a/t light flickering when hot/idling

[cd_photo]

Hey everyone,

Recently I've noticed that sometimes (not always) the a/t light will flicker when the van is hot and idling, I thought it might be a cooling system issue like a failing water pump or something, so I took it to my mechanic who looked it over, pressure tested the cooling system and said everything looks fine. He thought it might be the thermostat because the van also seems to be warming up a bit faster than normal according to the temp gauge.

It's a '94 L400 SWB.

Anyone have any experience with this?

Thanks,

Colin

[mark]

I have a 94 SWB L400, and am having similar troubles with my A/T light coming on. Usually happens when under heavier load (e.g., climbing moderate grade highway), but sometimes for no apparent reason (this morning came on when cruising at 40kph downhill).

AT fluid level appears fine.

[Big-Bird]

I have the full chassis electrical manual (thanks Cregan) which had a Russian language index...I just finished updating the index to english today and made it word searchable so I could locate the source of your concern...which could be my concern someday since I have an L400 too!

The wiring schematic points to an engine coolant temp sensor and/or switch which is part of the OD system and appears to be wired to the A/T light in the L400 instrument cluster. According to the schematic; the wire to trace is bright yellow for the switch. In order to find the OD Control box activate the OD switch on the gear shift level (on/off) so that the relay can be used to locate the control box.


The usual suspects: loose connection at the switch or control box, faulty/damaged wire, or switch/sensor is misbehaving/broken.

If you want the schematic image shoot me your email in a PM.

[cd_photo]

Thanks for taking the time to post this response Big-Bird! I don't think I have the mechanical capability to do this myself, but I'll mention it to my mechanic the next time I'm in and see if he can track down the problem

Best,

Colin

[Big-Bird]

I did some further checking: According to the Aussie club guys the AT dash light comes on when tranny fluid temps inside the gearbox are high (we know that part). They do have some recommended actions to address this in the attached photo but it's important to note that tranny fluid is pumped through a coolant transfer tank inside the lower tank of the radiator...If the coolant temp gets too high it can't carry excess heat away which could trigger the AT light as well. Your high temp issue may have more do with the coolant system..... I think your light flicker means the warning system is working right and that you have some checking to perform (see below)

image0-2.jpg (126.65 KiB) Viewed 2947 times

COOLANT SYSTEM CHECKS

• Check your radiator for dirt buildup between the cooling fins.
  Check your clutch fan for proper operation.
  Loose Belt tension on the water pump pulley and fan.
  Radiator has an internal blockage so less coolant is flowing through.
  A restriction of airflow through the rad. (big flood lights, paper, damaged cooling fins).
  Thermostat is faulty or the wrong temp range for the Delica L400.
  (Can't use a Pajero thermostat due to its higher temp range. Paj's have a thicker radiator than a Delica).
  Air trapped in the cooling system. (Remove the plastic breather cap for the cooling system which sits above the batteries next to the fresh air intake for the interior hvac system.)