After start up dash, windows, radio, seats not working properly

MICHAEL SAVAGE

MEMBER
2002 LINCOLN AVIATOR
43,000 MILES

No dash, radio, windows but everything will work if I turn the key to on without starting the engine. When I start the car I have everything working but for only a few seconds. Occasionally while driving everything comes back on but only for a short time. A mechanic told me the problem is in the dimmer switch, I replaced it and the headlights with no change.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

This could be a number of things but this sounds like a relay or circuit issue. What happens when you start the engine is there are additional components that come alive on the Junction boxes. This is different then what is on when you just turn the key on.

So I would check voltage on the two wires coming from the Battery junction box to the central junction box and make sure you have constant power.

Then we need to pick on of these systems (I would chose windows) and check for where we have power and where we don't. Start with the relay. Do we have power coming from the Accessory relay? If you look the cluster grounds the relay so we may just have an issue with the cluster causing all these other issues.

However, we will know this by finding out what power we have on the light blue/red wire and light blue/black wire.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Please see the diagrams below and let us know what you find with this.

Thanks

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