Tacho With Parkinsons.

[toyota_ae71]

Hey all,

Recently changed my clock cluster in my ae82 to a tacho one.

It works perfect, until the cars temperature reaches almost half way and then it starts jumping around and giving the wrong reading.

Ive pulled it out several times to check the wiring and plugs but still nothing.

Anyone got any idea's?

 

Cheers Corey

[toyota_ae71]

anyone? Its really starting to annoy the crap out of me!

[altezzaclub]

Just to be sure, everything works fine until it warms up, then the temp gauge goes crazy... that right?

 

What does the tacho needle do? That's all sweet?

 

If its is the temp gauge only then the problem is a connection in that circuit, and seeing as it when it is warmed up I assume the input voltage is fine and the voltage being fed to earth through the temp sensor is faulty.

 

Check the resistance through the meter to earth with a multimeter and make sure that is stable, then check the resistance through the temp sensor as it warms up and see if that is stable. If the gauge and the sensor are fine then it must be the connection between them that is intermittent.

 

If you haven't got a multimeter go buy a $10 one from Jaycar or Repco or wherever you can. (http://cgi.ebay.com.au/19-Range-Analog-Multimeter-AC-DC-Ohm-VOLT-Meter-VOM-/260487722805)

 

The old needle ones are best, and they only need to display volts (DC and AC) and Ohms. They are very handy and that's all I use to fix washing machines and appliances at work.

[toyota_ae71]

Sorry, i didn't explain myself correctly :laff: .

The Tacho works perfect until the car gets around 1/4 to 1/2 on the temperature gauge. Then the tacho starts jumping around and giving the wrong reading.

 

Cheers

Edited April 24, 2010 by toyota_ae71

[altezzaclub]

hmmmm...

 

Try shorting the wire on the temp sensor to earth while you take it for a run. That will give you a red-hot temp gauge reading, but it will also remove the temp sensor from the circuit just in case it is an earthing problem you have.

 

Other than that, see if you can earth the tacho out carefully, it may be trying to use the temp sensor as an earth at the moment. I assume there is a common earth for the instruments in the cluster somewhere, probably one wire in the plug.

 

I can't remember what mine looks like and I'm afraid I have no inclination to go into the garage tonight...

[clubby2084]

My AE82 has the tacho dash. The tacho needle started flicking once the car got up to operating temperature (not jumping around and giving the wrong reading like yours).

First the reluctor in the distributor needed replacing, so I had a distributor rebuild.

The problem returned once the alternator started to pack it in. This time the tacho would flick at any time including at idle. I replaced the alternator, problem solved.

Do what Altezzaclub recommends, get a multimeter. Check your alternator.

Good luck

[toyota_ae71]

Thanks a heap. Only replaced the alternator late last year so it should be in A1 condition, ill try either another dizzy or just take it too an auto elec. I can't be bothered with it, specially after working on my race car non stop. :wink:

 

Cheers

Corey

[GJM85]

I got a hold of a dash cluster with a tacho in it for my ae92... when i fitted it all sorts of things were wrong because the wiring film on the back didn't match up to the lume I was plugging it into to. That and my speed ended up 15kph out so after 30,000kms I got really annoyed and changed it back.

I now find it just as easy to drive with out a tacho....

[Trev]

Hmmm so you have:

 

 

 

:wink:

 

If there is something wrong with the contact strip let me know and I will send you one I have here, You just pay postage, The one I have is green 221.

[GJM85]

the one on my spare tacho cluster is green 356.

i have a '90 Ae92 Seca CS. If you think it would fix it I am sure keen!

[DKG779]

When the module on my distributor (AE80) was on it's way out cruising at certain RPM warm engine my Tacho would dance about 700rpm either way of actual RPM. Replaced the module and no more issues with the tacho or reliability !