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crx
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Discussion Starter #1 (Edited)
if your main relay is acting up or has gone bad this is a way to get it fixed with a standard 4 pin automotive relay you can find for around $5.

it is also an upgrade from the stock main relay. as you will see in the pick below the main relay send power directly to the fuel pump and works on a circuit board with paper thin copper foil.

im assuming that fuel pumps dont take too much current to run since i was running a walbro 255 on the stock main relay and wiring.

material needed
1 automotive relay with harness ( i used a basic 30 amp 4 pin)
**** if you cant find one with a harness you can use female quck**** **** disconnects onto the relay directly ****

5 male quick disconnects
**** one of them must be larger to hold 2 wires to bridge required **** **** terminals ****

heat shrink wrap for each quick disonnect


i wasnt able to find a harness for my relay so i only have a pic of the prototype that i slapped together.

the wiring instruction are simple just check the correct diagram below. ive got it figuered out for the larger acura main relay but i need to fidn a pinout for the harness, the integra main relay is the same as the one one as the honda"s.
 

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Poop Sock
wrx & slut rex
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3,798 Posts
every single time I've ever had a main relay problem I've taken it out, held it about waist high from the ground, Drop it on the pavement, and reinstall. lol thats it. its worked every time for me. Ive done this with two different relays and its worked. just an old trick i guess ha. good DIY!
 

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crx
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Discussion Starter #5 (Edited)
its not just a fix but an upgrade. a fuel pump shouldnt be getting power from a flimsy copper foil lined circuit board.

maybe its all in my head but my idle seems smoother.

another thing that is cool is you can use it as a security feature. i know a guy that puls his main relay when he parks his civic at work cause it was stolen. with a regular relay its liek 3 times small and can fit in your pocket a lot easier. plus it would make it easier to wire in a turbo timer or remote start.
 

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1992 Civic Si
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1,671 Posts
Theft doesn't count
Okay, $3

its not just a fix but an upgrade. a fuel pump shouldnt be getting power from a flimsy copper foil lined circuit board.

maybe its all in my head but my idle seems smoother.

another thing that is cool is you can use it as a security feature. i know a guy that puls his main relay when he parks his civic at work cause it was stolen. with a regular relay its liek 3 times small and can fit in your pocket a lot easier. plus it would make it easier to wire in a turbo timer or remote start.
I know DSMs have this issue, with the fuel pump getting power from a shitty circuit. I don't think Hondas have ever had an issue with it though.

But I like the idea of taking the main relay with you as anti-theft.
 

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Classic Man
Civic
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16,355 Posts
I know DSMs have this issue, with the fuel pump getting power from a shitty circuit. I don't think Hondas have ever had an issue with it though.

But I like the idea of taking the main relay with you as anti-theft.
a very common upgrade for high HP hondas is to wire power directly off the alternator, to the fuel pump, using a relay connected to the stock power source for a switch.


not saying replacing the stock relay will do the same thing... but its gotta be better... at least, until the chinese $5 relay bites it. heh
 

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crx
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Discussion Starter #10
around my way all the main relays are gone. finding a main relay in a salvage yard around here is like finding a honda distributer or manual tranny ECU!! all the honda guys out here know what to grab when a car comes in fresh. i know guys that go to the yard everymorning to check on fresh hondas and integras. on top of that you got honda enthusiast workign at teh salvage yards and selling stuff locally on ebay. my boy miguels garage is ful of stuff. once oen of those gusy tried selling me a vtec spool valve for $100 it took me a while befor ei found one on here. it held up my head swap for months.

now you dont have to haggle with salvage yard buzzards for a main realy!!!
 

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I always just re-flow the solder on them. Haven't seen any other failures other than cold solder joints.

I just made a dedicated power circuit for my fuel pump.
 

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crx
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Discussion Starter #12
i always hear about the solder fix. but for those who cant get ahold of a sodlering iron or have no idea how to use one this is way easier.
 

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89 HB, 93 Legend
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ya i live across the street from a junkyard and finding parts at a good price are hard to come by they wanted 180 bucks for a crx dash they said they would take 130 if i gave them the one out of my civic. I have had pretty good luck with just reflowing the sodder joints myself.
 

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89 Civic Hatch DX
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I always just re-flow the solder on them. Haven't seen any other failures other than cold solder joints.

I just made a dedicated power circuit for my fuel pump.
Did the same to mine last year was free to do and have not had a problem since.
 

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around my way all the main relays are gone. finding a main relay in a salvage yard around here is like finding a honda distributer or manual tranny ECU!! all the honda guys out here know what to grab when a car comes in fresh. i know guys that go to the yard everymorning to check on fresh hondas and integras. on top of that you got honda enthusiast workign at teh salvage yards and selling stuff locally on ebay. my boy miguels garage is ful of stuff. once oen of those gusy tried selling me a vtec spool valve for $100 it took me a while befor ei found one on here. it held up my head swap for months.

now you dont have to haggle with salvage yard buzzards for a main realy!!!
Off topic, but I can only extend my sympathies to you. I'd say Hondas around where I am go to the crusher about 60-80% untouched. In fact, I don't know if I've seen a Civic that's EVER had its main relay removed ... well, ok a couple of times. But that is the exception, not the rule. I frequent a couple in my area and there are still 5th Gen Coupes with the front spoilers on them, ECUs intact, clocks and black armrests still in them ... hell I even saw a cluster w/ tach sit around for 8 months before I finally pulled it myself for a project.
 

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crx
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Discussion Starter #19
wow. i woudl actually like to get ahold of a Ek cluster with wiring myself. i want to put one in my rex.
 

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my name says Guest, but Im really a MEMBER
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I personally haven't replaced a main relay on anything. it's always spark. I dunno what the hell you guys are doing to your main relays.

ok, one accord at a shop I worked at need a main relay.
 
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