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Topic: Instrument Cluster Illumination (Read 350 times) previous topic - next topic

Instrument Cluster Illumination

Hey everyone ,

1987 mercury cougar
full digital dash

Problem I'm having is the Instrument Cluster back lights do not light up during the day (well its very very dull)  unless the head light switch is on,

at night the Cluster is bright and normal with auto lamp working 

all other lights in car and external work,

i have replaced all the switches that have to do with the lights, dimmers and auto headlight , the auto sensors on the rear mirror and the one under the center dash hoping to fix the issue,

is there a relay i am missing ?

could it be a ignition switch problem starting or ...


Re: Instrument Cluster Illumination

Reply #1
With the headlight switch off:
The cluster LCDs should be on full brightness.
Powered through the ignition switch in Accessory or Run, fuse 6 and the normally closed contacts of the Cluster Illumination Relay.
The trunk release is also powered through Fuse 6. Does that work?

With the headlights on, the cluster LCD brightness is adjustable by the dimmer control.

Re: Instrument Cluster Illumination

Reply #2
More pics

Re: Instrument Cluster Illumination

Reply #3
yes i found the relay today after rechecking all the fuses, switches and bulbs in the cluster, i would rocker the headlight switch fast until i felt the relay that intermittently worked and replaced it

thank you for the info