
DIY Window Relays
- Hobbawobba
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- Casey
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Re: DIY Window Relays
Hi Jesse - great write-up and really neat wiringHobbawobba wrote: ↑Mon Jun 19, 2017 10:28 pm I installed mine under my passengers seat and carpet. There is a slight bulge () from under the carpet. But you can't see it as the seat covers it anyway. Poke the OEM switch connectors down towards the seat and plug your new relay harness in!
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Can you give a bit more detail as to your wire/harness routing to get from the connectors to under the seat? Did you remove the seat to do this? Is everything hidden away under the carpet?
I have just accumulated all the stuff I need to do this conversion and I need to finalise the location of the relays before I make up the harness.
KIMI 1 : 1st Gen, "hybrid" 1983 silver S2 running gear in a 1985 S3 shell, SORN'd, long term resto project
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8
- Casey
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Re: DIY Window Relays
I have just completed and tested this conversion - all good
I decided on a different location for the required 4 off, single pole, changeover relays. Who needs an ashtray available for the rear seats
I started by disconnecting the battery. Then I removed the centre "armrest" section by:
1. Unclipping the switch panel.
2. Disconnecting the two off 4 pole connectors that feed the window switches.
3. Disconnected the 2 pole connector feeding the rear window washer/wiper.
4. Pulled off 2 spade connectors on the rear electric aerial switch.
5. Removed 2 screws under the switch panel area, another two at the rear of the cubby hole.
The ashtray is removed by taking out two screws.
There is just enough room in the area vacated by the ashtray to position the 4 relays.
The wiring to the relays has to be done very carefully, as the space available is very limited.
Here is one pair assembled.
Wires were crimped, and then soldered, many in this "back to back" configuration, before adding heat shrink sleeving.
Here is the driver's side wired up to it's pair of relays.
And here is the final product, tested on the bench and ready to install.
Close-up of the relays.
I've put a temporary plate over the ashtray aperture, using a piece of ali offcut. I'll tidy it up later.
There was no drilling or cutting/changing car of loom wiring, so everything can be reverted back to stock, ( including the ashtray
) very easily.

I decided on a different location for the required 4 off, single pole, changeover relays. Who needs an ashtray available for the rear seats

I started by disconnecting the battery. Then I removed the centre "armrest" section by:
1. Unclipping the switch panel.
2. Disconnecting the two off 4 pole connectors that feed the window switches.
3. Disconnected the 2 pole connector feeding the rear window washer/wiper.
4. Pulled off 2 spade connectors on the rear electric aerial switch.
5. Removed 2 screws under the switch panel area, another two at the rear of the cubby hole.
The ashtray is removed by taking out two screws.
There is just enough room in the area vacated by the ashtray to position the 4 relays.
The wiring to the relays has to be done very carefully, as the space available is very limited.
Here is one pair assembled.
Wires were crimped, and then soldered, many in this "back to back" configuration, before adding heat shrink sleeving.
Here is the driver's side wired up to it's pair of relays.
And here is the final product, tested on the bench and ready to install.
Close-up of the relays.
I've put a temporary plate over the ashtray aperture, using a piece of ali offcut. I'll tidy it up later.
There was no drilling or cutting/changing car of loom wiring, so everything can be reverted back to stock, ( including the ashtray

KIMI 1 : 1st Gen, "hybrid" 1983 silver S2 running gear in a 1985 S3 shell, SORN'd, long term resto project
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8
- Hobbawobba
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- Posts: 1938
- Joined: Tue Nov 01, 2011 9:44 pm
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Re: DIY Window Relays
Sorry for the late reply aye. I've been slack as!
Hahaha
That came out damn well bro! Good shout on that location
Mine are currently underneath the seats. I may end up re-wiring mine as the switch wires should be able to be far smaller that I originally used
. Power and earth could probably be a touch thinner also 

That came out damn well bro! Good shout on that location
Mine are currently underneath the seats. I may end up re-wiring mine as the switch wires should be able to be far smaller that I originally used


- Casey
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- Posts: 1322
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Re: DIY Window Relays
I used cable rated at 17A (at 12 volts) for anything taking the load of the motors - the copper strands and diameter looked pretty close to the existing OEM wiring cores. The other cabling was just regular "hook up" wiring for the relay operation.
KIMI 1 : 1st Gen, "hybrid" 1983 silver S2 running gear in a 1985 S3 shell, SORN'd, long term resto project
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8
KIMI 2 : 1st Gen, 1983 silver S2 - now sold to Ian Mothersole on here.
KIMI 3 : 1st Gen, 1983 red S3
Plus a 2004 Full Bridgeported RX-8