1993 cabriolet air/con inop . ideas please

timmyB4 · 15-10-13, 08:35 PM

Hi there , i have been told my 1993 cabriolet was a limited edition euro spec with cruise control/aircon . is this true ?? the cruise control is completely dead as a dodo . i know some other cars like the old pre 95 saab 900's, are a really tricky job to fix . How do i fair on my cabby ? thanks in advance. Tim

msh · 16-10-13, 02:50 AM

When you will finally forget about those damn saab's?

Your cab might be some limited edition, but I don't think it has to do with german market equipment, because B4's in germany didn't had much equipment either.

Presuming we're talking about cruise control [despite title of the thread saying otherwise] for the beginning check that there is cruise control pump and throttle actuator present in engine compartment together with connecting parts.

[the pump might be located in different place in RHD cars because of different battery location - I have no idea]

When you will confirm that we're talking about cruise control and you aren't missing any crucial parts, we could move on to electric and pneumatic stuff.

timmyB4 · 16-10-13, 08:09 AM

Thanks MSH , yes we are talking cruise control . And yes mine 100% stock with nothing missing on initial inspection . the vac pump for throttle is located in front of the ABS pump on RHD cars .

msh · 16-10-13, 04:58 PM

Ok, we can continue. See that second picture? That was test of pneumatic part of cruise control. As you can see, you need two wires to connect pump to battery, of course, with the plug unplugged, and some metallic object to connect power briefly to another contact. So, the pin on the pump, which has blue/red wire attached is pump motor, green/blue is pump valve and blue/red is common - what you has to do - first test both parts by connecting battery ground to common pin and try apply power to both other pins - valve, of course, should click and pump has small motor, so you understand what kind of sounds you should expect. In case if schematic used by me is different from your car, just use your wires and see what is what - pump is polarity insensitive, so nothing bad will happen in any wire combination - unless, of course, you will short your wires

Once you have found that your pump is fully working, attach in a way so that wires won't fall off, ground to common pin and power to valve, then use some metallic object to short valve and pump contacts to make pump work and see what happens. If the throttle opens and quickly closes when you remove power from pump [not the valve], get some pliers and clamp the hose that goes to interior and try again. If now throttle stays open, remove the shelf that is above drivers legs, both pedal switches are attached to pedal bracket - unplug the wires, unplug the hoses and screw them out. Carefully open them, clean contacts and everything, afterwards apply moderate amount of grease [yep, that's right - grease that stays viscous] on the part that closes hose and seat of that part. After putting the switch together, test it by sucking with your mouth. Also make sure they are adjusted correctly and there are no free play in pedals - after I put together my cruise control, it didn't worked until I found that my clutch pedal has free play so when I release it gently, it stays far enough to make switch keep open, so now, until I've solved the problem, I just pull back clutch pedal before engaging cruise control. After that's fine, you can test them again - long enough - I tested mine for hour [keeping the car with pump valve engaged with me absent, of course] and got zero throttle movements - in previous try I got throttle that got halfway closed after 10 minutes.

If the system keeps pressure but still cruise control do not work, we can move on to electric part. Ah, and in case if the pump does not work, it can be opened and sometimes fixed - I've pump in spare which spent several years in junkyard below open skies - I had only to open it and clean valve, which was stuck.

timmyB4 · 16-10-13, 07:40 PM

thank you very much for your detailed reply

. i shall report back . cheers

16-10-13, 02:50 AM	#2
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	When you will finally forget about those damn saab's? Your cab might be some limited edition, but I don't think it has to do with german market equipment, because B4's in germany didn't had much equipment either. Presuming we're talking about cruise control [despite title of the thread saying otherwise] for the beginning check that there is cruise control pump and throttle actuator present in engine compartment together with connecting parts. [the pump might be located in different place in RHD cars because of different battery location - I have no idea] When you will confirm that we're talking about cruise control and you aren't missing any crucial parts, we could move on to electric and pneumatic stuff.

16-10-13, 08:09 AM	#3
timmyB4 Grown up member Join Date: May 2013 Posts: 185	Thanks MSH , yes we are talking cruise control . And yes mine 100% stock with nothing missing on initial inspection . the vac pump for throttle is located in front of the ABS pump on RHD cars .

16-10-13, 04:58 PM	#4
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	Ok, we can continue. See that second picture? That was test of pneumatic part of cruise control. As you can see, you need two wires to connect pump to battery, of course, with the plug unplugged, and some metallic object to connect power briefly to another contact. So, the pin on the pump, which has blue/red wire attached is pump motor, green/blue is pump valve and blue/red is common - what you has to do - first test both parts by connecting battery ground to common pin and try apply power to both other pins - valve, of course, should click and pump has small motor, so you understand what kind of sounds you should expect. In case if schematic used by me is different from your car, just use your wires and see what is what - pump is polarity insensitive, so nothing bad will happen in any wire combination - unless, of course, you will short your wires Once you have found that your pump is fully working, attach in a way so that wires won't fall off, ground to common pin and power to valve, then use some metallic object to short valve and pump contacts to make pump work and see what happens. If the throttle opens and quickly closes when you remove power from pump [not the valve], get some pliers and clamp the hose that goes to interior and try again. If now throttle stays open, remove the shelf that is above drivers legs, both pedal switches are attached to pedal bracket - unplug the wires, unplug the hoses and screw them out. Carefully open them, clean contacts and everything, afterwards apply moderate amount of grease [yep, that's right - grease that stays viscous] on the part that closes hose and seat of that part. After putting the switch together, test it by sucking with your mouth. Also make sure they are adjusted correctly and there are no free play in pedals - after I put together my cruise control, it didn't worked until I found that my clutch pedal has free play so when I release it gently, it stays far enough to make switch keep open, so now, until I've solved the problem, I just pull back clutch pedal before engaging cruise control. After that's fine, you can test them again - long enough - I tested mine for hour [keeping the car with pump valve engaged with me absent, of course] and got zero throttle movements - in previous try I got throttle that got halfway closed after 10 minutes. If the system keeps pressure but still cruise control do not work, we can move on to electric part. Ah, and in case if the pump does not work, it can be opened and sometimes fixed - I've pump in spare which spent several years in junkyard below open skies - I had only to open it and clean valve, which was stuck.

16-10-13, 07:40 PM	#5
timmyB4 Grown up member Join Date: May 2013 Posts: 185	thank you very much for your detailed reply . i shall report back . cheers