Electrical?-Narrowing it down to the AP

[coralee]

I have narrowed down the problem with the flickering lights to when the Auto Pilot is on. It doesn't' matter if its engaged or not. When its powered up the LED lights flicker almost like strobes and when its off they work fine. Any ideas as to whether its wiring or in the AP itself?

Thanks for any help.

[jimcr]

Sounds like you have a voltage drop problem. how are the lights and Auto pilot wired in? Are they wired to the fuse panel directly or a connection away and together. Is the ground for the Auto pilot connected together with the AP ?

[highpointdf]

Sounds like there is a grounding issue somewhere.

[coralee]

I wired the lights into the existing line for lights thats original to the boat (1976) and with the AP being added a few years ago I believe it is separately wired. I'll have to do a little checking to see for sure. I could take and wire the lights temporarily directly to the battery and see what happens. I also know that most of the grounds on the boat ground to the engine block and not to the batteries is this correct? I did redo them to make sure they are clean with a good contact. When under power both batteries measure 13V. I do remember that when I hooked up the ground to the block it sparked.

[jimcr]

If your familiar with how to check voltage drops and have a probe,(basically your voltage should be the same on both sides of the load) it would make it easy but if not it may be like chasing your tail for a while. If you can run a new line for the lights at least a temp one you may find hat the old wire are corroded maybe even under the insulation , it only takes a pin hole to cause problems as moisture and electrical can make a mess.

If the runs of wire are not home runs back to the battery check there for problems. It sounds like the grounds run together or are back feeding to the lights.

As for the grounds going to the engine block , its not the preferred method but it will work , make sure you have a good ground between the engine block and the battery.

Corrosion will increase resistence ,heat and poor flow of electric.

Let me know if I can help more , just sorry I am in Milwaukee as this would be a fun one to fix.

Jim

[coralee]

Thanks Jim, I have a place to start. I'll run a temp line and see what happens.