I'm a new member and this is my first attempt to ask for advice.
I have 1983 GSL with 12A engine and 5-speed manual transmission that I bought new in 1983. For almost as long as I've had it the tachometer has not worked properly in cold weather. When I first start it the needle doesn't move at all. After a few minutes the needle will move up under acceleration but does not drop back under deceleration. After about 15 to 20 minutes it starts working properly. I've checked and cleaned the electrical connections at the coil and the ground on the shock tower to no effect. (I frequently get a clicking noise from behind the cluster but have always assumed that is coming from the speedometer.) I will appreciate any advice anyone may have to offer.
Thanks.

 

Does the clicking noise happen when the car is moving or stationary?

Perhaps there is an issue with the dash cluster and the tach mechanism itself?

I know a dead tach is more likely a sign of half of your ignition system dying, ie an ignitor going bad.

My FB has done something a little similar on occasion. During cranking and a few seconds after start the tach is dead then comes alive and works fine. It is very rare and more happens with a cold start...

 

I have the exact same issue, mine also affects the gauges. I can reach up under the dash, behind the cluster, wiggle a particular wiring harness and everything will fire to life. On mine, I assume it's contraction due to the cold that leads to a short. I haven't bothered to track it down yet - its usually too cold to work on, and I can't replicate the issue when it's warm...

Like yours, once the car warms up - I have no more issues.

 

Same here, but you have 2 issues going on:

1) the tach is actually the grease on the electric needle assembly that gets tooo thich when it's cold out. That grease is too hard for the electric motor to overcome, which means the needle sticks. As the interior of the car warms up, the grease gets more fluid and the needle functions properly again.

2) the clicking is the speedo cable coming loose from the rear of the gauge and slipping. It is a square cable inside of a plastic sheath with a white plastic clip that holds it into the back of the gauge. When cold outside, the clip can come loose, or the grease in the cable can get thick which adds resistance to turning. The effect is the cable clicks as it tries to overcome the friction. Reach up from the footwell and you can check the speedo cable is secure.

Aside from garaging the car or getting interior heat going quickly up behind the dash cluster, this is just a symptom of an older vehicle.

 

Thanks to folks who replied. I suppose I'll have to remove the cluster to get to the back of the tach. I'll add that to my someday list. Thanks, again. hrh