These are one piece that wraps down and includes the turn signal. Just watched a youtube video and it looks pretty easy to replace them.
Headlight assemblies are both yellowed and hazy. I wet sanded and then buffed a pair years ago but had to repeat the buffing on occasion because there was no longer UV protection.
Check Engine light was on so I checked the codes and it had O2 sensor code and cooling fan 1 circuit. Looked under the hood and saw a regular clutch fan that's bolted to and spins with the waterpump. No electric fan(s). Searched a trailblazer discussion forum and found out it has a hybrid fan. Electronic version of the clutch fan.
The temp sensor remains stationary while the clutch with fan bolted to it spin. In my repair software, I saw a TSB that says the wires can chafe inside the plastic tubing and create an issue so I'll look into that but I'm tempted to just replace it. There must be some little bearing in there to allow it to not spin while the clutch does. If it's original, that bearing's 20 years old with 192,000 miles. If that bearing ever froze or fell apart, it's apt to sling around and punch holes in the radiator.
Not cheap though and you can't buy just the sensor. Can only get it as pictured. No name China, $80 - US Motorworks, $140 - Hayden, $170 - Genuine GM, $200.
US Motorworks is a newcomer but the waterpump with fan clutch of theirs that I got for the truck seemed good quality, Hayden has been around a long time or for $200, get the OEM GM part and be good for another 20 years. They were only used on Trailblazer/Envoy 4.2 liter which were only made for 6-7 years so someday, those fan clutches will be hard to find.
I'm going to unbolt the radiator shroud and slide it back so I can reach the sensor. See if it wobbles at all and see if there's anything I can do with the wires without cutting them to pull them out of the tubing. Looking at all the pics of the different brand names, I don't see a slit in the tubing like wire loom has. About all I'll be able to do is wiggle it while checking continuity between wires and from one end of a single wire to the other end. For that matter, I can check to make sure the fan clutch doesn't wobble because that's definitely a radiator killer if it comes loose.
The code P0480 means the computer is commanding the fan to engage but not seeing a return signal verifying that is has. I know the fan engages because it's loud when it does. Seems to come on at weird times though. Had it come on one morning when I had just barely made it out of the driveway and the engine wasn't even at full temp yet. Have also had it disengage when it was hot out and I had turned on the AC a minute earlier. Seems like a short or bad sensor.
Got my two new tires put on the front yesterday and was going to order the other two tomorrow morning but might be getting a fan clutch and O2 sensor instead. Back tires aren't bald and can wait a while. Just need to replace them before winter weather kicks in. Same with the headlights. I can see just fine but would see better with clear lenses and it would make it look a whole lot better.
O2 sensor is the upstream sensor meaning pre-catalytic converter. In this case, it screws into the exhaust manifold. It's more expensive than the downstream of course. $50 for Delphi/Bosch or $80 for Genuine GM so I might was well spend the extra $30. Wouldn't hurt to get the downstream as well and have them both reading right. Probably pay for themselves in improved fuel mileage. It has a shudder when maintaining a speed. Give it a tiny bit of gas or take foot off accelerator and it goes away. Makes cruise control kind of useless and makes me either be accelerating or decelerating all the time. The O2 sensor(s) will probably fix that. Just looked again and GM downstream is also $80 and both sensors in Bosch would be $80 so I might get Bosch.
Gonna pull a spark plug or two and see what those look like. Air filter looks good. Fuel filter has probably never been replaced. Need to do an oil change and tranny filter/fluid change. Need to drain a little coolant and see what color it is. It's too low in the expansion tank to see it. If it has the orange GM coolant, I'll get that. If it's green, I'll get that. Hate to mix them. Not a fan of the orange GM stuff because it looks like rusty water so hopefully it's been swapped over to green. Draining a little will also allow me to check the strength.
All these parts are adding up so I'm getting a little less picky about the brand and more concerned with price as I go. It is a 20 year old rig with 200k on it after all. Fan clutch I'll do GM but everything else is likely getting downgraded but not to no-name China. Why get top of the line headlight assemblies when I drive a critter crowded road every morning at 4:30? I've seen well over a dozen deer in one spot on that road. Been t-boned by a few. Nothing like driving at 4am and having something slam into the driver's door at 30-40 mph. They hit me more often than I hit them and new headlights and extra bright bulbs will help reduce me hitting them. Next cool spell we have, they'll be out in large numbers.
Need to build a heavy duty brush guard type of thing -- A DEERFLECTOR Most of the ones you can buy are pretty thin metal. Not much help when you're going 50-60 mph and hit a 300 lb deer.
- Fan Clutch
- O2 Sensors
- Tires (x2)
- Liftgate Cylinders
- Headlight Assemblies
- Right Taillight Assembly (was cracked when I bought it)
- Headlight Bulbs
- Oil and Filter
- Tranny Fluid and Filter
- Spark Plugs - maybe
- Coolant
- Windshield Washer Fluid
- Wiper Blades (x3)
Looks like the next 2-3 paychecks are going into the Trailblazer. Needs to be right for winter. That pushes high tunnel spending out to the first of November.
Speaking of November, yes that map does seem a bit off. Has this area in full color well into November when in reality, everything will be brown by then.