Quote:
Originally Posted by jmcelroy
You make a good point. I had not considered the energizing voltage (pull-in) threshold to make the relay function. I looked it up and it seems pull-in is usually around 8-9VDC for these 12V relays so not a great candidate. I was going to test last night . . . but real life got in the way.
Can't find any documentation to support but can we assume that brake controller output on blue wire is between 3VDC and 12VDC depending on mode and pedal force applied?
Anyone got facts here?
I looked up a 6V relay and it may have the right specs to work for this use case.
Nominal Voltage: 6 VDC
Operate Voltage: 3.9 VDC MAX
Release Voltage: 0.6 VDC Min
Operate Time: 8 mSEC Max
Release Time: 8 mSEC Max
Temp Range: Operating -40 C to +85 C
Contact Arrangement: 1 Form C (SPDT)
Contact Material: AgSnO Silver Tin Oxide
Contact Millvolt Drop: 200mv @ 35A
Max Make Current: 90A/30A @ 16 VDC
Max Break Current: 40A/30A @ 16 VDC Resistive
Max Continuous Current: 40A/30A @ 23 C, 35A/25A @ 85C
Initial Breakdown Current: 500V RMS Contact to Coil
Expected Life: 100.000 Operation 40A 14 VDC Resistive on Normally Open Contact
SPDT(31.6x26.5x50.8)mm Plug-In I hear you on this being a tow vehicle wiring problem and not a controller issue. I don't know enough about it to weigh in but it seems reasonable. Given that the pinouts for all of the tow controllers I've looked up only have brake pedal signal as input and trailer connector (blue wire) as output, it seems even more reasonable.
Guess I'm gonna not gonna have override lights on my camper.
Thanks for your research on this.
Jason |
Yeah it’s big bummer that Toyota computer logic can’t see passed it.
To answer your question on brake controller operation, they have inertia sensors so really the pedal application input is just on or off. The force with which the pedal is applied is calculated via the inertia sensor in the brake controller. The settings I would guess range from 0 volts to charging voltage (13-14volts?) In my trailer set up I run Redarc at about 4 on the dial so what’s that like 40% give or take of max? So on light brake application (less extreme inertia/momentum shift present) the brake controller is going to apply UP TO that 40% mark. So even less than the 5 or so volts.
But all we’re concerned with is manual override which does the full value of which you have it set. So the 40% in my case during manual override. During normal braking the brake lights operate just fine remember. We’re ONLY concerned with manual override having the issues.
Therefore it’s unlikely to ever be much less than the 5 or so volts for most folks with these 4runners. But it could be higher I would guess.
Meaning even further, your 6 volt relay idea would probably work just fine.
The idea I came up with used a seperate feed line off of the back-feed principle through the trigger line stated earlier since we know the brake input is a 12v feed we could use for a relay
I say “magic box” because on a trailer the turn/brake is the same light but on the 4runner they’re seperate. Somewhere they combine. On my 95 4Runner there’s a magic box you buy to install between tail lights and trailer plug that combines it all.
Basically you mimmick the feed source to the plug instead of the output source. Still need 3 diodes and a relay and run of wire to and from the 7 way plug and brake controller. Pain in the ass regardless.
Linear Mode
