are the Normally Closed contacts.)
Tap the white wire and connect to #86. (The white wire is powered with the brake pedal depressed.)
Connect #87 to ground.

Another possibility to the above: The existing vacuum switch with no wires on it is almost certainly a N.C. set of contacts. Transfer the lt grn and brown wires (in the blue connector) to the vacuum switch. Done. No relay required. Note: A 6-speed car will not have the pink and purple wires in the blue connector as these are for the TCC in the automatic.)

WVZR's work-around is probably simpler. I'm curious to see what he suggests. Cheers.

 

This post 1st in the thread is a snapshot of '93+, it's 2 switches joined with a threaded plastic plate that was sold as a single part number. Most any GM SLS will and can be substituted for the electrical aspect of the '93+ GM# 10211657. I've posted a few part numbers that in the after-market should substitute for the electrical aspect. All are available 'local'!

Notice in the snapshot the cavities that DO NOT have a connector available in the car harness and aren't needed!

cruise control won't engage 96, also a mystery connector? - CorvetteForum - Chevrolet Corvette Forum Discussion

Ether of these 2 numbers should interchange locally for a fix if needed.

If you need what you imaged there use these GM numbers for maybe an interchange at NAPA or your favorite local might do for you. 25551819 or 10170430. The 93+ is a combination switch that hasn't been available for quite some time. Whatever you buy and if it's a fix be sure to post it. Do the diagnostics first and don't just be throwing parts at it. Do you have the FSM (Factory Service Manual)? I've suggested those previously and they've been mentioned to work.

 

Very much appreciate the info IHBD and WVZR-1. My plan for the weekend is to get the oem SLS out of the car and clean the contacts and reinstall. Hopefully, that’ll solve it. Actually, before I remove it, I will try to adjust it and see if that solves the problem. With that part number, 10170430 (for some reason, I could only see one number), I was able to source that at an Oreillys so I’ll run by there and pick it up on my way home from the office tomorrow, and have that as a backup, it was like $14 bucks.

Only wanna be under the dash once!