Having a real hard time with an electrical problem.  Been one thing after another.  I am currently pulling my hair out on this.


Headlights work fine

Marker lights work fine

Break lights work fine

Rear lights when headlight/marker lights on work fine

Turn signals do nothing

Flashers do nothing

Replaced fuses in fuse panel

Using new turn signal switch(connected but not installed in column)

First Welcome to C2VR.  I had the same thing happen but I knew my turn signal's worked the week before.  What it turned out was the flasher was not seated correctly.  That sounds simple but I had the flasher in and out a couple of times even went and purchase a new one and that did not work either.  was frustrated and started all over again with the flasher and it started working.  I backed off real carefully. 

Do you own a set of electrical drawing for your car or better yet the GM shop Manual?  If you do not that is the best and only good authority when it comes to working on your corvette.   The other one I like is the Corvette Assembly Manual which just show you the assembly drawings that were used when they put your corvette together.  I have found it handy. 

The help I'm providing is using my 82 shop manual so if someone else has a correct manual or an 78 car take their advice over mine. 

It is a simple system but that does not mean it is simple to fix if it is in the wiring.  Does your Hazard warning flashers work?  If they do then everything on the other side of your switch is working correctly.  Your switch is new so that basically leave the power going through your fuse box. but if you have a book you already know this if you do not I can copy and pdf a couple of pages of my manual that diagrams the circuit and talks about how it works.  

I work from home so just email me if you want the pages.  Sorry I cannot be of much more help but

I did replace that flasher a half dozen times before it started to work so I'm guessing bad connection in the fuse box.

tb2k82ce2011-07-19 08:53:23

If both the turn sigs AND the hazard flashers are not working, I'd kinda suspect the t signal switch, myself. The turn sigs and the hazards use different flashers, but it is entirely possible that BOTH flashers are bad, or even missing.
IF the indicator lights in the dash are not even coming on when you use the turn sig or the hazard, I'd be going for the flasher(s) first. I think on the '78, the hazard flasher is in the fuse box, and the turn signal flasher is under the pass side dash, at the lower edge. Someone correct me if I be wrong.

[QUOTE=Adams' Apple]If both the turn sigs AND the hazard flashers are not working, I'd kinda suspect the t signal switch, myself. The turn sigs and the hazards use different flashers, but it is entirely possible that BOTH flashers are bad, or even missing.
[/QUOTE]

I have no flashers inside or out.  I also have no signals or flashers.  I replaced the can in the fuse box.  I could replace the other one in the passenger side as well I guess. 

@tb2k82ce

I do own a  pdf of the wiring diagram for my 78 in addition to about every shop manual I could find, Hayes, chilton, Gm, etc.  I reference all of them constantly.

Here is some help welcome to C3VR

Well, I be darned!  Reseating the the can in the fuse box caused the turn signals to start working again.  However, they are really dim and blink awfully fast.  The indicator lights on the dashboard for the turn signals are out, could that cause this? 

I still dont have hazards working. 


I am so out of practice on car electrical.  I have not had to really work on a car like this since the mid 80s with my firebird.

I would recommend replacing the flashers. Just make sure the terminals in the fusebox are nice and clean, with no corrosion.
The indicator lights should have no effect on the signals themselves working.

Adams' Apple2011-07-19 20:07:04

Like I said earlier I pulled and replace my flasher cans over three times and then it all started working.  The slow flashing I would bet is a bad ground or contact.  Again I would suspect the flasher connections.  Blubs are cheap replace them. 

bulbs bad will change the flash rate. power is at the flasher then through the combo switch to the bulbs to ground, bad grounds will also effect the raterraider12011-07-20 10:03:23