2005 Prius Radiator Fan does not go into high speed

I have very similar symptoms in my 2006 Prius and have a clarification question.

At one point valde3 said: "Connect the pins 2 and 3 colors light green and white with black stripe and you should get the fans to full speed. It shouldn’t really matter which white with black stripe you connect the light green wire.

Disconnect the connector and bridge them from the front side.

If you then get the full speed, that you haven’t gotten when you should, you just need new pressure switch."

1. is this with the car running?
2 Please explain the second sentence? How is that different from the first?

Fred14

 

1. Yes car in ready. You disconnect the connector from the pressure sensor and bridge the light green to either of the white with black stripe.

2. It was just to clarify that you don’t need to cut the wires or do anything like that.

But now I would also add that when doing this don’t push anything thick into the connector that could cause it to loosen. So ether use test lead that has thin enough pins to push into the connector or just touch the front of the connector without pushing anything in far enough to loosen anything.

 

valde3
Thanks
Fred

 

For future reference I would like to point out my post 5, item 4 where I suggested the RDI fuse needed to be checked. This is relevant to the current discussion.

 

Patrick, valde3
You guys are great.
My 2006 has a fusible link. I was able to remove the clear plastic cover over multiple fusible links but could not clearly see if the link was broken as there is a center plastic bar. If it tests for continuity should that do it? If not any easy suggestions for removing it?
Fred14

 

If you can access that fuse then see if you can measure 12VDC from there to body ground.

 

Ok I think I need to start from the beginning. The 2006 Prius with 134,000 miles in Phoenix, belongs to my Niece. I bought it for her 3 years ago out of Nebraska. It has not been in any wrecks etc.

Niece says she thinks this problem first occurred after the Prius sat for 3 months in a garage this summer.

I was first told the A/C blew cool in the mornings but not afternoon when it was hot outside. I took it to an A/C place and they said the pressures were fine however it was only blowing 59 degrees and I would need a new compressor to have it run colder.

Niece and her mother were still complaining. I drove it to AutoZone one morning and it was blowing cool. On the way back it was definitely less cool.

I drove it to a tint shop on interstate. It does seem to start out cool for a little bit. I set it at Low Temp and High Fan. It was not cold. I drove it home, the same performance and when I got off interstate I set it to 70 Temp and High Fan. It turned cool. Not super cold but definitely cool.

I visually checked the condenser fan fuse and looks OK. I could not check the Radiator fan fusible link as my volt meter does not have long test leads to reach the link contacts.

Any thoughts on why it would turn cool when getting off interstate and setting the temperature higher?

Have not pulled and relays out yet. They seemed like a hard pull and did not know how to easily remove them.

I really hesitate taking it to a dealer. Does anyone have a suggestion as to why it would blow cooler when exiting the interstate and turning the temperature higher.

How does one know what fan is running and if it is in high or low?

Fred

 

Delete

 

Ghetto found this year that my tried and trusted AZ 06 wasn't cooling when sitting, other than for the first seconds when the High Speed Fan kicked in, and had strange lowest temp values when driving that were not very consistent, appears to have a bad Low/High Pressure Switch Connector and I guess overcharge.

I thought seemed to work funky when driving in regards to cooling rates and lowest temp achieved. Like I'd hit a bump and would start cooling at first when observed. Where-as another 08 with a fresher recharge from being low, drops to 45'F rather quickly when idle or driving. Albeit, that was a cooler day. Still, for example the AZ 06 min temp when driving is high 50'F's after a while and doesn't dip quick. Outside temps ~93'F to ~99'F. Again, lowest temp values and cooling rates seemed at times erratic.

I measured the pressures last night when Power On just started as well as idled and found when idle ~65-70psi on the Low Side and ~175psi on the High Side. High Speed Fan was not going on. AC Compressor was always on. Low Fan Speed for Condenser was always on. Outside temp ~93'F when measure.

30A RDI tested good, all fuses tested good, so decided to pull the Fan #1 B Relay Block with a lower mileage genuine Toyota that seems to test good. That didn't do anything. Decided to press in the wires to the Low/High Pressure Switch and viola, High Speed Fan turned on after a few second delay.

Temps for the first time in a while appear to be dropping in the cab, albeit slow. Guessing prior owner might have tried to recharge the system so is overfilled as well? Prior owner reported car went into a ditch on the passenger side. I do observe the wire harness tube cover pulled back more than in the prior image.

Thinking will need to deal with finding someone who can discharge-reclaim liquid and oil so can measure as well. I think I have the tools enough to complete the rest.

Will look for a good pigtail for the Low/High Pressure switch next or see if I can access the connector pins and recrimp-solder before hand as well as test to see if my Low/High Pressure Switch is good as noted in prior replies. I'll dig up the Service Manual and see what I can find.