# 98 Lumina: system voltage unstable

**URL:** <https://community.cartalk.com/t/98-lumina-system-voltage-unstable/90550>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, lumina\
**Created:** [July 9, 2015, 4:03am UTC](https://community.cartalk.com/t/98-lumina-system-voltage-unstable/90550 "2015-07-09T04:03:50Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\
**Post date:** [July 16, 2015, 6:09pm UTC](https://community.cartalk.com/t/98-lumina-system-voltage-unstable/90550/21 "2015-07-16T18:09:51Z")

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The carbon deposits are material from the brushes as they wear.  
This is to be expected.  
But over a long life, 17+ years, the brushes have worn down, the springs that hold them against the commutator have weakened.  
This can increase heat and resistance.

[Previous page](https://community.cartalk.com/t/98-lumina-system-voltage-unstable/90550.md?page=1)