Brazilian VDO combo gauge wiring

Can you post an engine photo concentrating on the left side of the motor area near the bottom left of the distributer? Normally the oil temp and oil pressure sensors are located there. I wonder if the previous owner used that sender just to join the two lines. 

In the top photo the multi-colored wire you circled feeds power to the gauge light. 

Thanks - it was the snipped brown wire I was baffled by in that pic, I’m good with the panel lights - they work fine! Ok - so here’s the ‘normal’ sender as requested. Just the one black wire from that..

Yeah that's your pressure. Should go to the green light I think.

That seems to be working - the light comes on on startup and then goes out a few seconds later..

The sender in your oil filter line is usually to turn on the fan assist on the external oil cooler.  The cooler (if installed) is probably mounted horizontally above the transaxle case in the void between the rear seat and the engine.  Never seen that used for the oil temp gauge, but then usually, where you show the oil pressure sender there is a T with two senders on it - one pressure and one temp.

Another place I’ve seen a temp sensor is in the middle of the oil sump on the bottom of the engine.  Not the greatest place, but it works.

I’ll post a diagram of the back of the gauges with what goes to each little tab tomorrow, for either a VS cluster or a VDO cluster - kinda late for me right now.

gn

OK, Tony:  Here you go.  There is a PDF attached to this with the wiring for a typical VS using the VDO knock-off Chinese gauges. 

Thanks so much, Gordon. So, first thing is I"m going to have to get a sump temperature sender - That's easy. Then as for wiring it to the gauge - the diagram shows +ve and sender wires both going to the same terminal - is that right? If it is, I'll do it!

Thanks again

Tony

No, there should be two separate terminals (1/4" fast-on tabs) at the top of the gauge, one above the other:

The top tab goes to the oil temp sender wire.
The lower tab goes to +12V switched from the ignition.

The Sender is a variable resistor to ground at the engine.

Most of us use an "L" fitting into the oil gallery right at the base of the distributor, rather than a sump sender.   Both will work equally well, but the sump sender is far less protected and could be damaged by road debris or simply bottoming out just right.

Here's a shot of my oil temp and oil pressure senders, looking in horizontally towards the passenger side, just below the distributor housing (Big gray thing upper right corner), Driver's side head cover to left (chromed), oil pressure at the Bottom and oil temp at the top.  If you peek at yours in the same spot you only have the pressure sender, so I don't know for sure where your temp sender is (or if there even is one).

Both the "L" fitting and sanders can be bought here.  Get a sender that goes to about 250ºF

http://vwparts.aircooled.net/VDO-Sending-Unit-T-Adapter-1-8-27-V240850-p/v240850.htm

I do prefer keeping the sender out of the way, so I think I’ll go for the fittings you describe, Gordon. And as for the gauge, I guess for my instance it’s the green one for the switched live (that’s the one going to the fuse box), the brown is presumably a ground, and then the new wire from the new switch would replace that black one that currently tandems across all the gauges..?

Tony, a few notes that may help.

I have a 2013 VS. The wiring mostly agrees with Gordon's diagram. The wire from the sensor to the gauge is dark green. (On my car, the wire for the oil pressure is light green - don't mix them up!).

It's common to daisy chain connections for power (+12V) or grounds from one gauge to another, but the gauge terminal that's wired to the sensor should have no other wires connected to it.

In the engine compartment, this dark green wire emerges from the wiring harness on the driver's side at the bottom of the compartment. Mine is bundled with a few other wires and zip-tied to the steel support rail that runs around the back and sides of the compartment.

I no longer have the original VS engine, and on my new engine we used a sump temp sensor, but I think the VS engine used a temp sensor near the distributor, as Gordon describes.

I think, in your photo of the gauge, you've pulled it out of the dash and are holding it so the gauge closest to the camera is the temp gauge. If so, that green wire should be the wire that goes to the sensor, and the other terminal on the gauge should get +12V.

You can test this theory by meausuring the voltages on the gauge terminals with a voltmeter, with the ignition on, to see which is 'hot' compared to ground.

Good luck.

That's not making sense to me, but I don't have a VS.

Anybody else  ( @Alan Merklin  got some better VS gauge wiring experience before I get this poor guy into trouble?  The sender at Aircooled should be OK, but his current gauge wiring sounds a little weird to me.

Each of the gauge functions has  a... +   a ….G ( gauge and the third shows a.... ground symbol. ( G on the gauge is not for ground) 

Thanks all. This is one of those things that you wonder why the previous owner didn’t fix... But, I’ll pull the gauge again, and hopefully I can ID the terminals as Alan describes, and then it should be fairly plain sailing... 

Once I get a sender of course.

Thanks again, and hopefully I can start contributing rather than questioning soon.

I like it when the lights are set up like this:

Green on the left for the Alt/Generator. Red on the right for NO oil pressure, meaning stop.

Easy to remember as G O, as in Generator, then Oil, left to right.

Both lights should be on on initial key on, then both go off when running(over 1000 rpm for the generator people).

Danny, I'm not that smart. Here's how I remember which is which:

Well, Mitch....  That’s a whole lot better than having a light come on and then think;

”Gee.....  My light is on.  Is that Alt or Oil?” 

And while you’re pondering that existential question, your crank bearings weld the crank to the case.   

Gordon, I actually believe one Cory Drake  told me about G O, years back.

Yeah Gordon, my thoughts exactly.

So I hate when new guys just leave a thread hanging with no conclusion. And although I don’t have a conclusion, I’ve found out a bit more about what’s happening oil-wise.

I got the T adapter and VDO sender as recommended by Gordon. I’m a little concerned that the length of the sender is such that it takes up about 60% of the cavity in the T - would that affect the pressure to the oil pressure sender? 
But before I fitted and tested it, I found that there is an oil cooler and fan above the transaxle. This explains that switch in the oil line to the remote filter. However, the fan is wired directly to the ignition switch, meaning it’s always on. And I have read all about overcooling at start-up. I just wonder why the PO would fit a sensor and then ignore it.. Further, I noticed what looks like a temperature sender plumbed in just downstream of the cooler - but this is not connected at all to anything. 
So - I will figure this lot out - at least I have all the parts! In the meantime it’s running well anyway, and I’ll update when I do figure it all out.

thanks!

Typically there is a thermal switch on the oil cooler on the outlet side that will turn on the oil cooler fan when temperatures get above 180 degrees or 190 degrees depending on which sensor you buy. The sensor will also turn off the cooler fan when the temperature gets to 170 degrees.

We don't always scan for dash warning lights so  a 12v buzzer or chime might be a cheap insurance policy.

I got the T adapter and VDO sender as recommended by Gordon. I’m a little concerned that the length of the sender is such that it takes up about 60% of the cavity in the T - would that affect the pressure to the oil pressure sender? 

No, but if it concerns you just wrap a little Teflon tape around the sender threads (2 - 4 turns pulled tight as you wind it on) and don't screw it in as far.  It'll be fine.

But before I fitted and tested it, I found that there is an oil cooler and fan above the transaxle.

Eureka!   That's the normal placement from Vintage.  Not the best place (that would be vertically in the driver's rear wheel well) but it works for a lot of people with less than 2 liter engines.

This explains that switch in the oil line to the remote filter. However, the fan is wired directly to the ignition switch, meaning it’s always on.  And I have read all about overcooling at start-up. I just wonder why the PO would fit a sensor and then ignore it.

Probably because the cooler switch died and the PO just figured "move the Ign wire from the switch directly to the fan so it'll be on whenever the engine is running and it'll be fine".

Further, I noticed what looks like a temperature sender plumbed in just downstream of the cooler - but this is not connected at all to anything.  

Well, that might be a good place to run the lead from the ignition switch that is currently going directly to the fan.  At least then it'll be switched on/off as needed, not all the time.

And Merklin, that's just what I did for our classy older friend, Ellie, when we lived in Beaufort.  She kept riding around with her blinker on a lot, so I went to a lot of trouble to wire in a Sonalert beeper gizmo in her car that gave an audible beep whenever a directional light was lit.  It wasn't til a little later that I discovered that Ellie was also as deaf as a Haddock.

Thanks again for the detailed advice. I’ll try shifting the wires around on the fan/switch, and also install that sender. And hope for the best. 
I’ll report back in due course..

Alan Merklin posted:

We don't always scan for dash warning lights so  a 12v buzzer or chime might be a cheap insurance policy.

I like the arrangement of the Pre-A warning lights.  A nice column of three lights that are very visible.

I just ran across a hand-written set of differences between original (steel) Pre-A and A models.  If you're interested I can either try scanning them or transcribe them for legibility.  I believe they came to me from Rich MacKoul - the '55 Speedstah Guy.

Interested?