1985 Chevy? I bought the car as a hobby to bring it back up to top condition. The transmission and engine are still good. The problem I am having is that from the start the speedometer and the tachometer never worked, the speedometer does nothing and the tech is pegged to one side. Oil pressure still reads as well as fuel but the coolant temperature stop reading. Does this sound like a problem with the sensors, the computer or the panel itself. I found a digital panel at Summit for $475 range but need to know the best way to troubleshoot this before spending a lot of money for the incorrect problem. Any help would be greatly appreciated, thanks!!
2007-08-19 10:20:30 · 2 answers · asked by salamander492 4 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
In '85 the computer didn't have anything to do with the gauges, so rule that out..
The speedo is cable driven, so check all of that out. It's not un heard of a speedo cable to break, or the lube/oil in it dry up and cable not turn.
Next the speedo/cable is driven from 2 plastic gears in the side of transmission's tail shaft.. So it could be possible for the plastic gears to strip out over time...
The tach works off of the ing. system.. In fact it hooks to the neg side of the coil... In '85 you have a large cap HEI dizzy... Look on driver's side of dizzy.. You will se a square sticking off the cap.. It will have one long plug, and 2 small plugs on the under side of that square..
The front rear plug is the 12 volt hot wire, it's marked "BATT", then next to it will be one marked "TACH" That is where your tack wire hooks... Check your connection, and cond. of that wire..
Water temp sounds like the sender is bad, or not grounding good, or the wire on sender is off/broke, etc.. These senders/holes are pipe thread (tapered fitting) Most people will put teflon tape or something on them to "seal" them, but thats not needed as the fitting is larger as the threads goes up.. With sealer on the threads, it could cause a bad ground between sender and the threaded hole..
Now those digital gauge panels your talking about is NICE.. I have one in my 1988 camaro and love it.
Here's a couple pics of mine for you
http://rides.webshots.com/photo/1289824938041290424rrReAP
http://rides.webshots.com/photo/1289825797041290424rPdVhs
http://rides.webshots.com/photo/1289826653041290424feFkEU
The speedo in them is elec, so you have to buy the sensor.. It screws onto trans in place of your stock cable, then has 2 wires on it that you run up to the speedo and hook up.
As you can see, you still use your stock cluster, just remove OEM gauges and put the digital panel in place of them..
2007-08-19 14:30:08 · answer #1 · answered by chevyraceman_383 7 · 1⤊ 0⤋
Get a factory service manual through Helm.com or Eautorepair.net for online access for a fee. Manual should have trouble shooting charts for the dash/speedo/tach. GM electronic dashes in those years were known to have problems and with that many things not working, sounds like an electrical dash problem or bad ground but without knowing the maintenance of the car, it could be anything electrical. Maybe try getting one from a salvage yard or a company that repairs them.
2007-08-19 10:47:50 · answer #2 · answered by paul h 7 · 1⤊ 0⤋
that sounds like more of a problem with the sensors than anything else with it,and i have used the custom dashes from summit they work excellent,and look good too,but this would be a problem with the sensors or the wiring harness where it plugs in to the back of the dash,i have had problems from that on some of them before,good luck on it.
2007-08-19 11:42:24 · answer #3 · answered by dodge man 7 · 1⤊ 0⤋