1990 Cherokee pre-heater function
Thread Starter
Member
Joined: Jun 2014
Posts: 110
Likes: 15
Year: 1990
Model: Cherokee
Engine: 4.0
1990 Cherokee pre-heater function
How does the pre-heater valve on the air box function?
Does the valve open on cold start up to draw air from the side of the air box rather than the front until it reaches some pre-defined temperature?
The reason why I ask is if I delete the pre-heater ducting will the valve always be open drawing air from the side of the air box?
Does the valve open on cold start up to draw air from the side of the air box rather than the front until it reaches some pre-defined temperature?
The reason why I ask is if I delete the pre-heater ducting will the valve always be open drawing air from the side of the air box?
Senior Member
Joined: Oct 2019
Posts: 789
Likes: 233
From: Current XJ is
Year: 95
Model: Cherokee (XJ)
Engine: 4.0
It improves cold engine idle, winter weather running and quickens warm up. Deleting the duct deletes the heated air. I forget at what temperature the vacuum switch flips the air door from the side to the front.
Thread
Thread Starter
Forum
Replies
Last Post
xjimmuisex
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
May 12, 2012 11:19 PM
cosmo11
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
Apr 1, 2011 04:20 AM
dyegunswin
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
Aug 5, 2009 11:16 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)