I had a weird thing happen to my wife's daily driver. Thought I'd put it here and see what you gurus think. I may be giving more info than needed, but it may help.

Sunday, I took the family out for an overnight camping trip at Woods Canyon Lake near Payson/Heber. Her 2003 Chevy Trailblazer EXT (with 142,000 miles) has a 7 pin connector for the tow connection. I installed a 7pin to 4pin adapter so I can pull my M416 trailer.

We left at 6am from Glendale, AZ, where the elevation is 1300 and the morning temperature was around 80 degrees. We arrived at the Spillway Campgrounds near Woods Canyon Lake at 9am, where the elevation is 7500 and the temperature was around 78 degrees.

Here's where things got weird.

After I parked for 20mins at the General Store near the lake, I drove to the actual camp site. That's when I noticed that I lost Power Steering. I drove around for another 30mins and it never returned. During that 30mins, I was also maneuvering to back the trailer into the camp spot. PITA! It never returned. I checked the belts and they were good and tight. Fluids seem to be correct.

The Trailblazer stayed in that spot until we left Monday afternoon. I did start it up around 6am and let it idle til 7am, because I was trying to dry off the wet shoes and warm up the kids (we got hit with the monsoon rain from 3pm-midnight Sunday night and the tents got soaked even with the rain flys).

Monday, we left for home at 1pm. Stopped for lunch, and arrived back in Glendale around 5pm. The temp was around 109 degrees. I was all prepared to spend the next weekend changing out the Power Steering Pump.

When I pulled up to the house, I uncoupled the trailer and removed the 7pin to 4pin adapter. I then proceeded to drive and back the Trailblazer into my driveway, when I noticed that the Power Steering came back!?!?

Was it a coincidence that it came back when I removed the 7pin to 4pin adapter?
Was it a change in pressure due to the massive change in elevation?
Was it a change in temperature due to the massive change from 80 degrees to 109 degrees?
Could it be that that the power steering fluid level changed due to change in temperature or altitude?

My wife used the Trailblazer around 6:30pm to make run to Streets of New York for pizza. The Power Steering was still functioning.

This is odd!

It could be you over heated your PS fluid. Most likely need a bigger cooler. Has nothing to do with plug in.

Showboat wrote:It could be you over heated your PS fluid. Most likely need a bigger cooler. Has nothing to do with plug in.

The PS has a cooler?

I believe that vehicle has a steering rack. I'm unfamiliar with the symptoms you mentioned on this type of steering.

I agree with Geoff, it should not have any relation to the pin convertor.

Did it make any noise even slightly when the steering was out? Did the fluid level flucuate at all?

I know on some Honda's there is an o-ring that gets stiff :)) and restricts the flow of the power steering pump when cold. It's evident by a humming or whistle noise near the pump. There is a slight chance something similar is happening with yours.

long story short, that sounds weird, I only have guesses.

Nope. No sounds. PS was there, then it was gone, then it came back. Its odd!

Set up the same symptoms again on the weekend. Hook up the trailer and see if it mimics it.

defibvt wrote:Set up the same symptoms again on the weekend. Hook up the trailer and see if it mimics it.

Dang. I would have to drive back to Payson to mimick the conditions! Lol.

LOL..smart alleck.

2ndchance wrote:Dang. I would have to drive back to Payson to mimick the conditions! Lol.

And the problem with that is???

Is the power steering electronically controlled somehow? I know on newer vehicles a lot of the gas, brakes, etc. is no longer mechanically controlled, but "drive by wire". That would be the only remote possibility that connecting an electrical device like trailer connection could even effect steering.

K7VZ wrote:And the problem with that is???

Is the power steering electronically controlled somehow? I know on newer vehicles a lot of the gas, brakes, etc. is no longer mechanically controlled, but "drive by wire". That would be the only remote possibility that connecting an electrical device like trailer connection could even effect steering.

Kinda what I was thinking.

All good questions and I'm going to address them with a buddy of mine. Turns out he's a GM master mechanic. Who knew I had such good technical buddies! Thanks everyone.