A couple of weeks ago I managed to fry the dashboard light circuit on the instrument cluster. Not that it wasn’t in sad shape already. I had patched various sections of the both the light circuit and the ground on the circuit sheet where the copper wiring was damaged. As a result, the need to replace the circuit sheet wasn’t a surprise, and I had been thinking about it for some time. I figured I could create a replacement wiring harness, using connectors from the original and sold 24 gauge wire instead of the plastic circuit sheet. First, though, I had to map out the circuit.
That took the longest, even with Bentley’s assistance. Eventually, using my digital camera, a lightbox, and Omnigraffle, I managed to create a circuit map which would serve as a guide for my new wiring harness
With that as my guide, I began using a DB25 connector and 24 AWG wire from Cat5e cable. The idea for using a DB25 connector came from a fellow Vanagon owner’s solution (link updated! Thanks Edward!). When complete, the new connector looked quite good. I was quite happy with my soldering.
Moving on, I used ring connectors for the fuel and temp gauges, and actually used the connectors to the tach, voltage regulator, clock, and oil pressure control unit by removing them from the original circuit sheet. This meant that I wouldn’t have to come up with adaptations in order to make the connections. On the original circuit sheet, there are a number of capacitors and resistors. These I decided to move to a circuit board, which I bought at Radio Shack. Finally, I soldered the lights (which I changed to LEDs) into the harness.
Overall, the result is quite good, and preliminary tests seem to indicate that I got the whole thing right. One thing I don’t like is that the dash lights are not easily serviceable. I may have to revise that to use some wire disconnects of some sort. For now, however, I can once again see my gauges at night.
ADDENDUM 03/08/2013
I’m clearly not alone in that I have received a number of requests to build something like this for other Vanagon owners. Unfortunately, while this is in concept a relatively simple wire-up, there are a number of complications which prevent me from being able to take on such projects at this time. First of all, I used parts from my old flexible circuit to manufacture the new wiring harness. I don’t have a stock of these parts, nor are many of them commercially available. Secondly, this isn’t a drop in solution, as I had to cut off the existing plug in the van to install the DB25. Unless you want to transport me directly to your house, you would have to do this yourself, and that requires a certain amount of wiring skills. There are other minor reasons why I can’t build these for others.So while it would give me great pleasure to help my fellow Vanagon owner out in this regard, I have to decline such offers.
I will happily answer any questions you have, should you decide to undertake this yourself. I am currently investigating the possibility of producing these commercially, but I cannot guarantee anything will come of that at this time. Thanks, and good luck.
-J
Here’s my somewhat similar attempt. http://staff.blueridge.edu/~edwardm/vanagon/pp023/index.htm
Beauty. Yours was the original that I “stole” the idea from. Thanks for posting the link.
Do you have a detail part list for this mod? My foil is in need of repair and I’d like to get rid of it all together.
I don’t have a specific part list. The following I bought at the local hardware store:
10ft of Cat5e cable
5 ring connectors
a box of assorted cable shrink wrap tubing thicknesses
From Radio Shack I bought:
Small (approx 2″x3″) circuit board
DB25 connectors (male and female)
Cases for the DB25 connectors)
solder
I also used 4 socket LEDs I bought from superbrightleds.com.
I built the whole thing pretty organically, starting with the DB25 connector, working to the circuit board, then the tach-side gauges, the idiot lights, and finally the speedo. I tended to cut wires longer than necessary to give myself lots of wiggle room, and cut things down as I worked on specific circuits. When all was said and done, it had 45 (I think) pieces of wire to make up the whole harness.
Many thanks for all this great information! I provisionally patched some torn foil circuitry and some of the circuits that were broken on the oil pressure warning board behind the speedometer with some careful soldering, layers of electrical tape, and some single strands of copper wire to “jump” the breaks. I still cannot see straight. This is by far superior. Can’t wait to try it.
The board and foil, for the record, were trashed by a careless mechanic who ensured me he could “fix” the oil pressure buzzer/light problems (which were, in fact, caused by him when he replaced the fuel lines and broke the lead from the low pressure sender). Admittedly, the lead on the engine was both old and brittle, and the PO hadn’t taken care of any of the wiring harness…but we’ve had some bad luck with local “Vanagon “experts,” to say the least.
Again, really impressive!
C
Thanks. Glad it was helpful. Sounds like my first repairs were like yours, until the whole thing degraded to the point of not working no matter what I did.
Three months post-repair and everything still works perfectly. At this point, the most likely fail point is with regards to the fact that I used solid wire instead of stranded, and that my ground might be a bit on the lightweight side.
The lack of knowledgable Vanagon folks is a problem around here as well. I try to do repairs myself when I can. To that extent I rely heavily on the Vanagon mailing list for access to people who know more than I do. And don’t even get me started with gripes about the PO. I could probably write a book with all the crazy stuff I’ve found done on my van alone!
This is awesome, thank you! I have an 87 syncro westy where the printed circuit is going. I would like to talk to you more about this and possibly solicit some help if you’d be so willing. Your work is pristine and indeed very impressive…send an email if you get a chance.
-Vip
vipgupta2008@yahoo.com
Thanks! If there’s anything I can do to help, let me know.
Just spent 3 days and 15 removals of my dash trying to glue and fix the little copper leads. Finally decided to replace any wire that went to a post on the cluster. Got the fuel gauge, the original problem, and the temp working at the cost of losing the tach.
Found your writeup by accident. Have already made a copy of the colored scheme.
What are all the resistors and diodes about.
Thanks this will be very helpful
Chris
The resistors match the circuits to their required voltages. There’s a section of the original foil that has the resistors on it, and I simply transferred what was there to the central circuit board.
Glad it’s helpful. If there’s anything I can do to help, let me know.
It’s possible that you can make one more same wiring harness for me??I will pay you what you ask.
Thanks
Jerry
I’ve privately emailed you about this since the response is kinda longish.
-J
I am interested in having you repair these for me on a regular basis. Could you please email me about this as a possibility. I have a Vanagon specialty shop and have been working on a selling parts for the Vanagon for about 14 years now. I would love to have someone I could call on to do this for me since this is such a problem right now.
Nice job, just found your blog from thesamba.com I have a 1989 Vanagon where I think I damaged the circut board around the speedo light attachment. I may have scrubbed this spot a little too hard to clean prior to replacing all my dash lights with LEDs (those little bulbs are hard to get in and out). Now no matter what light I put in the speedo housing, none of them work. How can I wire that light alone now to by pass the circuit board and get light into my speedo area? Any help would be appreciated.
Thanks for stopping by. The LED lights are very tight, aren’t they? I assume you’re aware that most the LED lights are polarized; that is, they’ll work one way, but not another. Sounds like that’s not your particular problem, but I made the mistake more than once of putting them in backwards.
I also had the circuit board around the lights get worn away, and before I made the new harness, I did a couple of temporary fixes. First, there’s adhesive copper foil you can buy. Look in the stained glass section of an arts and crafts store like Hobby Lobby. You might be able to patch things up well enough to get your lights working. It’s not an elegant or permanent fix, but it did last me for a while like that.
A more permanent method is to solder some wire leads directly to the bulb terminals, and then patch those into the circuit foil in some way. Ideally, you’d solder the leads to the circuit foil, but you have to be careful. Too much heat will melt it all and make a big mess. Practice the soldering a few times to get the technique down. You need to make a small solder point quickly. Once the joint cools, reinforce it mechanically with electrical tape or similar.
Good luck!
Could I hire you to build one of these for my 86 vanagon?
See the addendum at the end of the post, thanks.
Yeap…I fried my circuit foil while trying to replace a dash lightbulb. I am not an electrician. Does anyone out there know where I can get circuit foil for an ’84-’85 Vanagon instrument cluster?
You probably won’t find the foil separately. You sometimes can find the entire instrument cluster on eBay although they’re pricey. They also show up on theSamba.com classifieds, but tend to go quickly. Also note that when you do find a cluster for sale, the circuitry is not the same for all model years, although the sellers may not know this. I’m not sure which years share parts, other than 89-91 models.
The usual story I’m sure…..Just spent a $100 for another cluster assembly to get the ribbon. After working with it for a few days it turned out to be worse than my old ribbon. Came across your solution and if I can learn the soldering skills I am going to try it.
Nothing is worse than mucking with a bad cluster ribbon while at the same time trying to diagnose all the usual failures (quirks) of my dear vanagon. Just replacing a bulb can lead to total wreck of the ribbon with the in and out and that dumb 14 pin connect. Yeah, I’ve had with that bad engineering.
Thanks. If anyone gets up a thread to show their own progress please pass on the info if possible. I may lay it all out and then find someone who is an expert solderer and ask them to weld it up. Then maybe i’d just do the pig tail end in the van.
The soldering isn’t hard, and there’s plenty of how-to videos on the interwebs. Get a decent soldering iron, and spend a bit of time practicing with scrap wire. One key thing to remember is getting the surfaces clean.
Great job on the rewire of the cluster and the diagram. I’m working on doing the same thing but I’m going to use aftermarket tach and speedo. That leaves me with a problem of deleting allot of the cluster foil. My goal is to keep the center LED lights and move the red water temp LED to an open LED holder in the middle of the cluster. (Probably just keep the temp gauge circuit board and run wires to the LED)
I’m wondering if there will be any problems with cutting out wiring to the tach and speedo? I’m not sure how dependant they are to the other parts of the system, so I’m a little worried about cutting away. What do you think?
The wiring to the tach is only the field wire, which goes to the distributor. No other gauges depend on it. Check wiring diagrams as for what circuit path that is. As for the speedo, that’s all mechanical, so there’s no wiring to worry about there. The fuel gauge, water temp gauge, and oil pressure sending unit are going to be your real problems, in my opinion. Those are integrated into the tach housing, although they are separate wiring. You’ll have to extract those bits to make your system complete.
Good luck.
Hi- Thanks for the informative post.
I have a 1985 Wolfsburg weekender. The PO had replaced the instrument cluster for unknown reasons. When I purchased, it did not have a tach, but rather “the clock”. I believe from online research that it originally had a tach…..but I’m not 100% certain. I just purchased a very nice instrument cluster from a wrecked 1990, with a tach.
Before plugging in, I verified that he green wire was in the 9th position in the 14 pin harness. From what I have read (correct or not) the green wire is the tach, and that’s the slot it should be in. When I plugged everything back up, everything worked except the tach and the gas guage. (the gas gauge was not working prior to the swap, but I am about to recondition the tank and swap the sending unit, and i’ll debug that later) In order to investigate the Tach, I ran a wire from the connector at the coil up to the dash, and tested the green wire for continuity…..and it failed the test. I then tested from the coil connector to the small block with about 9 pins, about a foot away, and got continuity.
questions
1) how do you get a wire/pin to release from the 14 pin connector?
2) can I simply test the tach by running a wire directly from the coil (one side opposite the green wire is open) – thru the van, and straight wire it to the 14 pin connector? First as a test, but if successful…… a more permanent install somewhere underneath?
3) It seems odd to me that one wire would fail, just somewhere in the run. Is that likely? I wonder if anyone else has seen the green wire fail, and are there any likely locations where it is stressed? Or any other way to locate, then repair a break?
I’ve read “the kitchen sink” online, and can’t quite get the confidence to direct wire the tach. Your article is so well done, it’s easy to see you are a thoughtful and knowledgeable guy. Hope you don’t mind me asking!
Many thanks,
Bentley
Hi, sorry for the slow reply. I was out of the country when you commented, and I’ve been pretty lax about things blog-related this past month. Anyway, to answer your questions:
1. You can open up the connector housing if you carefully pry it apart at the clips. I recall using a jeweler’s screwdriver to do so. Just be careful, as I believe the pins are loose inside the connector, and they’ll all pop out once the connector housing is open. All the wires are terminated inside the harness by a crimp connector which would be difficult to reuse.
2. Yes, you can connect the tach directly to the field wire connector of the coil. Just make sure you connect the correct one. While you’re there, clean the contacts on your coil. That’s a common problem for tach-related issues.
3. Any of these wires can fail, and the likelihood only increases as the vehicles get older. Heat and freeze cycles, vibrations, bending, and age can all contribute to a potentiality for a wire to fail. The wiring in an automobile is stranded copper, so it’s fairly robust, but breaks do occur. Stress points are common at wire bends, terminal plugs, and passing through bulkheads or other sheet metal. Usually the best you can do to repair is to narrow down the problem to a particular wire segment. Hope this helps.
I am in the process of doing the same to my instrument cluster, but I do not have this piece:
http://www.kpcnsk.com/wp-content/uploads/2011/12/IMG_1873.jpg
What is it?
That’s the plug that connected the original flexible circuit to the Oil Pressure Control unit which lives on the back of the tach. I removed it from the foil circuit and soldered it up to my wiring harness. If you’ve got your old foil, look there.
Nice Job!!
Can you tell me the numbers of the resistors?
What number each color of the resistors is??
Thanks! I don’t know the specs on the resistors, as I used the existing ones from my old foil. I believe Bentley lists their resistances, but I’m not certain and don’t have the manual in front of me. I’ll look when I get a chance.
Also, could you post a photo of the back of your board?
I’ll need to check to see if I have one, otherwise it means disassembling things which try to do as little as possible. The plastic cluster housing itself is literally crumbling apart. The board itself is from RadioShack, and I use jumper wires to create the wire-up to match the diagram which is on the site. I could have used the wires themselves to directly connect to the resistors, but instead threaded the circuit through the board for stability. Not much to it, really.
If you should decide to take on the rewiring of these for other folks please let me know. I have one in failure. Thanks.
Hi. Between which colours on the drawing is there resisters? I see more soldering places on your card. But only 9 resisters. Want to try it myself. Has one with burned foil, that i want in my car. Jostein NORWAY
Good question. The diagram is an exact map of the wiring of the original flexible circuit, and I kept the arrangement of the resistors exactly the same. On the original, the top 9 circuit paths incorporate resistors. The second “point” from the bottom (orange in the diagram) is associated with the oil pressure control and warning light, and does not use a resistor. The bottom “point” (teal color in the diagram) is for the O2 light, which is only installed on California vans that I know of. Mine did not have a resistor here either, because I didn’t have an O2 warning light installed.
If you look closely at the picture of the card, you’ll notice that there are actually two wire sets (orange and white wires) at the bottom that don’t connect to a resistor. I could have eliminated these point entirely, when designing the circuit, but since this was my first attempt, I simply copied the original wiring wholesale.
Can you put the resistors and diodes on your circuit boardinto your omni graffle drawing? I am electronically inclined, but spacially disoriented 🙂
Thanks!
GoWesty announced that they’d be offering a product just like this in August 2013. Although I’ve been asking monthly, ever since, and they always say it’ll be released next month.
Are you working with GoWesty on this? Or, do you have the ability to reproduce this as a kit (yet, smile)?
Hi Jarrett,
I had a problem on my cluster and the wiring that led to it. Apparently it messed up the RPM feed (coming from the coil, green wire connected to T14-9). And the blue foil was damaged, so I decided to rewire the whole cluster like you did.
A thousand thanks for presenting your work on this page, I could not have done it without it. Actually I wouldn’t have thought myself possible of doing it. The pictures and the diagram were of invaluable help !
I posted a few pictures on a forum thread : http://www.thesamba.com/vw/forum/viewtopic.php?p=7798186#7798186. I’ll be glad to help people who want to do this. Don’t hesitate to contact me !
Awesome. Glad it was helpful.
I know this is an old thread, but I wonder if you remember a detail of the circuit for the Dynamic Oil Pressure System (DOPS) circuit. I’m attempting to make a PCB that would cater for connection to the DOPS PCB in the speedo, but my ’83 van does not have this feature.
Your circuit layout has been extremely helpful. What I cannot tell from your layout is whether there is actually a resistor in the foil between pin 13 (orange) and the pink traces that go to the DOPS and the Oil LED.
If there was no resistor it would mean that the DOPS PCB takes over completely the task of illuminating the LED – it would check for both the low pressure at idle (0.3bar switch) and the low pressure above 2000rpm (0.9bar switch) .
If the resistor is present, it would mean that the DOPS PCB only controls the LED above 2000rpm, and the 0.3bar switch that feeds pin 13 would separately control the LED at idle.
I suspect that the DOPS PCB in the speedo monitors both conditions, and therefore completely takes over the control of the LED. If not, there would be no reason for the 0.3bar switch to go to the DOPS PCB, as per your diagram.
So I’d like to know whether my PCB should include a way to switch that resistor in or out of the circuit depending whether the speedo has the DOPS function.
If you don’t recall this detail, do you have a photo of the resistors section of your original PCB?
Glad you found the diagram helpful. To answer your question, there was no component (resistor or diode) between the orange and pink traces. So you’re right, there’s no reason that the switch would need to go to the PCB. When I made my original wiring harness, my goal was to simply make the a replacement for the foil, so I copied the original foil layout pretty closely, and translated that to my perfboard.
Moments after I posted my question I realised you’d already answered it in an earlier reply – sorry! However, I did find some photos online of a brand new foil that had a DOPS connector AND a resistor in that slot. My guess is that the resistor may have been added back in in a later revision, to allow for the possibility that the DOPS board might fail. The 0.3 bar switch provides a route to earth for the oil pressure LED, so apart from a slightly higher current there’s probably no harm in there being two routes to earth – one through that resistor and one through the DOPS PCB. Nevertheless, I’m going to include a switch in my PCB to isolate that resistor, so that the board can be configured to match any original foil.
No worries. Good luck with your project!