Digital Dash Problem
Thread Starter
2nd Gear
Joined: May 2006
Posts: 2
Likes: 0
Digital Dash Problem
Hello,
I am new to this group. I have a 1984 Corvette with a digital dash problem. When you turn the key to the on position the complete dash comes on the looks perfect. However when you start the car then entire dash starts to go crazy. Things go on and off, speedo will go up and down when not moving. Sensor numbers turn on and off, etc. Sometimes with I rev the engine up everything goes to normal. I tried a new ground, etc. but can not seem to find the cause of the problem. It seems like electrical noise from the engine is messing up the display. Any help would be greatly appreciated.
I am new to this group. I have a 1984 Corvette with a digital dash problem. When you turn the key to the on position the complete dash comes on the looks perfect. However when you start the car then entire dash starts to go crazy. Things go on and off, speedo will go up and down when not moving. Sensor numbers turn on and off, etc. Sometimes with I rev the engine up everything goes to normal. I tried a new ground, etc. but can not seem to find the cause of the problem. It seems like electrical noise from the engine is messing up the display. Any help would be greatly appreciated.
Guest
Posts: n/a
I am confused about the speedo going up and down but have seen tachs do this when the isolator/filter is either wearing loose on the wires or not bolted to the back of the engine to give it proper ground. I don't know if this is your problem, but look for a silver cylinder about 1/2" diameter x 2" long with a bolt tab on it's side and a brown wire on each end mounted just to the drivers side under the distributor bolted to back of head or a trans/engine bolt. It is really hard to find and moving it too much can cause the wires to wear through on each end. It is a good place to look if you have tried other grounds and ecm connections.
Sorry...DBL checked it should be a white wire but usually turns brown with age.
Sorry...DBL checked it should be a white wire but usually turns brown with age.
Last edited by todd_vette; May 27, 2006 at 01:30 PM.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Hmmmmm, when I last tuned my 87 I installed a new cap and coil (I was chasing a miss) anyway, my dash started acting just like yours, Thought maybe...just maybe I had crossed the coil wires, pulled the cap off the coil..and guess what, one of the coil wires (there's two little ones attached to the spade connectors, battery and tach) one had gotten pinched and was in fact arcing, fixed that end of digi dash problem.Good luck 
Thread Starter
2nd Gear
Joined: May 2006
Posts: 2
Likes: 0
Thanks for the replies. I think it may be something in the ignition system. I purchased the car with the problem so I do not know what was changed. When I was driving the car home it died. It turned out the ignition module burnt out. I put a new distributor, rotor, coil and module. The car runs well again, but the dash is still crazy. I am wondering if I have a bad spark plug wire or shorted plug. I will change them on Monday and try again. If anyone has other ideas, let me know.
Thanks.
Thanks.
