Towing... 4 to 7 pin w/brake controller for electric brakes?

I'm only replying because I think you're likely to get few replies. The particulars of my experience might not be a good match.

I installed a Tekonsha 4-wire kit on my Prius c. The kit was labeled for a c, but in fact was meant for the regular Prius. Everything was the wrong length for my car and I wound up having to hack it up and rebuild it as the manufacturer was utterly clueless- and that's sad, because Tekonsha is a leading name in tow equipment.

Anyway, their kit would fit a regular Prius like yours for a 4-wire application, and they do it properly with transformer isolation on all the lines and an independent controller.

In my case I had no trouble installing the actual control module in the same general area as the 12v battery in the back of the car, and it works perfectly. Obviously for a 7-wire setup, you'll also need to run wires forward to the dashboard for the override controller/accelerometer module; I can't tell you what you'd be up for there.

 

I do not get ANY consideration from them, but the folks @ e-trailer*com would likely be a good resource.

 

I'd be a lot more worried about a 14 year old radiator, assuming this project is meant for the 2006 Prius listed in your profile.

Trailer brakes & controller are well within the capability of a healthy Prius 12v battery.

 

Well, I've towed with old cars too. It can be done, but a little planning and awareness now goes a long way when you're in the moment with a loaded trailer.

Radiator performance is a real thing- it may have the extra buffer needed for towing duty when new, but after x years the mineral deposits build up and there just isn't as much heat transfer anymore. I'm led to believe that in a Prius, the early symptom is the air conditioner cutting out- the computer is predicting an overheat and turning off non-essential loads to preserve cooling ability. It doesn't warn you about this anywhere, it just does it.

So if you tow with an older Prius, look out for that. You'll want to make sure your tires & brakes (especially fluid) are on the young side; that goes for any tow rig.

 

Well that's one way to do it! I'd imagine a new radiator is south of $200 though, if that factors against welding school.

 

I've never heard of radiators being the problem attributed to this. The issue you speak of is related to inverter coolant pumps (ICPs) becoming less efficient over time and so pump less and less coolant until they finally fail and circulate no coolant. The car can still function under a light workload, but as the workload increases and the inverter gets hotter it will throw a DTC (diagnostic trouble code) P0A93. When this happens the system does indeed shut down things to lighten the load, starting with shutting off the A/C compressor. Replacing the ICP is a quick and (relatively) easy job to DIY. OEM pump and some coolant. Some aftermarket ICPs have been documented failing early and/or working intermittently. It makes sense not to penny-pinch with this as a new OEM will go 100,000 mi before you will need to do it again.

Instances of clogging seem to be credited to adding stop leak products or mixing different brands of coolant, from cases I've seen.

 

Having towed many times with GEN III (2010 and 2015) I would like to offer opinion. Based on having the 1.5L engine, the age of your vehicle and your planned tongue, empty and load...trailer brakes are over kill. If you really do need them...then you are towing way over anything considered close to safe...in the real world. That said, many hear believe and told me not to tow class 1, but I still did/do, but never exceeding mid class 2. Best wishes what ever you do. As already implied...you vehicle must be serviced fresh on a severe duty cycle and in excellent mechanical condition.

 

Thanks for the amplification/clarification. The only Prius I've towed with is my own, and it is too young to have these problems.

 

With those additional details? Yeah, I wouldn't bother with trailer brakes either. But please make sure your tires and brake fluid are new-ish, and you'll want to check all of the cooling systems, including the battery cooler fan.

 

Additionally understand...your mpg WILL take a hit.

 

Because the Inverter runs the AC compressor! It will also reduce DC-DC power to relieve the thermal load on the HSD cooling system.

Overheating the ICE is a completely possible, although abnormal result of towing. Overheating the HSD system, on the other hand, is extremely unlikely barring an underlying condition.

Yea, no reason AT ALL to put any stop-leak or other non Toyota approved fluid in the HSD cooling system.