DIY Window Relays

Anything related to the cars electrics... problems.... mods... fixes etc
Post Reply
User avatar
Posts: 1318
Joined: Tue Nov 01, 2011 9:44 pm
Location: Worcester - UK

DIY Window Relays

Post by Hobbawobba » Mon Jun 19, 2017 10:28 pm

A while ago I made up some window relays as I had read about them taking the stress of our problematic switches which are known to clog up :evil: . It was also said that they would speed up! Thought it made sense and was a great idea! :D . Anyway I'll try and show you guys how I done them in my car. I got the inspiration from these few threads on Ausrotary. My ones are more like Sim_Rx3's (under seat and professional) as he seems to have a pretty good reputation over there aye. :D Sim_Rx3's Has before/after times FC write up for more reading ... 32&start=0Arran had a different style :)

Sim also recommends making sure the windows are aligned and lubed up with some dry graphite grease as it won't get dirt and gunk stuck in it 0-0

All connections I used are done properly with interlocking relay bases so the connections don't fall off, heatshrink and OEM plugs. Not using those horrible red/blue/yellow crimp terminals! :evil: . I didn't solder anything. I got most of my products from If you sign up to their newsletter they often send 10% off codes yay. Quick shipping, good prices and awesome quality s(c) . They also have a points system on their website which = $$. So the more you spend, the more points you earn. I learnt quickly not to cheap out on this stuff by buying from ebay as wiring tends to be terrible quality and straight up dangerous. Anyway here are links to the products I used. Lots of terminals as they come in handy for other wiring :lol:
Lengths of cable will depend where you plan on putting your relays. I believe I put them 40cm away which gave me some extra black and brown to daisy chain. You can only buy cable by the meter. I also got tinned thin wall cable instead of plain copper thin wall. It doesn't really cost much more, so why not?
  • 3 meters - 2.5mm2 - Black
  • 2 meters - 2.5mm2 - Red
  • 2 meters - 2.5mm2 - Green
  • 2 meters - 2.5mm2 - Brown (blue would be more appropriate, but they didn't have any when I ordered) :lol:

I also bought some OEM connectors from the following website. They're awesome. You need to spend a minimum of $20(?) or shipping will be ridiculous. At least when I ordered anyway. If you have some spare connectors, then you won't need these. Scroll down to the Yazaki connectors ... ctors.html

You can use heatshrink or braided sleeving to protect the wiring and make it look more professional. Can't remember where I got it from or the size I used, but it's easy enough to find. Adhesive heatshrink is used on all the relay base crimps. I'll leave that for you to decide on.

Think those are all the products you need.


Here is a diagram I made for the way I wired them up. This is per switch! So you will need to wire up 2 of these. One plug goes into the OEM chassis loom and one plugs into the OEM window switch. Note that I used brown cable whilst the OEM will be black with a blue stripe. This is why I recommended using blue instead of brown.

Here they are wired up and heatshrinked. It's hard to find a picture that shows the daisy chain of crimps. Zip ties were to keep everything together tidily. Remember to use the larger female crimp terminals to fit 2 ends of the cable in (for the daisy chain)

Crimped ends and new OEM plugs. I didn't heatshrink this end as it would be difficult to fit into the plug

Picture of the whole set up (minus 2 connectors)

I installed mine under my passengers seat and carpet. There is a slight bulge ( :shock: ) 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! :D

I timed my passengers window after I installed the relays (needed to adjust the driver side). Each was an average over 3 cycles. There is a noticeable difference :). Pretty stoked with the final result and how they're performing. No worries of switches clogging up either! yay

Down - 4.50
Up - 4.34

Down - 3.62
Up - 3.87

It's probably worth giving the switches a good clean out when doing this mod. Just so everything is fresh and stays that way, thanks to your new window relays! Here is the link how to clean 'em out 0-0

I think that's about it aye. Thanks for reading and I hope this is useful for a few of you! If I have missed anything out you guys have any questions then let me know! :lol: Haha

User avatar
Posts: 240
Joined: Fri Jan 08, 2016 12:25 am

Re: DIY Window Relays

Post by KYPREO » Tue Jun 20, 2017 3:09 am

Great writeup and nice wiring work you did there. th:

This is the best mod ever and probably the first one I'd recommend to anyone with a 1st gen.

User avatar
Posts: 1275
Joined: Sun Jul 06, 2014 10:16 pm
Location: English Riviera - South Devon

Re: DIY Window Relays

Post by DKWW2000 » Tue Jun 20, 2017 7:10 pm

Excellent work & nice clear post Jess s(c)
RX7 FB S3 - RX7 FC TII Vert
Rotaries Previously Owned:-
2 x NSU Ro 80s - 2 x S2 RX7s - Suzuki RE 5 - DKW(Hercules) W2000 - Norton (Krauser) Commander

User avatar
Posts: 5755
Joined: Wed Mar 30, 2011 12:11 am

Re: DIY Window Relays

Post by ian65 » Tue Jun 20, 2017 9:30 pm

that's a great writeup Jesse and top work... they look like factory produced items... you ought to build them and sell them! I'll be following your guide and building some of those. Excellent stuff s(c) s(c) 0-0
1986 Series 3 13B Turbo II
1992 Peugeot 205 1.9 GTI
1975 Honda SL125 Street Scrambler

User avatar
Posts: 1467
Joined: Thu Mar 31, 2011 10:54 am
Location: Staffordshire Moorlands

Re: DIY Window Relays

Post by myatt1972 » Tue Jun 20, 2017 10:43 pm

Thats a mint job Jesse, like Ian says they look factory made s(c)
Thanks for taking the time to do a write up 0-0

Posts: 1866
Joined: Sat Nov 05, 2011 8:07 pm
Location: Feltham, Southwest London

Re: DIY Window Relays

Post by KiwiDave » Wed Jun 21, 2017 9:22 am

If you build them .... buyers will come ;)

Awesome post dude 8-)
1985 Sunrise Red S3 TWR
2003 Mercedes E320 CDI Estate AMG

Posts: 333
Joined: Mon Aug 26, 2013 3:03 pm
Location: Hornchurch, Essex

Re: DIY Window Relays

Post by biznatch » Wed Jun 21, 2017 1:16 pm

Excellent writeup! Those slow windows have always bothered me - especially when they stall :x

User avatar
Posts: 1318
Joined: Tue Nov 01, 2011 9:44 pm
Location: Worcester - UK

Re: DIY Window Relays

Post by Hobbawobba » Wed Jun 21, 2017 8:05 pm

Thanks everyone. It was about time I posted that up! Maybe one day I'll get around to doing battery relocation and alternator upgrades too! :lol: Both of which I was heavily influenced from Ausrotary. Awesome info on there
ian65 wrote:you ought to build them and sell them!
KiwiDave wrote:If you build them .... buyers will come ;)

Awesome post dude 8-)
I had thought about making a bunch of sets and selling them. But got a few things going on aye! Plus now you guys can make your own ;)
biznatch wrote:Excellent writeup! Those slow windows have always bothered me - especially when they stall :x
Don't forget to check your window alignment and seals aye bro! There's a link in my original post which describes how (if you're unsure) :D

User avatar
Posts: 478
Joined: Sat May 07, 2011 5:46 pm
Location: Colchester, UK

Re: DIY Window Relays

Post by Casey » Sat Jun 24, 2017 8:57 pm

Great write-up Jesse - another task to add to the list.......................... ;)
KIMI 1 : RX-7 1st Gen "hybrid"; 1983 S2 running gear in a 1985 S3 shell, SORN'd, long term resto project
KIMI 2 : RX-7 1st Gen; 1983 S2, "identical" twin to KIMI 1, on the road :-)
Plus a 2004 Full Bridgeported RX-8 too!

Post Reply