91 Vanagon -cranks, won't start- Dash RPM feed wiring fault

[jmranger]

I think I'd start by visually inspecting the PO's rewiring work. I guess he tried to bypass the old 14-pins connector, so his work should be 14 independent wires, running from the harness to the soldered points on the foil. Is it so? Anything loose?
I'm also surprised to still see the old female 14-pins connector, even if all wires appear cut. Is it still connected? If it is, any pins touching each other inside the connector?

[VicVan]

[Merian]

Some Vanagon Forensics:

You may already know this, but the presence of twist connectors on a motor vehicle means some PO has effed up your Van. Find them and replace with good properly done splices or connectors. Find the PO and kill him.

[jmranger]

I'm just thinking out loud here...
- It started suddenly, so it can't be that some wires were connected incorrectly in the PO's "restoration".
- The normal schematic of the cluster (that you linked to previously) shows that the tach signal doesn't interact with any of the components assembled on the foil. It just goes straight to the two connectors that you've disconnected previously. So it can't be that one of the components on the foil failed, unless it failed in a way that destroyed the foil around it.

I guess there are two options here:
- visually following that trace on the blue foil from one end to the other, trying to find something unexpected
- trying to confirm with a VOM whether it shorts with one of the other pins. But even if this is successful, you'll have to go back to the visual inspection to fix it.

I'm puzzled, but you're getting closer.

[VicVan]

[VicVan]

I'm back, a few days late. I changed the front calipers (seemed like a walk in the park compared to what we discussed in this thread). And here is what I've been doing for part of the weekend :

Work in progress...

More to come later today or tomorrow !
_________________
'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[VicVan]

Tada ! It works again !

So I redid the whole wiring of the instrument cluster, as well as cleaned the mess on the harness coming from the relay box to the instrument cluster.
I used this : http://www.kpcnsk.com/?p=138.
It took me more than two days, but know it all works pretty good !

Thank you all for your help. I feel happy now.

Some pictures
Instrument cluster with new wiring installed, along with 12-pin connector :

(the two grey plug-ins are temporary, I haven't received the led lights for the cluster yet, I'll solder them properly later)
I also got rid of the clock wire, I don't need a clock when I'm cruisin' in my van. And I don't like having things permanently connected to the battery neither.


Sorting out hings on the van side, only the connector housing is missing:

And with the female connector on, and cluster plugged in :

Boy does that look better than it used to... (if you don't remember, click here : http://www.thesamba.com/vw/forum/viewtopic.php?p=7781907#7781907)
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[kjono09]

Does your van run fine now? I have the same problem I think.
_________________
84 Retro-Westy GW 2.2L (Vincent)
67 Bug 2007cc (WBX in progress) (Davey)

Submariner

[VicVan]

Runs perfectly.
The only issue I have had since is the voltage regulator in the dash circuit that gave up. I changed it for a new one (sold 2 CAD at my local electronics shop). It's a pretty common failure, so I like to think it's not related to my work

If you have any questions please let me know! And don't forget: be patient.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[a2wolfsburggli]

I went with the Vanagon.org kit on mine. Works perfectly. Simple enough to do that my 9yo stepson helped me install it. Great instructions. Good price.

My only complaint is that the high beam indicator LED is FAR too bright. Their solution is to put a piece of hazed scotch tape over it or to spay it with window hazing spray / film.
_________________
Current: '87 Westfalia | '16 Audi Q5 3.0T S-Line w/sport package.

Past: '09 CC 3.6L 4motion "R36 wannabe" | '02 Audi TT "ALMS Edition" | '84 Jetta GLI with Autotech Supercharger | '89 Helios Jetta GLI 16v's (x2) | '95.5 URS6 | and the list goes on.

Never underestimate the entertainment value of OCD overruling Common Sense

[Steve M.]

Has anyone mentioned that if you installed a switch to ground out that green wire you would have installed a good anti-theft switch? 😁
_________________
This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[Vanagon Nut]

[DuncanS]

Too bright LED high beam--you need to put the little blue bezel that was originally in the dash over the LED. I did it and it toned it down. I used some blue LED strip for that so didn't need the plug. Alternatively, you can paint the bulb and practice with a bulb connected to the battery.

I have been reworking my instruments extensively and have soldered directly to the foil with no problems. The only things that need to be saved from the foil that I can determine are the voltage stabilizer for the fuel and temperature gauges: the chip with three leads right below the big phillips head screw. Note that the three tach leads are still plugged in.

and the dynamic oil pressure module attached to the speedo housing.

Here is the dynamic oil pressure module removed from the speedo.

All the blue tape is temporary to prevent shorts until I get to the end and will do a proper job of protection. The only connections I have left to the foil is for the gauges, tach and alternator and oil pressure warning lights. These will come off next. I have a spare foil to practice on, so I'm confident I won't crash and burn. Plan Z (I've found over the years Plans A through H sometimes aren't good enough and so always have a plan Z) in this case, buy a replacement. Since my dash is not stock, I plan to have the modified foil in a remote location permanently fixed so it won't need to be handled with instrument removal when accessing is needed.

Proof of concept photo.

In case anyone is curious, the LEDs from left to right are: red left turning signal, flashing red when inverter is on, alternator warning light, high beam warning between the fuel and water temperature gauges, oil pressure warning light, flashing red hand brake warning light, and green turning signal. Red for left and green for right as I'm a boater. It always bugged me that a single LED was supposed to tell you you were making a turn, but do I have the correct one?

And most important of all. Thanks so much, VicVan for the circuit diagram of the foil. You have done all the hard work for the rest of us. This will make my life so much easier as I would have gone blind trying to find out where the various leads went. It will help countless members. Will also get a PC board and do the resistors and so on. Thank you, thank you. Now I don't even need the foil at all in some remote location.

I would recommend that you start a new thread entitled Blue foil circuit diagram or what ever you want so it isn't buried in this topic which a whole bunch may not ever see. This is super important and needs to be shared to all. It should be a sticky

Duncan

[DuncanS]

[VicVan]

Your first picture (existing foil) shows 9 horizontal resistors (or whatever they are, let's call them components), and one vertically on the left. Total: 10 components.

Second picture (Printed diagram) shows 10 components stacked vertically.

You have to follow the lines, see which component is connected to what part of the cluster. They should be in the same order. Follow the circuit leaving the vertical component. It's hard to tell from the picture, but is it inseries with the first component of the board (the one on top)? However they are connected in the foil, replicate that on the board.

I used colored wire and triplde-checked everything, making sure the wires I made and connected had the same route than the ones on the foil. I bought some IT cable (can't remember the type, Ethernet or something else), that was actually composed of 10 or 12 internal wires, each in a different colour. Made it easier.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[DuncanS]

Here are two pics of both sides where the components live. If I have to follow the printed circuit paths on the foil to find out which is which, surely I will go blind and make mistakes. My plan tomorrow--later today, is to check for continuity which should make tracking them down much easier.

The three resistors in the first photo are all bonded together on one side which should aid in the ID.

And eight vertical stacked components in the second which is on the other side of the foil. The 3 in the first photo show on both sides of the foil so there are only 8 total. 6 resistors and two diodes. And on the left side next to the voltage regulator is what appears to be a good sized diode .

So 8 + 1 = 9. And yet the colored graphic shows 11. ??????????? Maybe 10 and 11 which are for the oil pressure unit are mounted some place else????????

If you number them from top to bottom starting at 1, the black--from the colored graphic--goes from the right of the voltage regulator to components 3, 7, 8 and 9. The center lead from the tach goes to component 1, which are all common and winds up at the 14 pin connector at number 3. Components 5, 10 and 11 go to pins 10, 13 and 14 respectively. The center lead from the voltage regulator goes to component #2 . And the top lead from the water temp gauge goes both to component 4, which is visible on the foil and therefore must be that big diode, and also to pin 6 on the connector according to the graphic.

The oil pressure control unit seems pretty straight forward once the components have been identified.

All this information should make life relatively easy providing it's correct.

Have I missed something here? Will this work?

Is there any reason why I can't just leave the components fastened to the foil and solder directly to their connections so the foil holds them in place. Once done, I would cut the foil away and epoxy a board to them to make it all more secure.

I've ordered the colored wire. 18 gauge which is probably overkill.

Thoughts?

Duncan

[crazyvwvanman]

If you look at the lower part of your blue foil photo you can see 2 metal dots.
Those dots are the locations 10 and 11 in the colored diagram.
Your van doesn't use 10 or 11 so VW left those spots blank on your blue foil.


The guy who did the colored diagram inserted a new #4 location and that shifted the rest down, so old #4 became #5, old #5 became #6, etc.
He moved that capacitor over from the voltage regulator into the new #4 spot. That is why his diagram shows 11 locations while your blue foil only has 10.

Mark

[DuncanS]

As always, Mark you knew the electrical answer to a question. I see now that the space I thought was 9 is actually the unused 10. 11 is at the bottom of the foil. That all makes sense as the two 10 ends seem to be just connectors for the oil pressure module and light. I'll run those wires directly from the 14 pin connector to the module and light.

I'm not using the turn signal light nor the O2 light so that saves some connections and eliminates the need for the resistor at the real #4.

I'm redrawing the diagram as there are unnecessary tortured current paths which are hard to follow and will post when completed. For example the super long pink and brown traces for the high beam indicator light are just a ground and a #2 connection at the 14 pin connector. That can be a stand alone to the left on the new diagram which won't need colors.

Duncan

P.S. To djkeev or a moderator/editor. This is all great stuff, but we have seriously hijacked the OPs topic, and no one will ever find it under the current topic name. All this should be saved and pasted on the end of the appropriate topic and perhaps become a sticky. Thanks.

[DuncanS]

Here is what I have boiled it down to. Very crude, but just asking for a check and then will clean it up.

As I said earlier, I'm not using the O2 light, dash lights, clock nor the turn signals so have deleted the components for them. Anyone with those could easily add them on.

Duncan

[chrisaj1]

Hi, I'm a new Samba member and first time owner of an old 1987 Vanagon and stating to discover all the "thrills" of the vanagon electrical/fuel system. I finally was able to pass emissions test and get it registered last week then attempted first trip which resulted in trailering it 90 miles back to to home. Here's what happened, it was running great, pulled into Fairplay, CO for lunch and it died pulling into parking space.
With key off: Noticed Batt and OXS lights were dimly glowing, Idle stabilizer was vibrating, had 5.8 volts across outer terminals of Hall sender plug on distributor, (that voltage went to zero with key on).
Other observations: Fuel pump not going on when key turned on (turns on when jumpered at relay or ecu cable)

Is this problem likely to be ignition switch problem or ECU or...?
PS not really sure how or where to post this.

Thanks in advance for all your expert help.
Chris