Troubleshooting:
This
troubleshooting information applies to analog/HUD and SOHC/DOHC clusters.
There's not too much to it if you take your time and use your technical
skills. Measure all of the diodes in the back of cluster for basic
conductivity. If you find any that are shorten out, replace them. I used old
ones from an analog cluster I have for parts. The diodes are all the same in
the typical circuit of these clusters. Check the pics for the location of
the diodes. They handle the illumination of the cluster and clock. Also tied
up with the car light system. If you can find an FSM, look up the wiring
diagram. These two diodes are tied up on one side and by shorting out they
were grounding the lights on the car, also confusing the time control unit
and creating other issues. For example: headlight flip ups staying up and the ACC
function staying on.
A good look of the flex mat circuit board, BE CAREFUL
when handling this part, is very delicate. Also ensure that you maintain the
polarity of the diodes, they only go in one way and one way only. Your
soldering iron should be set to low or medium heat. The circuit pad is
extremely delicate and easy to burn if not careful.
An even closer look, not a perfect soldering job but
it will do. Also you might noticed that I soldered the diodes on the wrong
side of the board. Due to having to cut the replacement diodes from the spare
cluster, the diodes ended up being too short. But actually is better this
way, because if you need to replace them in the future you will not have to
take the circuit board and all light bulbs to have access to them. Just make
sure they don't touch any metal in the dash during or after installation.
After replacing the diodes, all issues were resolved. Ensure if you are also
using the HUD reflector that the connector to the HUD speedo LCD module is
on or you will not have cluster illumination. Verify that you have the
warning lights switch connected within the circuit or harness for your turn
signals to work properly. This will make your final testing go a lot easier
and smoother, instead of wondering if all of a sudden you have more faults
in the circuit.
