Dim Brake Light And No Cruise Control

[godpossessed]

Well it started with the brake warning light lighting the faintest you could imagine. The light has steadily gotten brighter and now my cruise won't set. You can turn the cruise control on, but it just won't take a set. The fluid level is fine. Could it be an e-brake switch adjustment? I don't even know if the e-brake will disengage the cruise if applied. Thoughts?

Mark

[wwest]

Well it started with the brake warning light lighting the faintest you could imagine. The light has steadily gotten brighter and now my cruise won't set. You can turn the cruise control on, but it just won't take a set. The fluid level is fine. Could it be an e-brake switch adjustment? I don't even know if the e-brake will disengage the cruise if applied. Thoughts?

Mark

If your rear brake lights are not FULLY functional cruise control is disabled.

The system "measures" the electrical current flow in two circuits, the high mount brake light, and the standard brake light parallel "string" and if it isn't up to a predetermined level you get the failure icon and the cruise control is disabled.

[glenmore]

My shot in the dark would be your alternator. Mine failed about 150m. In hindsight my parking brake light was doing strange things. It would fade a little after I released the parking brake but would remain faintly lit. Brake fluid level was fine. Then all lights went on but the one I didn't pay attention to was the battery charging light. The battery drained to zero. Got a new battery but charging light was still on and then a new rebuilt alternator solved everything.

glenmore

1991 300CE

1990 LS400

2000 C280

[wwest]

Have someone apply the brakes while you watch to see if ALL the brake light bulbs are working and fully bright, including the high mount. If not then replace bulbs and retest. If all bulbs are working then look for a bad ground/body connection on the bulb failure detection module.