Gauges (factory) and warning lights except Speedometer/Odometer


deedu

New member
Hi,
I have an '87 2.1 Westy with a problematic temp gauge. I'm somewhat at my wit's end (and so is my VW-trained mechanic), so hoping that someone may be able to offer a new route or two to try. The high-temp light flashes a few times at startup, and then turns off as appropriate. The gauge starts out at the bottom, but as the engine warms up it goes up to 1/8"/almost to the top. And often (but not always, depending on how far I drive at what speeds) the flashing light comes on thereafter. And once it's on, it stays on until I turn the engine off. When I turn the engine on again (without allowing it to cool down) the flashing light generally goes through its start-up sequence and then turns off, which suggests that the engine is not overly-hot. I managed to get it into my mechanic during one of these episodes, and he had a lazer-gun temp-reading device, which he trained on the thermostat housing and close-by pipes, which showed temps of ~190-220, confirming that the engine was not overheated, despite the light still flashing.
We've done the following: 1) replaced the radiator and fan relay with it (the fan does come on and off as we speed up the engine, so that seems to be working) and bled/replaced the cooling system coolant; 2) replaced the sender unit; and 3) replaced the voltage regulator on the consul.
I've consulted the Bentley, my mechanic has printed out the wiring diagram (which I have and will gladly e-mail/fax to anyone) from ALLDATA - an expensive computerized system they pay $300+/month to subscribe to; and I've read through the earlier posts. Lorne Mathews' problem seemed closest to mine, but as far as I can see, there was no response to the issue he raised back in '02. If there is no solution to this, so be it. But I'm hoping someone might have confronted the problem with more success than we've had to date. Should I just conclude it's a faulty gauge, and order a new one? Or is there something obvious I'm overlooking? Thanks in advance for any thoughts/suggestions, as I want to address/fix this before the hot weather really arrives here in the Chicago area, as I don't want to fry my motor after getting too many "false positives/wolf-calls"!
 

icarus

Moderator
Question is,,, Is it an overheat light, or a low coolant light? When you say you have changed the sensor, are you talking about the coolant temp sensor or the coolant level sensor? If you haven't changed the latter I might suggest replacing the level sensor. Easy to do an not very expensive, just don't over tighten it!

Icarus
 

Capt. Mike

Moderator
First, you haven't stated you had the gauge checked via the procedure specified in the Bentley 90.21. Until this is done, everything else is speculative and you're wasting tech time.

The light comes on from two sources, tank overheat & low level. Remove each from the equation by disconnecting them per Bentley 97.109, circuits 65-70 and examine the results independent of each other.

Now go back to the basic principle behind the gauges. They work on changing resistance. The power goes through the gauge and only then to the sensor. The sensor has variable resistance based on temperature. In the case of the gauge, it goes through the sending unit and to ground. Notice the complexity of the ground circuit and possible signal contamination from the many others to that ground terminal. In addition to any resistance generated by the sender, resistance of wiring and sender-to-ground change the reading. Test those individual legs of wiring between terminals and connectors. They should have normal small wire resistance. If high or 0 ohms (grounding), they are sending false signal to the gauge.

Ditto the low level sensor circuit which has 2 components. The black magic behind the tank low level sensor is that the coolant can conduct minute amounts of electricity. Thus low coolant means there is nothing to conduct current between the probes and the now 'broken' circuit sends the failure light signal.

VW has established a set of test procedures for most components. They require the dealer to have the appropriate equipment to do so. Too many mechanics/shops (and I notice you're not using a dealer) won't invest in the publications or equipment so try to substitute. VW1301 is nothing more exotic than a variable resistance-inducing ohmmeter. A better shop will have one, whether "VW" brand or not (they are not made by VW -- the VW# just identifies them to the VW tool vendor). How much time (& time is money) and money are you investing when you don't start at page 1 -- the VW specified test?

With Raytek laser themometers now below $50, every wrench-turner should have one; see <TOOLS><Diagnostic Tools, electrical . . .>
 

deedu

New member
First, muchas gracias/many thanks to Icarus and Capt. Mike for their good advice. I sensed at least some frustration on their parts, which was multiplied at least 10-fold on this end, with this ordeal. But perseverance does (hopefully, at least temporarily) pay off in the end.
I forgot to mention that I early on took it to the local dealer, who determined it was a camper and thus couldn't be put up on their hoist, charged me $25, and told me they couldn't do anything with it.
Both of the mechanics I took the van to told me they didn't think it was overheating, but couldn't find anything wrong, as noted above, which would cause the gauge to read hot, having changed and tested the thermostat and both sensors as well as the voltage stabilizer. So, I contacted the guy who works on my computers and other electrical gizmos, thinking he will be able to make sense of this. He brought his ohm meter (I have one, but not confident in using it), and we checked the sensor, voltage stabilizer, and gauge - all seemed ok per Bentley, but the gauge still read hot and warning light on with idle in the driveway (and fan cycling on/off). Taking Icarus' comment on gauges (and sensors?) with variable readings, and the need to be able to check the relative reading on the gauge, we soldered a 15 ohm resister into the wire from the temp. sensor to the gauge. That brought the gauge down from 99%-to-the-top to slightly above the warning light, and no more flashing warning light, even at highway and just-off-highway driving. The gauge still works, and I'm assuming/hoping 15 ohms will not be enough to disable the warning function of the gauge and warning light. (Please inform me if I'm wrong in this assumption/hope!)

So, despite the fact that the temp. sensor unit was/is new, and checked ok with the ohm meter, it seems to have been the source of the problem?
What can be learned from this, of potential benefit to other westy owners? Keep looking until you find someone who is willing/able to help. Both of the Chicago-suburb VW mechanics recommended elsewhere on this site are at least 1 hour distant from me in normal traffic, and neither of the local, trained VW mechanics I found could come up with a diagnosis/solution. (And, maybe don't buy old Westies if your not in an area with many already, since otherwise mechanics/dealers don't want to mess with them!)
Thanks again Icarus and Capt. Mike - most helpful indeed! cheers, deedu
 

icarus

Moderator
I think that Capt. Mike was on the right track when he mentioned grounds. Look at the curcuit and see where the instrument grounds. I might suggest that you install a redundant ground for the gauge. As has been mentioned most accys use the ground to complete the circuit. A ground with too much resistance will/can cause all kinds of headaches. I had a problem with my dash lights, they caused the tach to go haywire, they brightened as I added loads, ie headlights, cigar lighter etc. It turns out that the dash cluster grounds were suspect and adding a redundant ground solved all the problems. Often it is easier to add a ground than it is to find and restore the original ground lugs.

It sounds like you are on the right track to a diagnosis with the resistor, but I think it is only masking the symptom. I agree that the car is not over heating.

Good luck,

Icarus

PS No frustration on my part. I may not always be right, but I often have an opinion!
 

Capt. Mike

Moderator
Troubleshooting the oil pressure warning light & buzzer, courtesy of Van-Again

How to troubleshoot the flashing Oil Light and Buzzer Syndrome on Vanagon 86-91

A common problem with 86-91 2.1l Vanagons is the flashing oil light with buzzer sounding. This article only effects 86-91 2.1l waterboxer Vanagons. If you have an earlier Vanagon (80-85) please refer to my previous article about the oil light coming on:
http://www.vanagain.com/flicker1.htm

Again, thanks to Ken Willard of Van-Again.
 

penton

New member
'78 fuel gauge and signal lights also not working. I suspect a basic wiring problem.

My '78 fuel gauge is also not working and there are problems with the signal lights and no back-up(reverse gear) lights. It started after some motor work. COuld it be simply wiring? short? or ground? too much resistance in ground? WOuld trying redundant grounds help? any ideas other than simply replacing the gauge? Thanks!
 
Last edited by a moderator:

thebigunit

New member
Location of fuel gauge sensor male post on tank

The fuel gauge stopped working on the 78 Westy we just bought. I took the dash out and made sure no fuses were popped or any wires had come un-done. I traced the wire from the fuel gauge in the dash to the passenger side rear tire, where I found a loose wire dangling. The only male post I see to attach the wire to is on the solenoid but pretty sure this is not the proper location. I tried it anyways for S & G's but after connecting, it did not fix the issue. I did notice that the wire has two cuts in it and a few of the copper strands are cut in each place.
Would this affect the voltage transfer once I find the proper post?

MAIN QUESTION: can anyone direct me to where I can attach this wire to its proper place? I have searched all around the area the wire can reach and have not been able to find any other place to attach it
 

DANALEXANDER

New member
oil temp and tach

Greetings from Portland,
Thanks to Capt. Mike and the various members who have posted to the cooling and gauge threads. I added a tachometer to our 82 Westfalia and a oil temperate gauge this winter and the information provided pays dividends in peace of mind. On a 2 hour trek to the Oregon coast last weekend the oil temp sat at 180 under load. The tach helps with shift points as I replaced the original speedometer unit, the odometer never worked, and the “new” unit does not have the shift points on the dial. In 2 weeks we will be going through the Mojave. Anxious to see what a 8 hour drive in 90 degree weather will register on the temp. gauge. I toyed with the idea of changing the dash unit with an water cooled unit like the one in my 84, but have no idea what problems would occur just to have a factory tachometer instead of a big clock! Cheers, Dan
 

vanis13

New member
LED testing

83 1/2 Westy water-cooled (and probably most others)

***checking LEDs in center of instrument panel (Oxy, Batt, Turn signal, etc.)

Bentley 90.5 Fig 6 (and corresponding pages for other years) says connect battery voltage to LEDs to check. After blowing out 2 of them, I realized that they are supplied with 10V from the voltage stabilizer – the thing I went in to check in the first place.

Better diagnostic is to switch one you suspect of being out into one of the sockets that you know works. LED's probably won't be burnt out so check the sensor delivering the signal.

I found this out 'cause I thought I'd check the oil LED when I had the inst cluster apart for another reason. My oil LED was not on with ignition turned on (pre-starter). Finally tested by grounding wire going to sensor. (FYI – later I realized easier to ground at wire connector on top of engine rather than getting at the sensor by removing the heat shield.)

*** how many oil pressure sensors should I have?

Can’t find a pic in Bentley of engine set up w/only one sensor like my vehicle appears to have. Bentley 17.7 Shows a 0.9bar sensor by oil pump – I don’t appear to have this one. I only have the one on the Driver side (ID’d as 0.3 bar) [Mod. note: Dynamic oil pressure sending system did not begin until MY 1986].

*** Voltage stabilier testing

Different to Bentley - my year (and all others) indicate the stabilizer center wire connected to something. In my instrument cluster only the outside wires are connected, the center wire is left bare. Doesn't seem to affect testing or operation.

Testing - Check a few times! first test showed within tolerance 10.15v. Later check, after partial run time at idle is showed <9v

Replacing - The stabilizer appears to be only a <$2 part from the local electronic store vs. $30 at dealer. Nice info along with substitute options at:

http://66.163.168.225/babelfish/translate_url_content?.intl=us&lp=de_en&trurl=http://www.t4-wiki.de/wiki/Spannungskonstanter

*** testing fuel and temp guage on pre 1985?

1) What resistance specs should one use to test temp gage on pre-1985 water-cooled?

Bentley covers temp gauge test only after 1985 (Bentley 90.21)

2) Since Pre 1985 doesn't correctly cover my vehicle (see #1), I'm wondering, with my year, do I use fuel gauge tests for pre-1985 or post 1985?

1980-1985 USA (Bentley 90.5) indicates 55=full, 560=empty, however after 1985 (Bentley 90.20) 50=full, 320=empty
 
Last edited by a moderator:

John_Pauline

New member
Voltage Stabilizer

Hi,
I have a 84 liquid cooled vanagon. I recently sent it in to the mechanics to do a tune up. Just before I sent it in the temp. gauge would spike when I started it up and stay there for a minute with the light blinking. I asked the mechanic to look at it and he ended up replacing the thermostat and sender (which cost me $600 because the bolts were seized). I got the car back and had the same problem. Back to the mechanic and he said it might be the gauge. I could borrow an new one from him but that did not work either. I checked the voltage stabilizer and got 3.5 volts from it so I replaced it. I still get the same reading. There are three prongs that come off the black chip on the voltage stabilizer. The outside two are connected to the circuit and the center one does not touch anything. The bently shows two prongs side by side. Any difference. Also, why would a new v. stab. still read at 3.5V when it should be 10V? Could there be something else wrong like the circuit itself?
 

zopa

New member
fuel gauge

Hi
I have a 77 westy...fuel gauge is wonky...will drop to empty at times...then back to full, or half full...is this a problem with the sender? anyone have any ideas?

thanks!
 

Vandogan

New member
Fuel Gauge problem

I have an 87 Westie. When the weather is cool or cold the fuel gauge does not respond after start-up. After some time it starts to respond. The length of time depends on how cold it is. Living in Minnesota, this is a common occurance. I suspect that the problem is a crack in the circuit board that makes when the board warms up. How difficult is it to replace one?
 
Last edited by a moderator:

Steve Williams

New member
Voltage Stabilizer Ghosts, Part II

Howdy John: I too have a little ghost like yours in my 84 West-Jestta. At start up the oil and ox sensor lights come on as well as the blinking coolant light. The coolant light goes out but the other two remain on until I increase engine speed. Then I hear a little "click", if you will and Oil/Ox lights go out.
The other odd thing is if I run with the headlights on the temperature indicator runs higher on the scale than with the lights off and the final part of this oddity is that the gas gauge shows minor fluctuations.
I have added upgrade headlights and relays but that "click'" is coming from the instrument cluster box.
Let me know how you fare.

Thanks, Steve
 

Mike Robinson

New member
Instrument problems

Multiple problems often mean single source, ie earth to the instrument cluster.

However, I don't know where the main earth is on the cluster - any ideas anyone.

Mike'82 Westy Diesel 1.9TD
 

Daddy Fantastic

New member
Oil pressure buzzer!!!

Hello, Can anyone help with a problem with my 86 Westfalia camper? The oil pressure light and buzzer come on intermittently while driving. Sometimes it is on only for a few seconds and sometimes it stays on for up to 4-5 minutes. the first time it came on was after my first oil change. (I bought the van at 276,000 and took it for an oil change pretty much right away) when I took it back to the mechanic he told me it was a faulty sensor which he replaced. this did not work so I brought it back again. He then changed the other (high pressure) sensor which also did not work. I have given up on him now. Sometimes I can bang the dash or wiggle the wire harness and the buzzing and light will stop which makes me think it is a wiring issue in the dash. I unhooked the harness and cleaned the contacts but still no luck. Since I took the cluster apart the instrument lights (3) also do not work all the time although wiggling the harness seems to fix this. I wouldn't mind disabling the buzzer if possible as my mechanic assures me that the engine is fine. Is it possible that he used the wrong oil filter when he changed my oil? I heard that might be a cause. Anyone had this similar problem?
 

papilio

New member
Newbie with oi/brake light hasssle

My wife drives a VW camper, the last of the air cooled. She knows every back track and one pub town in Australia. (I ride the BMW) Motor was rebuilt (just in case) by a known mech. But the oil and brake light have started to come on when stopping. Oil pressure check out. No one can come up with an answer. Has any one here knowledge of this problem. ppapilio@hotmail.com.au
 

adranq

New member
Hi
I have a 77 westy...fuel gauge is wonky...will drop to empty at times...then back to full, or half full...is this a problem with the sender? anyone have any ideas?

thanks!
Have the same issue with my 1975 VW Bus. Have you found any answers yet?
 

Top