1990 Audi 2309cc 20v Coupe Quattro - Page 3

sam · 20-02-11, 09:57 AM

Does the little green light light up? Or just the orange triangle? Did u check the pipe?

ksaudi · 20-02-11, 10:36 AM

Haven't seen green light. Where is it? Orange Triangle lit up. Haven't checked pipe yet.
Thanks
Keith

sam · 20-02-11, 12:48 PM

its in the centre of the diff on the switch... check the pipe!

ksaudi · 14-03-11, 05:55 PM

Now got mechanic with Audi experience to look at it and told him what you had said.
He managed to make Diff Lock work and Green Light come on (he messed with rear axle). I drove up to around 15 mph and Diff Lock disengaged as it should but I still could not switch it off or on with normal switch.
He has spent a few hours looking at the wiring as he is convinced that there is a short somewhere and also that the Oil Pressure Gauge problem (needle flying to max. when ignition on) is part of same fault.
He feels that I may wish to suffer it rather than run up a large bill for tracing it.
Do you or anyone else have any comments or ideas how we can trace the problem?
Thanks very much for giving it thought.
Keith

wildoliver · 14-03-11, 08:00 PM

I still maintain the oil pressure problem is just a broken sensor wire to the sensor. But if you do want those gauges I was keeping as spare I've decided to let them go.

If he fiddled with the back axle it suggests he operated the lever by hand, then the vacuum lock pulled it out as it should at 15mph. As the only diff locks I have played with are on the type 85 I'm working on at the moment you need someone to tell you whether vacuum/pressure is required to put in and throw out or part of the procedure involves a spring. I reckon you could be looking at a split pipe that is blowing out under pressure (and therefore not pushing lock in) but sealing under suction (and therefore pulling it out).

Really doesn't sound like a short somewhere to me.

ksaudi · 15-03-11, 11:47 AM

Oliver

Thanks for reply.

Gauge: Please confirm that you are thinking: Disconnect but leave old wire in place and thread new wire through - outside of loom etc? If so, do you have any tips on its route? Also is this a special Audi wire or can it be made up?
I managed to get some used gauges but, as everyone said, the gauge wasn't the problem.

Diff Lock: Very good news. Vac Pipe end under back seat was split. Cut off bad end and all now working, including both warning lights on switch and ABS warning on dash.

As always, sincere thanks to you and everyone else for help and, in particular, for diagnosing the Diff Lock pipe as the likely problem.

Keith

wildoliver · 15-03-11, 07:51 PM

No probs mate, if i can solve your oil pressure prob then 2 out of 2 would be nice!

Standard wire, I've made a few up now, nothing more elaborate than a spade terminal on one end and splice in to the gauge loom.

ksaudi · 16-03-11, 05:09 PM

Oliver
Thanks for that.
One more point: My guy says that other items (as well as Gauge) are on the same circuit/fuse and he thinks problem is probably nearer Gauge than Sender (perhaps between Loom and Gauge). He is happy to fit new wire but I think he is uncomfortable not finding the actual fault or knowing where to connect at Loom. I don't fully understand the problem as I naively thought cable merely went between Sender/Gauge.
Anyway, can you just tell me where you would try to connect at the Loom end and do you see any problem?
Sorry to be a nuisance.
Thanks very much.
Keith

wildoliver · 16-03-11, 09:02 PM

Not a nuisance at all mate. you literally do just need a connection between gauge and sender. Literally a straight piece of wire about a metre long. Your chap does seem to be making a meal of these problems, to be honest I suspect he's either out of his depth or stringing you along for labour!

The gauges are so simple, 3 wires on the oil gauges (2 on voltmeter but it works in much the same way) positive and negative (to power the gauge if you like) and then a sender wire which just runs straight to the sender (in a factory fit it won't of course and will go in to the loom, but ultimately will have nothing else inline so while it appears to go in to the loom it's still just a straight bit of wire.

The sender switches down to earth, no power to it, the gauge just reads the resistance to earth and displays accordingly.

ksaudi · 24-03-11, 05:11 PM

Thanks for very clear info.
Made up temporary cable and connected from Sender (big Sender near Rad) to Gauge to replace existing BL/W cable. Merely put spade connector on Sender end and pushed other bare end into connector on Gauge.
The Sender has another wire as well but not sure what that does.
Unfortunately Gauge needle still went to max. when ignition switched on.
Disconnected both cables at Sender but still went to max.
Tried another Gauge with same result.
Three different Gauges: Swopped plugs between Oil Pressure and Temp Gauges to see if power was making a difference but both Gauges acted the same, i.e. Pressure went to max. and Temp moved up slightly. At this point we did not have the temporary cable connected.
Are we doing something wrong? Is there any way of testing the 3 existing cables? Any other thoughts?
Thanks
Keith

20-02-11, 09:57 AM	#21
sam Grown up member Classic Audi Club Member Join Date: May 2008 Location: North east Posts: 778	Does the little green light light up? Or just the orange triangle? Did u check the pipe?

20-02-11, 10:36 AM	#22
ksaudi Grown up member Classic Audi Club Member Join Date: May 2010 Posts: 51	Haven't seen green light. Where is it? Orange Triangle lit up. Haven't checked pipe yet. Thanks Keith

20-02-11, 12:48 PM	#23
sam Grown up member Classic Audi Club Member Join Date: May 2008 Location: North east Posts: 778	its in the centre of the diff on the switch... check the pipe!

14-03-11, 05:55 PM	#24
ksaudi Grown up member Classic Audi Club Member Join Date: May 2010 Posts: 51	Now got mechanic with Audi experience to look at it and told him what you had said. He managed to make Diff Lock work and Green Light come on (he messed with rear axle). I drove up to around 15 mph and Diff Lock disengaged as it should but I still could not switch it off or on with normal switch. He has spent a few hours looking at the wiring as he is convinced that there is a short somewhere and also that the Oil Pressure Gauge problem (needle flying to max. when ignition on) is part of same fault. He feels that I may wish to suffer it rather than run up a large bill for tracing it. Do you or anyone else have any comments or ideas how we can trace the problem? Thanks very much for giving it thought. Keith

14-03-11, 08:00 PM	#25
wildoliver Grown up member Join Date: Feb 2009 Posts: 436	I still maintain the oil pressure problem is just a broken sensor wire to the sensor. But if you do want those gauges I was keeping as spare I've decided to let them go. If he fiddled with the back axle it suggests he operated the lever by hand, then the vacuum lock pulled it out as it should at 15mph. As the only diff locks I have played with are on the type 85 I'm working on at the moment you need someone to tell you whether vacuum/pressure is required to put in and throw out or part of the procedure involves a spring. I reckon you could be looking at a split pipe that is blowing out under pressure (and therefore not pushing lock in) but sealing under suction (and therefore pulling it out). Really doesn't sound like a short somewhere to me.

15-03-11, 11:47 AM	#26
ksaudi Grown up member Classic Audi Club Member Join Date: May 2010 Posts: 51	Oliver Thanks for reply. Gauge: Please confirm that you are thinking: Disconnect but leave old wire in place and thread new wire through - outside of loom etc? If so, do you have any tips on its route? Also is this a special Audi wire or can it be made up? I managed to get some used gauges but, as everyone said, the gauge wasn't the problem. Diff Lock: Very good news. Vac Pipe end under back seat was split. Cut off bad end and all now working, including both warning lights on switch and ABS warning on dash. As always, sincere thanks to you and everyone else for help and, in particular, for diagnosing the Diff Lock pipe as the likely problem. Keith

15-03-11, 07:51 PM	#27
wildoliver Grown up member Join Date: Feb 2009 Posts: 436	No probs mate, if i can solve your oil pressure prob then 2 out of 2 would be nice! Standard wire, I've made a few up now, nothing more elaborate than a spade terminal on one end and splice in to the gauge loom.

16-03-11, 05:09 PM	#28
ksaudi Grown up member Classic Audi Club Member Join Date: May 2010 Posts: 51	Oliver Thanks for that. One more point: My guy says that other items (as well as Gauge) are on the same circuit/fuse and he thinks problem is probably nearer Gauge than Sender (perhaps between Loom and Gauge). He is happy to fit new wire but I think he is uncomfortable not finding the actual fault or knowing where to connect at Loom. I don't fully understand the problem as I naively thought cable merely went between Sender/Gauge. Anyway, can you just tell me where you would try to connect at the Loom end and do you see any problem? Sorry to be a nuisance. Thanks very much. Keith

16-03-11, 09:02 PM	#29
wildoliver Grown up member Join Date: Feb 2009 Posts: 436	Not a nuisance at all mate. you literally do just need a connection between gauge and sender. Literally a straight piece of wire about a metre long. Your chap does seem to be making a meal of these problems, to be honest I suspect he's either out of his depth or stringing you along for labour! The gauges are so simple, 3 wires on the oil gauges (2 on voltmeter but it works in much the same way) positive and negative (to power the gauge if you like) and then a sender wire which just runs straight to the sender (in a factory fit it won't of course and will go in to the loom, but ultimately will have nothing else inline so while it appears to go in to the loom it's still just a straight bit of wire. The sender switches down to earth, no power to it, the gauge just reads the resistance to earth and displays accordingly.

24-03-11, 05:11 PM	#30
ksaudi Grown up member Classic Audi Club Member Join Date: May 2010 Posts: 51	Thanks for very clear info. Made up temporary cable and connected from Sender (big Sender near Rad) to Gauge to replace existing BL/W cable. Merely put spade connector on Sender end and pushed other bare end into connector on Gauge. The Sender has another wire as well but not sure what that does. Unfortunately Gauge needle still went to max. when ignition switched on. Disconnected both cables at Sender but still went to max. Tried another Gauge with same result. Three different Gauges: Swopped plugs between Oil Pressure and Temp Gauges to see if power was making a difference but both Gauges acted the same, i.e. Pressure went to max. and Temp moved up slightly. At this point we did not have the temporary cable connected. Are we doing something wrong? Is there any way of testing the 3 existing cables? Any other thoughts? Thanks Keith