1.6idi - Oil light - W terminal- battery light?

[meanvw]

Car is a 1983 Rabbit 1.6 non turbo.

I've been putting this car together from about 3 parts cars, and an older bentley manual.  (both of these things factoring in to my problems).  My manual only goes up to 81, and wiring diagrams only thru 1980.  Engine is bottom end Quantum turbo diesel, mechanical top end original to car -1983 rabbit LS.  



Motor is fresh, new rings, rods, mains, oil pump, re-did head, starts, runs drives terrific.  Been driving it for 2 days now.

Question is with the oil light.  Looked at Vince Waldon site, and just cannot figure out my deal here, doesn't make sense.

Question #1 is- Do I have my wiring right?
Should my car need - have- a W-terminal for alternator?  The alternator that is on the car which I believe is not working does have a W-terminal. I believe that the alternator is bad because after 2 days of use, the battery is now dead.  My instrument cluster does not have a tach- just a clock.  
Going to the W-terminal is a heavy gauge black/grey stripe wire with a heavy plastic connector end.

As for the high pressure sensor on the oil filter housing, this wire is a thin blue (solid blue/lighter gauge wire) with a heavy plastic connector end.  This blue wire and the black/Grey stripe are both in a little harness with the connectors for the shift light that go on the injection pump for a car with the shift light.

The sensor in the head has a white/black stripe wire going to it.  This wire also has the heavy black plastic connector on it.  In that cluster of wires, there is also a blue/yellow and a blue wire which are both hooked up to the coolant inlet in side of the head.

Question #2- What's the deal with this oil light?

When I switch the key on (not starting the engine) the oil light does NOT come on.  After the car starts, when the battery is at full charge the light remains off.  When the battery is going dead, the oil light starts to come on. I looked at Vince Waldon site and did a few searches here to diagnose.

Ignition ON, car not running, sensor in head is closed as confirmed by running test light from positive battery terminal to the sensor- light comes ON when ignition on/car not running.  Once car is running, same test of head sensor shows that once car is running, sensor opens as confirmed by test light positive battery to sensor yields test light off.  I think this is telling me I have oil pressure at the head.

Testing the sensor in the oil filter housing the same way, when ignition is on, engine not running, the high pressure sensor circuit is open, test light does not come on.  Start the car, and the test light to the filter sensor will come ON and stay on- even at idle.and stays on a second after engine is shut off.  I think this is telling me that I have oil pressure at the filter.

Those 2 things checking out that we do have oil pressure, light is still on, constant, no buzzer, not flashing


Question #3- What's the deal with this battery light?  How do I test the battery light?
Although the battery does not appear to be charging, the battery light does not ever come on.  It does not come on when the car is not running with the ignition switch turned on position.  The previous owner had an amp meter installed, and the wiring harness was all cobbled up.  The alternator I have on the car is the original alternator.  I used a different un-molested harness from a different car.  I pulled a the whole new harness - fuse box and all, If I recall correctly the car it came from was an 84.

Question #4 - Can I use this alternator?
I have an alternator that I was told was known to be good, and newly purchased by a guy that gave me a bunch of parts.  The case is stamped with a W, but there is no wire terminal to hook to, just a hole in the case.  I don't have this on the car, but will swap it in if the W terminal is something not needed or otherwise.



Thanks for reading and replying.

I do not need this car for transportation, but would like to figure out the problem if someone would be so kind to help.  I have time to work on the car this weekend, but a lot of stores are closed.  Things I already know:  I need to get a newer Bentley. An oil pressure gauge is in my future as soon as stores open up after the holiday weekend.  Autozone tests alternators and will have mine tested on tuesday.

I am pretty convinced that I've got some wires hooked up wrong the more I think about it.  But any help in the mean-time is appreciated.

[wdkingery]

i am of little help.

the W terminal juices the alt into charging. mine has one and it's hooked up. if you unhook the W, the battery light never comes on, and the alt likely never charges.

[meanvw]

Pics of electrical hook up at side of head- a blue, a blue yellow, and a yellow/black.  The blues have the type of ends that slide over the button type pins that are on the 2 coolant sensors.  The yellow/black looks at home on the oil sensor.



In this end of the harness you cannot see, but there is a black only wire that goes to the fuel cutoff switch on the injection pump.  There is the heavy gauge black/grey that I have going to the W-terminal, the thin blue that i have going to the oil filter pressure switch, and the 2 plugs not used that go to the injection pump sensors for the shift light switches

Just tried another instrument cluster, and does same thing as earlier described.

Also the guy who i got the alternator pictured from said he was running it on his 1.6l diesel motor.

[vanagonturbo]

i am of little help.

the W terminal juices the alt into charging.

This. Before you go throwing parts at it, you need to figure out why the battery light is not working. It is most likely a wiring problem and it should be troubleshot(?) before proceeding.

[meanvw]

So is the black/grey wire the correct W terminal "juicing" wire, and any ideas on trouble shooting the battery light.  My bentley has no reference to the battery light.

[Powered by Spearco]

The Alt pictured does not have a W terminal and the W terminal does not pwr. the Alt to start charging. Look at the square plug that has two big connection and one small. The two big ones got to the Bat. the small one goes to the cluster via the blue wire.

The oil light. In 1983,  the Rabbits started to use the dinamic oil system thats in the cluster, but yours is a separate relay.That relay to my knowleg is no longer available. Its what turns off the oil light in you cluster, taking into fact that your pressure switches are in good working order and they are the right PSI ranges at the right locations. They are'nt to much to replace.

Try this. Key on eng. off. Oil light should be on. Key on eng. on. Ground the cylinder head sensor wire to ground. The light should be on and or the buzzer should make noise. Rev it up to 2K RPM, buzzer should be buzzing. The filter housing switch should turn on the light if grounded when eng. running.

[vanagonturbo]

nevermind the W terminal at this point. I do not recall Murrican wiring colors off the top of my head, but I do know that the exciter wire for the alternator is the blue wire that is in the plug with the other two larger red wires. You need to troubleshoot the blue wire that goes to the battery light.

A quick test to see if the alternator just needs to be excited is to use a test light. Put the alligator clip on one of the battery terminals (I cant remember which one) and put the poky part through the insulation near the plug for the alternator on the blue wire. With the car not running and the test light connected properly (it will illuminate) the light should go out after you start it and rev over 1300 rpm. It will not hurt anything if you put the alligator clip part of the test light on the wrong battery terminal.

[meanvw]

I found part of bentley that said that in order to test the alternator wiring in the car that I wanted to check voltage at each of the red wires that connect to alternator.  Said that voltage to each of these wires should not vary from the voltage present between the terminals of the battery.  I think this would confirm that both the red wires are direct connect to battery.  That checked out.  13.4 volts... but and battery charging at 4 amps still (was dead). 
And then to test the blue wire in that alternator plug by jumper the blue wire to the negative battery terminal.  That was supposed to cause the battery light to come on... which it did. 

So then for grins I put in the other alternator that I had...  That alternator plugged in (excepting the W terminal) made the battery light come on when the car not running... but started car, and the battery light does not go off now.  So either more charging needed (try in the morning again) or alternator #2 is also dead.

[meanvw]

And update #2:

So I switch the wires for the 2 oil sensors.  The one that was on the head is now on the filter.  The one that was on the filter is now on the head... and it works.  Oil pressure light is on when car is turned on but not running.  Turns off right away when engine starts.

If I turn the engine off, and then put the key back into the "on" position without starting the motor again, the oil light is off for a second or 2, and then comes on.  I think the pressure at the oil filter has to drop enough to open the circuit again for the light to go on.

Upgrading to a gauge for sure so I can know where I am at.

Also need to get some alternators tested if I still have a battery light once the battery gets a full charge overnight.

By the way, where is the oil buzzer?  No matter what I do, never gets a buzzer.  Maybe this relay is missing/bad and causing this issue?

[vanagonturbo]

Sounds like you are well on your way to recovery.

WRT the alternator #2. did you rev the motor to see if the light would go out?

[Powered by Spearco]

Yeah, what he said ^.

[meanvw]

Swapped out alternator... one without W terminal.  Turn on car before starting engine, battery light on.  Blip throttle and it goes off and stays off.  My scirocco does this same thing, so I'm thinking this is atleast partially normal.

Swapping the wires to the 2 sensors also made the oil light work correctly.  A gauge is still in my future.  Went to only store open today (Autozone) and only oil gauge they carried was a sunpro, and it was mechanical/required running a little plastic tube through firewall to gauge.  Will look for something VDO.  Any suggestions?

Would also not mind having a volt gauge.  Will look for one of those too.  Hopefully Parts4vw's has all that.  Need some front brake rotors, and to change the fluid in the transmission and then we'll be ready for longer trips. 

[wolfsburged]

Find a Cabriolet in a junkyard, they came with a triple VDO gauge setup with volt meter, oil pressure, and oil temp. You can take the matching senders as well.

[R.O.R-2.0]

Find a Cabriolet in a junkyard, they came with a triple VDO gauge setup with volt meter, oil pressure, and oil temp. You can SHOULD take the matching senders as well.

[Quantum TD]

Just some info that I've gleaned over the years that may or may not help your situation (as it sounds like you're on track).

Wire Color Codes for USA Rabbit:
Temp Sensors: Blue with white stripe & Blue with yellow stripe. Doesn't matter which goes where
Oil Pressure: Blue with BLACK stripe to lower, White with Black to top
Fuel Solenoid: Black with loop end
W-Terminal: Thick black or black/gray with spade terminal on end.


On cars with the "Upshift" function, you may have problems with the Oil pressure light if the W-terminal wire is disconnected. This tends to appear when the car is warm and at low idle. The light may flicker or buzz. I'm not sure why this may happen, but I do know that the Upshift circuit and the oil pressure switch share the same wiring. So, if you get your oil light to come on in the ON position, and goes out with the car started, but comes on with the car hot and running, then look to the wire to the W-terminal