No gauges

[jkerem]

Hello everyone, long time lurker looking for some help. I’ve done some research and testing before coming here to post.

Quick back history. I just got this 1986 vanagon about 2weeks ago. Fairly good solid starting point of a van for what I want to do with it. The main issues I’ve been trying to figure out are the fuel and the coolant gauges are not working.

I may and jumped the gun and ordered a PCB cluster rebuild. I had high hopes that it was a cluster issue and after “rebuilding” I’d be good. Long story short not the case. Still no gauges. In fact since the install my rpm now pegs out with key on power.

So what I’ve done besides installing a PCB kit. I checked voltage at the 14pin connector. Going off the top of my head I believe pin 6 is red/yellow I’ve got ZERO volts with key on. I looked at the BLACK sensor at the back of the thermostat housing. The plug had some funky wiring and actual the plug broke when I was inspecting it. But from what I read was that if you jump the plug or in my case just looped the two wires together the temp needle should peg(hot). When I did that I got nothing so Im lost there and need to see if there is anything else that powers the cluster needle.

For the fuel side of things pin 7 purple/black wire also have ZERO volts with key on. This I just need to know could the fuel sender be bad? Does the sender send the power to the #7 pin at the connector?

Lastly the RPMs, like I said before rpms worked as they should prior. At the 14pin the tach is pin #9 green. At idle is reads about 4ish volts, give it gas and volts rise. At the plug for the PCB the board had 3 pins one is showing voltage that matches the 14pin connector, 1 is a ground, and one is constant. The second the constant lead makes a connection the needle pegs.

I’ve checked grounds. I pulled all the ground from the two crowns. I cleaned the ground leads and the crowns. I even tested the ground to make sure I had a good ground and went from the ground to the back of the cluster with no changes.

The company I got the cluster rebuild is being super helpful and is working with me as well.


Any info was be appreciated

[crazyvwvanman]

I think you may be understandably confused by the term "sender".

The voltage comes from the gauge and goes TO the "sender".

If the cluster 14 pin is unhooked then senders have no voltage.

Mark

[Steve M.]

crazyvwvanman correct me if I'm wrong!


it is a 12 volt system except that the fuel and coolant gauges work on 10 volts for some mysterious reason only known to the guy who designed it.

Look for this on the back of the blue foil just to see what it is.
https://www.vancafe.com/Vanagon-Voltage-Stabilizer-s/3304.htm

$39.00 for it is way over the top even if there is a chip shortage

it drops the 12v down to 10v and the Sambanistas can chime in where to find it cheaper!
_________________
This free advice is worth exactly what you paid for it.

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

[DanHoug]

[jkerem]

[Merian]

Do something easy that you need to do anyway:

pull the LH air vent cover out & shine a flashlight in there - you will see a whole bunch of wires clustered into a star shape.... one of the ground stars.

Pull them all off and clean really really well - electrical contact cleaner might be enough. Replace them. Even if that does not help this particular problem, it is good practice.

And BTW, you are in for a delightful discovery on the '86 - no, not the crumbling brown plastic. The lack of correct electrical schematics...
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....

[Steve M.]

[jkerem]

[jkerem]

[jkerem]

First picture is of my sensor. It looks melted, and there’s definitely 2 wire. 86-87 calls for a single wire sensor as seen in the second picture. 87+ call for a 2 wire sensor. However the orientation of the wires are different then what I’ve got. I looked at the date of my van and it’s a Jan/86 so it’s a true 86.