Heater Question & Idiot Light Questions

[ZZ]

The heater in my truck is only blowing heat out at 116 degrees with the electronic controller set all the way over on warm and the engine running 184 degrees on a digital guage. Is there a linkage adjustment on the actuator motor for the temperature door or do I need to replace it?

The low coolant light stays on most of the time. I've checked the water level and it's always been full but the light will still be on. I have changed the sensor twice with no change.

The brake warning light came on Saturday night while I was running down the interstate and it has remained on since every time I drive it. This apparently started when the ECM fuse blew. I "think" this fuse is only for the glow plug relay and the overdrive on this '90 GMC but I could be wrong. I replaced the blown fuse but the brake light still won't go off. I had the brakes overhauled a couple of weeks ago and they seem to be as good as before the light started staying on.

[catmandoo]

pull the wire off the radiator low coolant switch and look inside at the little contact,mine was doing that also and if i wiggled it just right it would go out for a day or two but eventually come back on.what i did was just squeeze it with a pliers to tighten up the little loop inside so it fits the pin tight.as for the heater check right above the (gas) pedal there is a funky arm setup for the heater control motor i got in my truck one day and there it lay on the floor ,i thought what the heck is that so got looking around and the little plastic pieces that hold it together fell apart.

[ZZ]

Thanks for the response. I will check the connector for the coolant light.

Isn't the accuator by the pedal for the defrost/heat door? I think the temp door is in the middle of the box????

[catmandoo]

that could be .

[ZZ]

I took the box out today. There is no adjustment that I could find. I guess the linkage & etc is inside of the box. I did hear the motor run when I went from cold to hot and back.