Door Lock/Window DCM Relay problems - Symptom or problem?
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,363
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Door Lock/Window DCM Relay problems - Symptom or problem?
Just completed reading numerous threads on the typical Door Lock and/or Window operations being intermitent or non-operational.
Often it appears the fix is to either replace the relays on the DCM circuit board, or the whole DCM.
Obviously undersized/underrated relays could be both the symptom and the cause.
However, a voltage drop or poor ground connection could also be the cause, and both can be caused by undersized wire or poor connections.
Has anyone that has replaced either the DCM or relays, ever checked the DC positive Amperage AND the resistance of the negative ground?
Reason for question:
I have a decent knowledge/experience with electrical issues/problems, but thankfully we have not had any problems with our 2000 and only minimal with our 1994, but have had/helped lot of folks with Sailboat related DC electrical issues.
Nevertheless, in DC systems, the ground is as important as the positive side of the circuit and can cause similiar symptoms to power loss on the positive side.
I had an experience with our 1997 Lennox furnace's circuit board's relays failing annually (120 vAC). After the 4th board, it was time to look beyond the furnace guys to finally solve the problem.
After a Manufacturer's suggestion of checking the A/C common & safety ground, I discovering both were NOT done very well and were loose.
Since re-doing both ground wires, the circuit board has not failed for 4+ years (knock on wood) (and it was an identical board to the one that had failed the year before).
Therefore, I wondering if the relay problems on the C5's might just a symptom, with either a ground connection problem or undersized wiring actually being the cause.
Thoughts and any testing results might benefit everyone, and satisfy my curiosity and add a 'annual' maintenance item to all our lists.
Often it appears the fix is to either replace the relays on the DCM circuit board, or the whole DCM.
Obviously undersized/underrated relays could be both the symptom and the cause.
However, a voltage drop or poor ground connection could also be the cause, and both can be caused by undersized wire or poor connections.
Has anyone that has replaced either the DCM or relays, ever checked the DC positive Amperage AND the resistance of the negative ground?
Reason for question:
I have a decent knowledge/experience with electrical issues/problems, but thankfully we have not had any problems with our 2000 and only minimal with our 1994, but have had/helped lot of folks with Sailboat related DC electrical issues.
Nevertheless, in DC systems, the ground is as important as the positive side of the circuit and can cause similiar symptoms to power loss on the positive side.
I had an experience with our 1997 Lennox furnace's circuit board's relays failing annually (120 vAC). After the 4th board, it was time to look beyond the furnace guys to finally solve the problem.
After a Manufacturer's suggestion of checking the A/C common & safety ground, I discovering both were NOT done very well and were loose.
Since re-doing both ground wires, the circuit board has not failed for 4+ years (knock on wood) (and it was an identical board to the one that had failed the year before).
Therefore, I wondering if the relay problems on the C5's might just a symptom, with either a ground connection problem or undersized wiring actually being the cause.
Thoughts and any testing results might benefit everyone, and satisfy my curiosity and add a 'annual' maintenance item to all our lists.
