760 GLE 1990 B280E ECC (working, sometimes)

[diccapilly]

Hello all,

And Happy New Year.

The Electronic Climate Control, sometimes it works sometimes it does not and receive the flashing blue light - generally with a 133 diagnosis code but the code can vary.

I cleaned the sensor in the overhead dome light.

That fixed it for a few weeks.

The second thing I did was to solder dry joints in the vacuum controller.

That fixed it for a few weeks.

I am now wondering about the vacuum non-return values, there are two, inside the engine bay close to the firewall.

Could they be a red herring or could they be responsible for the intermittent problem?

Any thoughts, ideas most welcome.

Thank you.

[Laird Scooby]

Originally Posted by diccapilly

Hello all,

And Happy New Year.

The Electronic Climate Control, sometimes it works sometimes it does not and receive the flashing blue light - generally with a 133 diagnosis code but the code can vary.

I cleaned the sensor in the overhead dome light.

That fixed it for a few weeks.

The second thing I did was to solder dry joints in the vacuum controller.

That fixed it for a few weeks.

I am now wondering about the vacuum non-return values, there are two, inside the engine bay close to the firewall.

Could they be a red herring or could they be responsible for the intermittent problem?

Any thoughts, ideas most welcome.

Thank you.

The NRVs do fail, be warned, some are 10mm diameter so not easy to find but they are available. I had to replace mine for a similar reason and also that under load (accelerating or driving up a hill or similar) suddenly the airflow would cease from wherever it was meant to be coming from and little or nothing escaped into the car in the form of air.

I'll try and find an ebay link to the ones i used later, for now it's time to give the hound her daily constitutional!

[diccapilly]

Thanks Dave,

very much appreciated.

I've found this link

https://www.onlinecarparts.co.uk/oenumber/1228272.html

but I am unable to confirm the size until I get them out - they are probably the original set and are proving to be extremely stubborn.

Aargh.

[Laird Scooby]

As promised, ebay link to the NRV i used :

https://www.ebay.co.uk/itm/Non-Retur...e/272996189672

They have 6, 8, 10 and 12mm valves and they can be stripped down for cleaning/inspection.

Yes, they're a bit bigger than the OE valves and i would have added a pic but my internet is on a go-slow so can't find the pics i need to do that just now.

There is an arrow on them that should point towards the suction source (inlet manifold but take ito account there are T-pieces in the whole arrangement) but they're a "plug'n'play" job to change.

[diccapilly]

Hi Dave,

Thank you for supplying the link to the NRV replacements.

Much appreciated.

Regards

Steve

[diccapilly]

Hi,

Just to let you know.

I finally got them both NRV out and they are 12mm.

Regards

Steve

[Laird Scooby]

Originally Posted by diccapilly

Hi,

Just to let you know.

I finally got them both NRV out and they are 12mm.

Regards

Steve

Are you measuring the larger part of the barb or the base diameter of the stubs Steve? If that is the measurement on the outer/larger part of the barb, sorry to say it's not the size you need - you need to measure the base diameter of the stub which i strongly suspect will be 10mm.
You can also measure the bore of the hose they go into, this will probably be 10mm as well.

You can test the NRVs by blowing through them, one way should be fairly easy, the other way shouldn't let any air pass at all.
If either fail the test, replace both, one won't be far behind the other and both are likely to be 30+ years old at least.

PS - i just found a spare 10mm NRV, the base diameter is about 10mm the diameter of the barbs is just under 12mm so it stretches the 10mm hose slightly to grip on it.

[diccapilly]

Hello Dave,

Thank you for you latest post.

You are completely right regarding the measurements.

The stub and the hose diameter are 10mm and the

barb at the highest point is 12mm.

I have tested both NRVs and they seem to be operating as one would expect. Having prised them out I was hoping evidence would prove them (or one of them) to be the cause of the problem. I guess, maybe, they still, could be?

They are after all pretty old.

*
I've started to look elsewhere.

*
I'm wondering if maybe the problem might lie to the right of the whole arrangement, with one of the black rubber vacuum connectors?

There are three of them in total and they connect the black, white and greyish vacuum tubes to the firewall.

One of them which I think has the part number 1389628-7 is showing significant signs of wear.

It has a visible split but I do not think it has breached the wall completely so it should still maintain a vacuum but replacing it (them) would be the best.

[Laird Scooby]

Given that it's an intermittent problem Steve, i would first of all renew the NRVs and any associated tubing that looks less than perfect. Also check the brake servo hose for splits or perishing and the operation of the NRV valve in that, if fitted.

Going back to your earlier post with the fault code, 133 doesn't appear in the list of DTCs :

https://www.volvoclub.org.uk/faq/Hea...iagnosticCodes

Most likely is either 132 or 233, the former is either open circuit or short to +12V on the cabin temp sensor (in the courtey light) or more likely, the 233 fault which is the blower motor start current is too high.

I didn't realise how sluggish my blower motor was until it failed and i fitted a replacement (which i got from a late 940, had to swap the actual fans over and reverse the wiring polarity in the plug on the loom - can give full details if needed) and was amazed at the improvement in airflow. Was no fun having no heater just before Xmas as it was cold and damp so not only was i frozen but couldn't see where i was going!

If yours is like mine, it's fairly easy to remove - take out the underdash trim on the left hand side, the glovebox and then if yours is the same as mine, the motor will be mounted with the mounting plate vertical and facing you in the left hand end of the heater box.
Three screws secure it, they're fiddly to get at and have 8mm hex heads so an 8mm socket is the easiest. Unplug the rectangular electrical connector and pull/jiggle/twist until the fan motor assembly pops out into your hand.

You can squirt some oil in between the fan blades and the motor casing to lube that bearing, making sure it finds its way to the centre. With the plastic cover off the back end, you can esily see that bearing so you can dribble some oil onto that. Not too much in either case, you don't want oil getting into the motor and contaminating the brushes.

That may be the answer, if not as long as you've only done just enough oil to give the bearings a bit of lube, it won't do any harm.

Ideally you need to check the fault code that you're getting to be sure of what it actually is or you could be chasing your tail.

[diccapilly]

Hello Dave,

Thank you for your response.

I have removed the blower motor. It is a Delco. The rear of the unit is sealed so applying any lube there seems to be out of the question.

The fan does not have any access holes to the front bearings via holes in the fan and apart from the fins, it is a solid piece. Using two screwdrivers I could lever the fan up and off the motor spindle. That way I could get access to the bearings I think, in order to lube.

Dave, do you think that applying lube to the bearings might address this 233 error code?

Apologies, I mistakenly said 133, I should have said the diagnostic error code was 233. I must have got the 233 and 161 (Received that one too) confused.

I encountered another sensor. It looks similar to the one in the overhead courtesy light and was located just below the blower motor. It has benefitted from a thorough clean. I wonder might the sensor, having 30 years of dirt enveloping it have been the problem?