Power cuts out randomly for 5-7 seconds

I have a 2003 Pontiac Vibe that was new to me in 2011. Pushing 180k+ miles. It was subject to the airbag recall last summer and has been repaired by the GM guys. But last fall I was driving at around 70mph with the cruise on and came up to a speed change so I tapped the brakes to end the cruise and EVERYTHING went dark in the car- radio, dashboard, a/c, the electrical charging plug- EVERYTHING for about 5-7 seconds. Then everything came back on and I continued as normal. My mechanic was dumbfounded. Figured one time freak thing so no worries. No issues since until this morning. On the drive to work I had the high beams on as it was 5:15 in the morning on a state highway in the country. Came up on a red light so flipped high beams off. EVERYTHING goes dark for 5-7 seconds, comes back on, and I continue as normal. Obviously I’m getting a little concerned at the randomness, not to mention that losing power at 70mph is a little disconcerting. Mechanic is dumbfounded but willing to tear up the dash and steering column and see if he can’t recreate the issue. Suggestions so as to minimize time and expense?

The 2005-2008 Vibes were recalled for bad solder joints in the engine control module that caused stalling. But you have an earlier model that wasn’t subject ot his recall.

But your ECM could have a similar defect. You could try swapping in a known good (used) ECM and see if that eliminates the problem. Another possibility would be a bad ignition switch.

Check the ground cable and connections from the battery to ground, Some GM systems only ground with a 10 mm bolt into the fender.

Is the cruise control and brights on the same stalk? If so I would think that more than a coincidence, and start there looking for problems.

The best way to find this might be to (at night) turn on lights, accessories, etc. Then wiggle battery cables and power feed wiring and see if things shut off or if you see any sparks at connection points, especially with grounds to the body, which would indicate where your poor connection lies.

It would also be worth getting a wiring diagram for your car so you can see what is common to all of the affected systems. I’m assuming that the engine never faltered when everything else went off, so we know it’s not a complete loss of electricity.

When you say “power cuts out” are you saying the engine continues running normally? When you said “losing power at 70 mph” I thought you meant losing engine power as well as losing dash lights.

GM has been force to recall cars of your era for bad ignition switch. Their fix until you get it serviced is only have the ignition key in. No other keys on a key ring. It has taken them 10 years and at least 13 deaths to admit there is a problem. I still don’t think they have admitted to every model affected. Try just using your ignition key and see if it helps.

@knfenimore, that recall did not include the Vibe, and it was for igntion switches that accidentally turned from “run” to “accessory” position, which doesn’t seem to be the OP’s problem.

The Vibe is more a Toyota than a GM car so I suspect it is not related to the bad ignition switch recall.