check guages? cause??
#16
Senior Member
Join Date: Jan 2017
Location: usa
Posts: 799
Likes: 0
Received 4 Likes
on
4 Posts
Year: 2000
Model: Cherokee
Engine: 6 cylinder
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
CCKen wrote:
All the gauges in the cluster are fed by the CPU via the bus. Learn something new everyday. Thanks for that explanation.
Whats still puzzling is why all the connector contacts then? Must be the idiot lights, turn signal lights, etc. have got to be hard wired to their source switches and/or sensors.
The alternator voltage regulation function is in the PCM. The PCM sees the resultant voltage output of the alternator (and battery when the engine is not running). The PCM puts the voltage data on the CCD Bus. The instrument cluster pics up this CCD Bus data and converts it to linear voltage signals to drive the electromechanical voltmeter needle. The CCD Bus connection to the instrument cluster goes through two pins at the cluster. If one or more of these pins/bus data were corrupted all gauges would be affected.
Whats still puzzling is why all the connector contacts then? Must be the idiot lights, turn signal lights, etc. have got to be hard wired to their source switches and/or sensors.
#18
CF Veteran
Join Date: Aug 2010
Location: Canton, MI
Posts: 8,357
Likes: 0
Received 89 Likes
on
73 Posts
Year: 1999
Model: Cherokee
Engine: 4.0
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
CCKen wrote:
All the gauges in the cluster are fed by the CPU via the bus. Learn something new everyday. Thanks for that explanation.
Whats still puzzling is why all the connector contacts then? Must be the idiot lights, turn signal lights, etc. have got to be hard wired to their source switches and/or sensors.
All the gauges in the cluster are fed by the CPU via the bus. Learn something new everyday. Thanks for that explanation.
Whats still puzzling is why all the connector contacts then? Must be the idiot lights, turn signal lights, etc. have got to be hard wired to their source switches and/or sensors.
Here's the pin outs of the two instrument cluster connectors. You can see which hard wired cluster advisory lamps circuits go to the cluster.
![Name: 99%20instrument%20cluster%20pinouts.jpg
Views: 93
Size: 1.94 MB](https://www.cherokeeforum.com/attachments/f2/304918d1501203345-check-guages-cause-99-20instrument-20cluster-20pinouts.jpg)
.