We've had a problem with our HHR for 2 weeks now. My husband drives over mountains for about 2 hours each way every night. He has lost power 2x going uphill to come home and it won't go past 50 mph. The abs, traction and svc service notices flash across the board and all the lights come on on the dash. They then turn off and it keeps going at 50 with the notices still on the screen. I've brought it to O’Reilly Auto Parts to pull the codes and nothing is stored in the system. I brought it to a mechanic friend the 1st time, and he said it was the alternator. Replaced it and now 2 weeks later to the day it did it again. What is going on?

 

Year and model might be helpful.
Check the large red wire connection to the under hood fuse box. Then follow that wire to the starter and check the connection there. Then that continues to the alternator. Check for a good non corroded connection and for 12 volts.

Check the fuse box itself by removing the cover and tightening the bolts you uncovered. Check that all of the fuses and relays are seated.

Check the inside fuse box; make sure the fuses and relays are seated.

Watch the coolant temp on the digital not analog. It should hover around 190-200 F.

 

Temp hovers around 170-180F. All connections look good. It's a 2011 LT with 96,000 miles on it.

 

You need a new thermostat, yours is stuck open. The t-stat's job is to keep the temp ABOVE 180F. Surprising you don't have any codes, like P0128 when you do the AC will stop working.

 

When you change the thermostat, get an AC Delco 131-158 180 degrees, and drain the coolant, then pour in fresh 50/50 Dexcool, it’s only good for 5 years.

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