cabin heat?/ curse of the c3!
dome light wont come on from headlamp switch
only from doors opening and shutting
blower motor only works on high speed


cruise control not working cant seem to get power to the transducer
lighter doesnt work
clock

 

Do a forum search on each topic......you will find many solutions there....

 

thanks ive been doing that

 

power locks stiff and not working?

sending unit reads too high temperature already put in a new one-
You might have a ground problem in the insturment cluster.

bouncy speedometer-Spend $30 and get a new one and grease it correctly before installation. If that dose not fix it then the SpeedO has to go out to someone who fixes them.
cruise control not working?

lighter doesnt work-check the fuse and ground

clock-I did not know that they ever worked for more than a year or two.
http://corvettec3.ca/clock.htm


windshield washer-I gave up and installed a new one and ran a "Bubba" switch under the steering wheel.

left turning signal slow and dash arrow light not working
horn-I would check that both the front and rear lights are working well and that you have 12 volts and a good ground.

Grounding is an issue with the C3 plus age.

 

Go back to the first of c3 Tech/performance click search this forum and then show post and type in heater core bypass, for your heat in cabin problem and read what it gives you. Repeat per problem. Hope this helps, Good luck!!!!!!

 

i added a resistor to the new temperature sendng unit and that fixed the gauge reading to high. now if i can get the other problems fixed

 

thank you great 68

 

Cabin heat: Ensure that the vac operated shutoff valve is working on the heater core line. I also use a 90deg ball valve on one line.

Consider putting reflectix and hushmat down to cut the heat and reduce cabin noise. I put it on my firewall, floorpans, tranny tunnel and waterfall. Ensure that your tranny tunnel foam seal is in place too. Also check the shifter boot.

 

Headlight switch rheostat has bruned out.

Resistor under the hood on the case or a bad fan switch.

Fuse; element burned out; no power; or no ground.

Clean it and see if it comes back to life.

 

Clock may be a bit more complicated. Get a repair kit from one of the vendors when you clean it.

 

On the dome light, saw a post speaking of removing the time delay for interior lighting would dis-able dome light at the headlamp switch....door switch only would operate it.

 

That dome light timer is a huge PITA.

I finally took the bulb out of the dome light. Don't miss it at all.

If the timer is out, I would leave it out. It's very annoying and GM stopped using them.

 

Fan speed problem.....
Remove the relay under the hood, the one on the firewall pass side.
Open it up and run strip of sandpaper between the points.
Solved the problem on 2 of my Vettes.

Cabin heat......
Agree with the post to check the vacuum switch. On top of the heater box behind the glovebox there it a vacuum SWITCH operated by a cable. Make sure the switch plunger is being fully depressed.
Took me 25 years to finally get around to checking out that switch on my black79 I always wondered why I had ice cold AC upon starting till the motor warmed up!
And make sure the vacuum valve along the pass frame rail in the heater hose is operating.
OR, don't worry about the vac switch or valve and install a manual shutoff valve in the heater hose.

Lighter.....
Like mentioned, bad element? Try plugging in a phone charger or something like that see if you get anything.
Maybe bubba tapped an aftermarket radio memory into the lighter wire. Seems a common way it gets done.
Lighter is on the "courtesy" fuse and it sounds like you got interior lights. Clock is too, but original clocks don't last 35 years! Rebuild the clock or go with a quartz movement. Either way is available from any of the vendors.

Cruise.....
Who knows But keep in mind the cruise only works above 30 mph. Have you tried it at high speed?


edit....just noticed this thread is 2 years old

 

For your cruise, try this web page. Nice write up. http://www.splashedpaint.com/cameron...iseControl.pdf

The lighter, I have had problems with mine.
Cabin heat, Add a good insulator on the floor and transmission mount, Transmission collar, seal the AC cover and ensure you have a good seal on the hood. Another good tip would be to add a heater shut off valve to stop the hot water from flowing to the heater core.

Dome light, by pass the dome timer. If that doesn't cure it I would say its in headlight switch. I would not order one from the parts store due to the most of them will not have the vacuum ports for the headlights.

Do a search on the clock repair, there are repair instruction out there. If I can find the website I will post later on. Took mine apart and cleaned it up and works perfectly now. If it goes out again I will go digital.

Hope this helps.
Ron

 

Thanks to all you guys know everything!

 

bypassing the door timer probably caused it not to work at headlamp switch unless its the rheostat like EasyMike said. wiring can make you nuts