Wow, I am a new vette owner after 38 years of dreaming. I purchased a 1985 black vette (76000 miles) for $5000. I had my mechanic go over it completly and it's in great shape - just normal age related and speed related problems.

My dash instrument lights do not work. Fuse is ok and dimmer switch works for the rest of the dash. I am planning on removing the cluster and checking the connector since no lights work in the cluster.

Any advice would be welcome.

Stephen

 

There are 4 backlights and when you take the dash cover off you will see 4 bright silver covers that you remove to gain access to the lamps which are quartz halogen #882 lamps (about $8 each). These lamps have two parallel pins and plug straight into a socket. Don't turn the lamps when you remove them to determine if they are blown out (likely). Wrap a piece of masking tape around the lamp and stick the ends together and use a needle nosed pliers on the stuck together ends to remove the lamps. The sockets are push in /turn from the rear of the circuit board and ones with many hours sometimes don't make good connection to the circuit board due to the high operating temp of the lamps causing oxide on the fingers of the sockets that make connection to the circuit board. If you loosen a socket you will have to remove the cluster and take the cluster apart to reinstall the socket (be careful). If the lamps are ok, or if you replace the lamps and they still don't light, most likely you will have to take the cluster out and perform the next inspection:
The cluster has 2 printed circuit boards that plug together with a single row of pins on the front board (as driver sees them) into a socket on the rear board. The end pin closest to the center of the circuit board carries the lamp current and this current through a resistance connection due to an age relaxed spring on the socket makes enough heat to unsolder the pin on the front board and the backlighting becomes intermittent or totally dark. Resoldering the pin will not cure this problem (it will for a little while). I cured my 87 by soldering a short piece of small insulated hookup wire from the pin to the socket and haven't had a problem now for 6 years.

 

Does the cluster just not light up at all, or can you still the the readouts but just dark?

If just dark, it's probably the backlight bulbs. As jfb said, there are 4 of them. Bulb#882

If the bulb holder (the base) is not broken, you can just remove the front trim panel and replace from the driver's seat. They turn the key "on" but don't start the car and look at the bulbs. Pull the old one(s) out with pliers carefully, and push the new one in carefully. The holders get brittle with time and heat. If he base is missing or broken, or if you break it putting the new ones in, you need to remove the cluster from the car, open it, seperate the two circuit boards, and install the new bulb with holder from behind.

 

THANK YOU! My first time using the forum and the info is fantastic. I'm going to mess with the bulbs after work today and I'll let you know.

Stephen

 

Ok, I checked the bulbs and they are ok. I did not check the bases which I saw the instructions after I worked on it tonight.

I attempted to remove the cluster and it is going ok up the disconnection of the wiring. I want to be careful so I'm asking before I force things.

The two electrical connnectors, both black, do they just push into the cluster? I tried to gently pressure them out with a screw drive and they do move but there are also the grey and blue (I believe wire retainer clips on each connector). How do I remove these connectors?

I did remove the drivers info panel to be able see to see what is going on.

Stephen

 

Make sure the retainer clips have been removed. The connectors have a lot of pins and it takes some muscle to unplug them.

 

Thank you to the people who answered my thread. The job is done. I have dash cluster lights and I’m looking forward to my first drive at night. After removing the cluster bezel and the four stainless steel covers for the light bulbs I removed the bulbs. Two of them tested bad with my continuity meter so I knew it was not a bulb problem. I followed the procedure in the Haynes Repair manual and removed the dash cluster (this involved dropping the steering wheel.). Note: The wiring harness to the cluster has a metal locking clip to hold it to the cluster. Mine were on the back side of the connectors, out of sight, and if I had not taken my time I would have forced the connectors off with some damage. Disassembling the cluster it was obvious there was heat damage to the circuit. I re-soldered the two end connectors as instructed and tested the circuit again with my continuity tester. I cleaned the contact surfaces for the bulb bases and re-bent the connectors on the bulb bases. The upper two bases were burned brown so I re-installed them at the bottom of the cluster. Note: The local auto parts stores and the Chevy dealer were no help. NAPA took one look at the bulbs and bases and retrieved them from the shelves. I could not get the cluster bulb bases, only the bulbs and the turn signal bulbs and bases. After plugging in the reassembled cluster and making sure it worked the rest of the re-assembly went smoothly.
Again thanks to the guys who gave me key info to know what to look for in the cluster. I hope this summery helps anyone willing to tackle the problem.

Stephen

I have pictures but have to find a place to put them on the web to link them to the forum. If anyone is interested in the e-mail me at scmann@12verizon.net

 

Glad you got it working and welcome to the forum!

photobucket.com is a good place to put up your pics also.