Speedo/tach from a VW Fox

[crazyvwvanman]

The 2wd Vanagon cable speed is only about half the speed of all the others including Syncros. Too far off for a simple needle preload tweak. The Fox odometer would count at half distance as well the needle indicating only half road speed.

Mark

[Vanagon Nut]

Thanks Mark.

Oh well. If it's "too good to be true".....

Glad the fix to my diesel speedometer is working.

Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Vanagon Nut]

So bumping this again to provide info on where I sourced the Fox part locally.

VM Autohaus in Burnaby BC Canada. I assume they found it through VW of Canada (possibly VW of US too?).

At $175 US for a rebuilt from GW:

http://www.gowesty.com/ec_view_details.php?id=4241&category_id=&category_parent_id=

I get how a Fox speedo might be a good alternative.


Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[kjono09]

Just to be clear, the fox tach fit in the dash cluster?
_________________
84 Retro-Westy GW 2.2L (Vincent)
67 Bug 2007cc (WBX in progress) (Davey)

Submariner

[crazyvwvanman]

Not enough info in your question.

The Fox tach can fairly easily replace an existing Vanagon tach in a stock Vanagon tach cluster.

The Vanagons clusters with a large analog clock have the fuel and temp gauges in the wrong locations compared to a Fox tach. If your hope was to add a Fox tach to replace the large clock then that is much more difficult.

Mark

[davevickery]

This is an old thread, but has a lot of good info related to subaru vanagon tachometers. Thanks to Edgood for posting details. I just ordered a used tach for my 89 Syncro off ebay. It looks identical to the stock tach except the back is white plastic instead of black and it has a higher redline which matches the subaru 2.5 redline. I somehow managed to break my tach by messing with it too much. It was pretty accurate, but I wasn't satisified and wanted to adjust it a little bit. Errr.

This one is from an 85 Jetta and appears to match the 84 FOX Tach shown in the beginning of this thread. There were a few other models with the same tach on ebay but you have to look closely, many don't look exactly the same. This has the same gauges and the electrical connections on the back look identical. Someone said their 87 Jetta tach was also an exact drop in replacement, but the later years I saw looked different so I am not sure about other years. I think it is basically the early MK IIs that work, from 84-88.

Anyway, it is good to know there are some inexpensive used clusters to be found that have compatible tachometers. The speedo doesn't sound like a direct replacement but is the right gearing for a syncro so you can make it work in a pinch.

I think this tach may be equivalent to the '85 Vanagon tach and not require any mods to read the subaru ECU signal. If not, I'll have to swap out resistors like on the 86+ vanagon tachs.

[davevickery]

Just an update on the Jetta Tach for a Subaru Vanagon. It was not as simple as I thought but still good for anyone that has late model tach with their subaru and probably other 4 cylinder conversion.

The 85 Jetta Tach (marked 8/85) is indeed SIMILAR but not exactly the same as the 85 Vanagon tach. I did not need to modify ANYTHING to use it with the subaru conversion. That was the good news.

But this particular one is not a direct drop in replacement. I had to take both tachs completely apart and swap the guts from the Jetta tach into the Vanagon housing. The plastic backing and mounting holes don't line up. I might have been able to tape it on but there were also an electrical difference on the backing plates of the 2 tachs that I hadn't notice before. The 7K RPM face plate screw holes also don't line up so I didn't use it (although it would be easy enough to drill a couple holes).

At this point I was thinking this is not going to work. The 2 circuit boards don't look anything alike on the inside. This picture below doesn't show the Jetta tach as I had already swapped them. But it shows how much you have to disassemble to do this.

Since I had them all apart I decided to swap it and try and to my surprise it works fine. A tiny adjustment to the potentiometer raised the reading to be pretty close (and close enough for now). I learned my lesson about fixing things that aren't broke.

So hopefully this helps someone down the road. I think even though I had to completely disassemble the tach to use the inner electronics, it still might be easier than removing and resoldering resistors on an 86+ tach if you have an engine conversion that uses the tach signal from the ECU.

[dlb154]

Davevickery,

Screw holes of the 7k tach face are close and if you angle the screws and tighten a little at a time, alternating from screw to screw, the face plate works fine.

This is what I did and also added a strip of matt black vinyl to the bottom of the face plate that is short of meeting the bottom opening of the Vanagon cluster housing. Without doing this, there is a small opening. I can post a picture of this added vinyl if anyone wants to see.

[davevickery]

[crazyvwvanman]

Yes, I have found the holes are close enough. I have done it many times by putting one screw in most of the way first, then flex the other screw post over till the hole in it lines up with the hole in the face. Then put in the second screw. The screw to put in first is the one closest to the needle. That way you don't have to work near the fragile needle while doing the trickier screw.

Mark

[davevickery]

Help! Swapping in the Jetta tach has thrown off the excite circuit for the alternator warning light. The light no longer comes on and the alternator was only charging intermittently flipping on and off anywhere from seconds to minutes.

I bought a new alternator not realizing this has to be because of the change of tachs. The alternator warning light does not come on and I get no charging. I'm assuming this NAPA rebuilt alternator expects a stronger signal than the subaru alternator, but either way, both alternators are not working right after swapping in this tach.

I pulled the cluster and the foil looks fine. I tested continuity and everything looks good. The diode on the blue wire, pin 11 seems to be working properly and only flows current out to the alternator and is blocked in the other direction. Power to that bulb runs through a resistor and it seems good with some resistance when I checked it. Plus all my other warning lamps work so I think power is o.k.. There are no breaks in the blue foil anywhere. I checked continuity from the dash plug (pin 11 blue wire) to the alternator plug and it all looks fine. And pin 2 of the alternator plug is getting battery voltage as it should. So it has to be something with the tach swap.

Anyone swapping in one of these tachs I think should have seen the same problem. Any ideas? Or a source for a replacement potentiometer so I can fix my old tach? Many thanks, I realize there are probably only a handful of people who can answer this, so I am grateful if someone chimes in.

[crazyvwvanman]

The tach doesn't connect to the blue wire. The back of the tach has a 3 pin connector and that is only connection the tach makes to the blue foil. Why not unplug that small tach connector to check if that somehow cures the problem. If it does then maybe blame the tach.

edit: also unplug the blue wire near the alternator end and measure the voltage on it with key on. Should be 12 volts.

Mark

[davevickery]

[crazyvwvanman]

What about the fuel and temp gauges? The key-on power to the cluster also feeds those so if those for sure work when the light isn't coming on then that is one less thing it could be. But the alt warning light circuit is pretty simple so figuring this out shouldn't take too much effort.

I would try never to assume anything while troubleshooting. Test and measure, and try to write down what you see as you do it.

Mark

[davevickery]

Thanks, the temp gauge and gas work, so do the high beam, turn signal, and oil warning light comes on with with key on, just no alt light.

I did pull the tach connector and it made no difference.

I checked voltage on the blue wire at the connector in the junction box in the engine bay with key on. No voltage with key on but it seems to know it is connected to something because it moves around a bit from -.01 to .03 volts and back to zero when I remove the probe.

[crazyvwvanman]

The most likely place is a bad connection for the blue wire at the cluster 14 pin connector. That is pin 11 on a tach cluster. Pin 8 is a black wire that is 12v power into the cluster.


If you have the cluster out you can use a 9v battery like from a smoke alarm to test some of the cluster itself. If you put the battery + on pin 8 and battery minus on pin 11 the alt led should come on.

Mark

[davevickery]

Thanks again Mark, the foil looks good. I had previously checked continuity from pin 11 to the diode and it was good. And I checked continuity from the dash plug pin 11-blue wire all the way to the alternator plug using a long piece of wire and it was good.

Using a 9 volt battery, I got the turn signal (pin 10) to light up but not the alt light (pin 11). I also tried to light up the OX light (pin 14) even though it has never worked but it wouldn't come on either. So something seems to be preventing power getting to the Alt warning light.

I also tested the voltage of the cluster voltage regulator and it seems good at 9.94 volts per bently p. 90.18. BTW, when I tested the diode previously, it read around 600 whatever that means in the diode test mode of my multimeter and it out of range in the other direction so I figured that means it's good, but I don't what the 600 means.

[crazyvwvanman]

I just did the 9v battery test on a spare cluster and the alt led definitely lights up as I said.

There is a diode on the blue foil that prevents any possible back feeding of the cluster from the blue wire and I wonder if that is blown on yours.

Mark

[Guybrush]

Did you check if you have voltage at the LED? Maybe your LED is toast.

[davevickery]