Heated Seat/Electrical/Relay Question

[spedrcr]

Specs are the following;

1987 targa, 150K miles, fabric seats, CrimeStopper heated seat kit from Amazon.

My question may be premature as I have yet to reinstall the seats into the car so I'm not sure if the heat works. That said, the kit has high and low settings. Lights work for both high and low settings. Red for high, green for low. But the relay pictured below only clicks when I switch to the low setting. No clicks when I go to the high setting, whether I am going form low to high or off to high. Based on the diagram on the relay, I would assume I would get a click when I go to high.

Should it click when I go to high? I have a test light and some beer. That is the extent of my electrical knowledge. Maybe I take the relay to NAPA and ask for a similar one as a tester? None of the spares in my toolbox have the same diagram.

Thanks in advance.

By the way, heated seat install is in prep for RR6 road trip from Seattle and back of course. Nice modern accessory in a targa for sure.

[Canada Kev]

What diagram are you referring to, the little one on the relay?

Are you running all the current for the heaters through the switch or are you using the switch to trigger the relay?

I think I'd use the off/high/low switch to trigger the relay to run the higher current for the heaters through that relay. In that case I think you would need an individual relay for each of the heat power circuits, one for the higher power and another for the low and have the switch turn the system OFF or operate the trigger voltage for each of the HIGH and LOW relays. This may be a less elegant way of wiring it than some would come up with, but it's pretty simple.

[spedrcr]

I started with using this harness from Dennis "The Wiring Genius" here on PP Forums



I then connected the heated seat kit wiring to Dennis' harness. All wiring from the kit goes to/comes from the relay as pictured in the first post. So to answer your question, the switch wiring comes from the relay and goes back to the relay. The heated pad also goes into the relay.

Based on the diagram (yes the one I am referring to is the one on the relay) it would appear to me that 87 is the post on the relay that switches between low and high. If that makes any sense...

Maybe I'll just test the seat before final install. Easy enough as I have the bottom cushion and backrest separated.

I believe the switch is triggering the relay.

The post I used as a guide.
https://forums.pelicanparts.com/porsche-911-technical-forum/971766-possible-power-supply-aftermarket-heated-seats.html

[Canada Kev]

On the relay you show, two circuits (terminals 87 and 87a ) have a common terminal (30). When the relay is at rest 87a is connected to 30, and when the relay is energised 87 becomes connected to 30 (but never both at the same time).

The way that relay looks to me, 85 and 86 are the switching terminals, while 30, 87 and 87a are the high current terminals with 30 as the common and the switched terminals being 87 and 87a with 87a being the active one when no switching power is present.

What controls the difference between low and high temperatures on the heating pad? Yes, the switch, but what does the switch control? Is there a rheostat/voltage module that adjusts the amount of power to the heater? Is that part of the switch? From the information you have shown, I don't quite understand the wiring necessary.

[spedrcr]

Any kind of control for the amount of voltage going to the heating pads must be contained within the off/hi/low switch. There are no other parts or pieces in the kit and there is nothing in-line on the wiring between the switch and relay OR the relay and the heating pads.

I'll check at NAPA today re another relay. Along with that, I'll simply plug the seat in and see if I get low and high temps.

[spedrcr]

Thanks for your help CanadaKev. I appreciate your insight.