P38A - Minor (but irritating) issues

[donh54]

Getting ready to sell the Limo, and there's a couple of things have happened:

1. No aircon - there's always been a blend motor fault shows up on nanocom, but this time there's fans, etc but no cool air.

2. No cruise control - light comes on at the master switch, but nothing happens when you go to set the speed.

3. Drivers side window - always had a bit of a tight spot halfway up, now it gets to the point it will stop the motor. I'm going to pull the door card tomorrow and have a look.

Regarding 1 & 2 does anyone know of any common fuse/relay between these two?

[Keithy P38]

G’day mate,

#1 can sometimes be solved by replacing relay 6 and 7 in the fusebox, but you say you have blowers no worries, so I’m letting someone with more HEVAC experience take control of that one.

#2 have a look at the condition of the vacuum lines for the cruise unit in the engine bay, passenger side. They perish and then the unit can’t hold vacuum, thus no cruise.

#3 will likely be just a matter of securing the regulator bracket. From the factory they are riveted in, the rivers break and cause this issue (I currently have the same thing, I’ve found tilting the window backwards by hand as it goes up is a temporary fix).

Cheers
Keithy

[donh54]

G’day mate,

#1 can sometimes be solved by replacing relay 6 and 7 in the fusebox, but you say you have blowers no worries, so I’m letting someone with more HEVAC experience take control of that one.

#2 have a look at the condition of the vacuum lines for the cruise unit in the engine bay, passenger side. They perish and then the unit can’t hold vacuum, thus no cruise.

#3 will likely be just a matter of securing the regulator bracket. From the factory they are riveted in, the rivers break and cause this issue (I currently have the same thing, I’ve found tilting the window backwards by hand as it goes up is a temporary fix).

Cheers
Keithy

Thanks Kiethy, I'll give them a go in the morning

[redandy3575]

Getting ready to sell the Limo, and there's a couple of things have happened:

1. No aircon - there's always been a blend motor fault shows up on nanocom, but this time there's fans, etc but no cool air.

2. No cruise control - light comes on at the master switch, but nothing happens when you go to set the speed.

3. Drivers side window - always had a bit of a tight spot halfway up, now it gets to the point it will stop the motor. I'm going to pull the door card tomorrow and have a look.

Regarding 1 & 2 does anyone know of any common fuse/relay between these two?

Ok regarding number 1 the a/ c not working, i’d Start with the alternator!
because if you have weak voltage going in, the a/c clutch won’t engage. Usually a tell tale that the alternator is starting to fail. So do a voltage check and make sure it’s sitting above 14volts.

[prelude]

For the aircon:

Indeed check if the clutch engages. Check to see if there is pressure in the system (easiest way that will lose you a tiny bit of gas is just presseing the valve. You'd need to hear a good hiss. The system is filled with about 5 bar of gas so it should want to come out quite readily. Measure the voltage on the clutch wire to see if the car tries to engage it, maybe it is broken.

In general, an aircon always works/get's cold unless the pressure in the system is to high or low (to high only happens with extreme heat or blocked parts in a working system) or the clutch/pump has failed.

The cruise control:

The vacuum hoses are your first suspect indeed, you can operate the cruise control pump manually of you put power on the bottom connectors. Not sure which was which but you can run the motor and operate a valve. Just running the motor will produce just a faint vacuum, operating the valve will generate a good vacuum. Also, the brake pedal switch is connected to the vacuum. This switch is adjustable (you can pull it outwars) so it might have gone out of whack which will prevent a good vacuum of forming.

Lastly, the silver hella boxes (judgind by your MY I think you have one of these) are know to fail often, replacing them with a newer black version (you need the plug from a newer vehicle as well) is the way to go. The wiring is the same.

Cheers!

-P