Newbie posting and to Vette ownership. However, I've been checking/reading up here ever since I was wanting to buy and bought my new to me C5. Lots of great info here but I've got a problem with my C5 that I'm a bit lost on. I've done a search here on the forum & found similar threads/situations to what I'm experiencing with my '99, except I have the Hyperflash cable installed.

The front signal lights were working fine. I switched the bulbs out to LED switchbacks about 3 months ago and at the same time I installed the Hyperflash cable. Everything continued to work, no problems until just last week when the signal lights would flash a few times (normal/no hyperflash) and then just stay on solid/freeze. It does this if signaling left or right. I'm lost/confused as the hyperflash cable is suppose to fix the intermediate/no signal lights issue and it appears to be working as I'm not getting hyperflash.

The DIC displays codes BCM 2578 & 2583 which are the left/right turn signal circuit to ground codes. Just once shown as a current and then all the others times it's done it as a history.

If I reset the codes in the DIC and/or turn the key off then back on, the signal lights will flash normally again a few times then stay on solid/freeze again.

All the other lights both interior & exterior appear to working as they should. DRL's are working, the hazards work with a simple press of the hazard switch (jiggling/cycling them on off will not cause the signal lights to work). I even took out the LED switchbacks, installed normal bulbs and I get the same problem.

Anyone know what may be the problem and suggest a solution to this issue I'm having ? I'm limited as to what work & teardown I can do on the car as a live in an Apt complex with strict rules and I'm not too electrical issue savvy. A Corvette shop quoted me about $120 per hr just to diagnose it. Appreciate any info/insight/suggestions. Thanks in advance.

 

Had this issue with mine. Got a new hyperflash harness and that solved it.

 

I would try a new relay in the Hyperflash. What you describe would happen if it were failing to a closed position as it was heated.

Should be able to get one at any auto store. You will need to get a heavy duty one if you plan on putting LEDs back in.

 

Educate me, what is a hyperflash harness and why would U need one and where do they go. Thanks

 

You use one if you are switching your signal lights to LED's. Hyper flash is similar to the effect of when you have one signal burned out and your signals blink very fast. LED's change the resistance therefore you need a hyperflash harness to correct the Hyoerflashing effect. There are a few ways to accomplish, one is with resistors on the led's second is with a harnes that plugs into your blinker module under the drivers side dash. You have been educated!

 

I agree it can address fast flashing with LEDs, but there is more to it than that.

It can be used to replace the flasher unit in the Hazard switch if it has problems. It can be installed between the steering column and the Hazard switch in the wiring. No cutting of wires, just unplug a connector and plug it into the harness. Many people do not want to go into the console to replace a problem Hazard flasher. You only need to remove the knee bolster to install it which is simple to do.

Understand, there are a number of other switch contacts in the Hazard switch that remain in the circuits and they can go bad but rarely do. The flasher unit seems to be the problem child.

 

Thanks for the suggestions. So I went ahead and replaced the relay in the hyperflash harness (it had no name "universal type" one originally) with a Novita EP35 relay. Seems to all be working well again. Appears the "universal type" that came with the harness was going bad even though I was not getting hyperflash with it. Much thanks and kudos for your input. It with about 30min max for removing/installing and $5.00 for the relay (had a save $10 bucks coupon) has apparently saved me at least a Benjamin +

 

Excellent. I like simple fixes.

 

This is one reason I hate to mess with original eqp. it seems you have to add something else to fix the mod you just installed and then it leads to another problem. I don't really care about light upgrade since I rarely drive at night anyway. just my 2 $ worth. Thanks for educating me

 

I rarely help people who have done mods because most have no schematics they can share and I am not into long distance research projects. This was different and appeared to be a no brainer. In addition he had already gone back to stock bulbs struggling to resolve his issue.

The Hyperflash devices are fine but like everything that uses electrons and mechanicals you can expect random failures.

 

I read somewhere where if your flashers stopped working you could exercise your hazard flashers and they would work. I was having no problems but decided to exercise my hazard anyway and then I began having a problem with my flashers. Comes and goes but so what is the fix, can i install the hyper flasher and eliminate the problem? Where do I get one and where do I install it, I don't want to tear the dash out to fix it if I can install it as you suggest in this thread. Thanks

 

I am like you also!! when it comes to especially electrical stuff its best to leave it original !I hear so many members on here screw around with electrical upgrades and they wish they never have !

 

Sent you a PM with my phone number so we can discuss your specifics and fix the problem.

 

The main reason I replaced my front bulbs is because of the heat the original bulbs put out. They melt the housings as they are really close to the top and then water gets into it and blows the bulbs. The LED's don't put out enough heat to melt anything. I had to replace my original housings so I looked for an alternative that might help eleviate this problem. The LED's are brighter and I think look better too. The harness is an easy install too.

 

Thanks, i got it, will try to get up with u next week

 

My first harness had a terrible job on the crimps. One wire even fell out of the terminal. They sent me a new one. Better construction, all the terminals were also soldered. Yet I still occasionally lost brake lights. After tearing the dash apart and pulling the factory flasher unit I discovered the problem was the harness again. This time though all I had to do was run a ziptie through both halves of the connector and pull it tight. Never had an issue since.

Where'd you find the flasher? I need one for another project.