Fatguts

Righto so I'm working through the few problems that my cheapy '90 LS400 has, suspension sorted for now, AC regassed, headache stereo ditched in favour of a single DIN unit, now's time to sort out what's happening with the climate control unit.

Aside from the typical LCD bleedout, the power to the dash controls keeps cutting in and out randomly. At first it seemed like giving the four plugs a bit of a jiggle would solve it, and since two of the four plugs had broken connectors I figured the plugs weren't seating properly. But after closer inspection it doesn't seem to be the case. When it comes on it seems like it'll stay on until the ignition is turned off.

I'm starting to think that the unit itself has gone bad, the up/down temp button is half broken so I'm figuring I'll try and find one from a wreckers in the next day or so. But any first-hand info would be appreciated if anyone's had a similar problem.

LScowboyLS

does the Front Defog light blink 10 times? - this is the system going into reset.

UNCNOR

iTrader: (1)

Does the climate control unit give any other clues as to its functionality?

LScowboyLS

by the way, there is a diagnostic with error codes and everything for the climate control in the factory service manual, let me know if you need help running these diagnostic tests!

Fatguts

Thanks for the reply guys, greatly appreciated. To answer in order:

1. Nope, when it powers up there's no flashing LEDs, when it has power it works normally.

2. To be honest I hadn't bothered trying to pull any AC codes as my LCD has completely bled out, but I just went out to the car then to see what it'd do. Holding the auto and recirc buttons down when I turned the ignition on, the climate control unit powered up, all the LEDs blinked three times, then it started turning on and off, on and off, about six times, gradually staying on longer until it stayed on until I turned the ignition off. Then I couldn't get it to power up again no matter what I did. I'm definitely leaning towards getting ahold of a second-hand unit tomorrow and seeing if that fixes it.

One thing I noticed searching on ebay is they have different plugs - most seem to have three, some two, mine has four. I'm guessing mine has some extra functionality, anyone care to guess what it is, and whether different climate controls will work assuming the plugs fit?

python

iTrader: (4)

u have a bad head unit...mine did the same thing, got a new one on ebay for 50 dollars. urs will quit altogether soon

Fatguts

Cheers mate. Definitely going to try and find a replacement. No luck today, only wrecker that was open had two LS400s but both had different plugs on the back of the climate controls. Guess I'll just have to wait it out and find something when it comes up.

LScowboyLS

are you in Australia?

Fatguts

I am mate - Sydney.

Instigat0r

Same here and having the exact same problem with my newly acquired 1990 model.

Did you end up fixing it?