Tach not working

[Dburger]

Guys,

I'm having a problem with the tachometer in my 1981 Cutlass Calais. The steering column was changed out (has a column shift column now, shifter is still on the floor). Rally gauges. All other gauges work but the tach. 231 V6 car if that matters. Any help?

Edit: When I turn the key on, the tach goes from about 1500 RPM to zero. When I turn it off, it does the opposite.

 

[jae]

There are a few things to check:

The tach output at the distributor

The jumper on the back of the gauge cluster – sometimes these get loose, causing an erratic tach or fall out. You can solder the jumper in place – also verify that the jumper is in the correct position

The tach leads / circuit board could be dirty or have a break in it – these can be cleaned with an eraser in a pinch but the best is to use the correct cleaning tip

A grounding issue / problem with the headlight / dimmer switch. Know it sounds funny but my ’82 Calais did something similar – turn the parking lights on, the tach wouldn’t work until you adjusted the dimmer to just below turning the interior lights on. Turn headlights all the way on, no problem; not lights, no problem. Corrected the switch grounding, everything was good

The tach going from 1500 or idle / shut-off RPM to 0 is normal, tach's not getting a signal with KOEO (Key On, Engine Off). Also going to a higher RPM is normal, will vary every time you turn the engine off. Sometimes my '86 goes to 2K, 3K; other times it stays at 700 idle speed. Every Olds I have/had except for the '89 (digital dash) did the same thing.

 

[Dburger]

There are a few things to check:

The tach output at the distributor

The jumper on the back of the gauge cluster – sometimes these get loose, causing an erratic tach or fall out. You can solder the jumper in place – also verify that the jumper is in the correct position

The tach leads / circuit board could be dirty or have a break in it – these can be cleaned with an eraser in a pinch but the best is to use the correct cleaning tip

A grounding issue / problem with the headlight / dimmer switch. Know it sounds funny but my ’82 Calais did something similar – turn the parking lights on, the tach wouldn’t work until you adjusted the dimmer to just below turning the interior lights on. Turn headlights all the way on, no problem; not lights, no problem. Corrected the switch grounding, everything was good

The tach going from 1500 or idle / shut-off RPM to 0 is normal, tach's not getting a signal with KOEO (Key On, Engine Off). Also going to a higher RPM is normal, will vary every time you turn the engine off. Sometimes my '86 goes to 2K, 3K; other times it stays at 700 idle speed. Every Olds I have/had except for the '89 (digital dash) did the same thing.

When I was testing the lights and turn signals the tach still was at zero. Distributor is okay. Thanks for the other information. I'll have to take the cluster out.

 

[jae]

No prob - the cluster is not difficult to take out; the main issue is hooking up the speedo cable on re-install. With the cluster out also a good time to clean it up, replace bulbs, check for breaks in the traces...

 

[Highwood Malibu]

There are a few things to check:

The tach output at the distributor

The jumper on the back of the gauge cluster – sometimes these get loose, causing an erratic tach or fall out. You can solder the jumper in place – also verify that the jumper is in the correct position

The tach leads / circuit board could be dirty or have a break in it – these can be cleaned with an eraser in a pinch but the best is to use the correct cleaning tip

A grounding issue / problem with the headlight / dimmer switch. Know it sounds funny but my ’82 Calais did something similar – turn the parking lights on, the tach wouldn’t work until you adjusted the dimmer to just below turning the interior lights on. Turn headlights all the way on, no problem; not lights, no problem. Corrected the switch grounding, everything was good

The tach going from 1500 or idle / shut-off RPM to 0 is normal, tach's not getting a signal with KOEO (Key On, Engine Off). Also going to a higher RPM is normal, will vary every time you turn the engine off. Sometimes my '86 goes to 2K, 3K; other times it stays at 700 idle speed. Every Olds I have/had except for the '89 (digital dash) did the same thing.

X2
I had problems with my cluster all the time so when I removed it I noticed there where breaks in the circuit. Removed it and replaced it and all of a sudden everything worked perfectly. Dburger, don't worry about where the tach settles after turning the engine off, mine always did what you are describing. Once the car is running is when the tach is accurate.

 

[crazy87]

What about when one reads very higher then normal? reads 3 to 4000 rpm while in town and buries itself when on the highway.

 

[celticsam]

Just fixed the high tach problem on mine last week. Pull the gauges, and either solder a permanent jumper in place of the removable jumper or clean the contact pads with a small piece of scotch bright...don't get too aggressive. also clean and, if necessary, re-bend the jumper itself. In theory, that would fix it as well...I just soldered mine to eliminate any chance of failure. Clean all of the contacts while you are there, and take the advice from the other members...clean and change your bulbs.

Neil

 

[Dburger]

Is it unusual if my stock buzzers still work?

 

[littlerascle59]

Is it unusual if my stock buzzers still work?

Are you talking about the door chime? If its still working properly and you can actually hear, that would be a good thing. Out of all my cutlass none has ever worked properly.

 

[Dburger]

Is it unusual if my stock buzzers still work?

Are you talking about the door chime? If its still working properly and you can actually hear, that would be a good thing. Out of all my cutlass none has ever worked properly.

The "key in ignition" chime and the "key turned on" chime both work. (2 different sounds) More like a buzzer than a chime to me.