Heater not coming on fully

[eurasiaoverland]

Hi All

I have a 96 Hilux Surf (JDM 4Runner). I'm not sure about the US Market models, but my Surf has an electronically actuated heater control, which does not fully open the heater valve on the firewall.

I've checked the cable, and it looks fine, it isn't getting hung up anywhere and is held correctly in place. The servo motor works.

I'm beginning to think that it's time to replace my heater valve.

Has anyone else had this problem?

Thanks

EO

 

[AntleredRuin]

When you say 'electronically actuated heater control', do you mean that you have the full digital screen, vs the knobs or dials? Not sure about the Hilux Surf (especially the 96 model) but I had a similar issue on my 99 Limited T4R with the digital climate control.

You're saying the server motor works? Did you check the white nylon gear in the servo? Those are known to strip and thus fail to fully open the heater flap. The nylon gear doesn't make a full spin, maybe only 90 degrees or so, so I was able to simply remove the gear and flip it 180 degrees so the non chewed-up end was making contact with the adjoining metal gear.

 

[jgue467]

...
I'm beginning to think that it's time to replace my heater valve.

Has anyone else had this problem? ...

Yes - my '01 had it replaced at 294K, works better now. Luck and enjoy the Runner. :cowboy:

 

[eurasiaoverland]

When you say 'electronically actuated heater control', do you mean that you have the full digital screen, vs the knobs or dials? Not sure about the Hilux Surf (especially the 96 model) but I had a similar issue on my 99 Limited T4R with the digital climate control.

You're saying the server motor works? Did you check the white nylon gear in the servo? Those are known to strip and thus fail to fully open the heater flap. The nylon gear doesn't make a full spin, maybe only 90 degrees or so, so I was able to simply remove the gear and flip it 180 degrees so the non chewed-up end was making contact with the adjoining metal gear.

Found my problem - the servo motor is fine (good tip to keep in mind though). The cable is stiff - the wound steel core musthave corroded slightly and becomes very stiff in the plastic shielding. The valve is perfectly fine.

I've got a new cable on order; if it is no longer in production (as a few less critical Surf-only parts have already been discontinued), I will trim back some of the plastic shielding and work some silicone spray lube into the cable. Interestingly, it seems to be the send of the cable which is in the cabin (not in the engine bay) which iscausing the problems.

Thanks!

EO