Help....AAZ Speedo Cluster

[aadonline]

Hi all:

My Speedo cluster stopped working. I got another one from pick and pull. But its for a TDI and now my tach reads like 9000RPM and over. Is there any other way I can make it work?  I am getting signal from the W terminal at the alternator. And I know that the tach was working with the old cluster.

Its on a 94 Jetta TD (AAZ motor)

Thanks

[Rabbit on Roids]

pretty sure tdi ones read off a crank sensor or some sensor in the injection pump? or is it off the wire on the 2nd injector?

but why dont you just put that speedo in your orig cluster, or put your tach in the new cluster?

[gldgti]

Hi all:

My Speedo cluster stopped working. I got another one from pick and pull. But its for a TDI and now my tach reads like 9000RPM and over. Is there any other way I can make it work?  I am getting signal from the W terminal at the alternator. And I know that the tach was working with the old cluster.

Its on a 94 Jetta TD (AAZ motor)

Thanks

can you swap the old tach into the new cluster?

rabbitonroids is probably right, the tdi tach likely runs from signal from elsewhere on the engine - since you new tach is reading high, it needs a lower frequency signal to be correct, and the W terminal signal is way more tha 1 pulse per engine rev, so that seems reasonable.

[aadonline]

Thanks for your reply guys.

Swaping the speedo or the tach is an option. but I am not sure how to do that..Looks like there will be a lot of soldering and the tach and speedo are attached together.

[Rabbit on Roids]

just cause they are in the same housing doesnt mean they are one piece. all the older clusters had swappable pieces. i dont know why the mk3 stuff wouldnt be interchangeable too...

[burn_your_money]

The MK3 stuff is a lot different then the mk2 and previous clusters. I'm not saying it can't be done as I have never tried, but it won't be as easy as previou generations.

What happened to your old cluster? Usually the solder breaks where the main connector plugs into the cluster. A simple resolder should get you on your way

[92EcoDiesel Jetta]

In regards to the tach, I've done quite a bit of work with the 85-92 MK2 CE1 and CE2 clusters, having just put a tach into my 92 Eco (see this thread  http://www.vwdiesel.net/forum/index.php?topic=20437.45 ). The CE1 MK2 gasser cluster has a standalone tach, but the CE2 gasser cluster has the tach circuitry on the main board so swapping tach is not really possible. I have no experience with the 94 clusters. The only way to find out is to take one apart and have a look inside.

[aadonline]

In the old cluster the speedo is dead. And I am not sure if swaping just the tach alone would work. Can I get that signal anywhere else is a AAZ other than the W terminal?

[Rabbit on Roids]

W term is all you get dude. you need to figur eout how the TDI one is triggered, or just get the right one for your car. TD and TDI engines are so much different, im surprised it even works.

[Vincent Waldon]

The MK3 stuff is a lot different then the mk2 and previous clusters.

Yup, almost positive all of the circuitry on the MK3 cluster is on-board... meaning tach etc won't just swap across.

They are also noted as being a pretty unstable design (search for "cluster" on the MK3 forum on Vortex and you'll get a ton of frustration... issues seem to mainly be around the voltage regulator design.

Because they are surface-mount soldered *and* proprietary from a circuitry perspective very very difficult to reverse-engineer, modiify, etc... unlike the more traditional MK1/MK2 design.

[aadonline]

Hi Guys:

Will a Dakota Digital tachometer interface help. The one in the following link...
http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=128/category_id=287/home_id=59/mode=prod/prd128.htm

Thanks

[Rabbit on Roids]

First, you need to figure out what triggers the TDI tach. if it gets 2 pulses from the engine every rotation, then yea, that converter will work. but if the tach is driven from somewhere else, then its not gonna work. that works good if you have a gas tach to work with.