1996 Heater questions.
#1
11-21-2016, 01:01 PM
Join Date: Apr 2013
Location: near Portland OR
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1996 Heater questions.
My son has no heat in his '96 and I have found a lot of good information here. But I'm trying to get an idea on how the system works. The aux pump runs all the time (or when the engine is running or?) and I am trying to figure out the path of the coolant. If the aux pump is running all the time is the path of the coolant from the pump to the electric valve near the brake master and then on to the heater or?
We are getting hot coolant in some hoses, no vibration at the aux pump. Going back out to feel on some hoses right now to see where we have hot coolant and where is isn't so hot and trying to feel if the aux pump might be spinning or not! IF we have hot coolant to the pump (sure we do) but stops there it would have to be a pump problem, not running for brush problem or no power to it or clogged or ?. If we have hot coolant in and out of the pump then we see if we have coolant getting thru the valve...
We are thinking of going ahead and trying to get some brushes just in case...anybody have a stock number or physical size of the brushes so we can try the local hardware stores...had good look finding brushes at "good" hardware stores.
Thanks much!
We are getting hot coolant in some hoses, no vibration at the aux pump. Going back out to feel on some hoses right now to see where we have hot coolant and where is isn't so hot and trying to feel if the aux pump might be spinning or not! IF we have hot coolant to the pump (sure we do) but stops there it would have to be a pump problem, not running for brush problem or no power to it or clogged or ?. If we have hot coolant in and out of the pump then we see if we have coolant getting thru the valve...
We are thinking of going ahead and trying to get some brushes just in case...anybody have a stock number or physical size of the brushes so we can try the local hardware stores...had good look finding brushes at "good" hardware stores.
Thanks much!
Last edited by sanmigmike; 11-21-2016 at 01:45 PM.
#2
11-21-2016, 07:42 PM
Veteran Member
The idea with this system is a bit different, they attempted to maintain the heater core temperature closer to the demanded temperature, rather than full hot all the time. There is a vale that is PWM (pulse width modulated) controlled by the ECU. The amount of times it cycles determines how much coolant goes into the heater core. Due to the resistance of the vale, the pump ensures good circulation of coolant, and also can increase coolant flow and low engine RPM.
If you have no vibration at the pump, chances are the brushes are worn out. It's a cleaver arrangement, the impeller is magnetically driven, so you can remove the motor side and leave the coolant side attached and not leak any coolant. As a side note the screws that hold the motor together are Posidriv, not Phillips.
I'd just pull the motor out and measure what's left of the brushes. I did it a while ago, but I can't remember what the dimensions were.
If you have no vibration at the pump, chances are the brushes are worn out. It's a cleaver arrangement, the impeller is magnetically driven, so you can remove the motor side and leave the coolant side attached and not leak any coolant. As a side note the screws that hold the motor together are Posidriv, not Phillips.
I'd just pull the motor out and measure what's left of the brushes. I did it a while ago, but I can't remember what the dimensions were.