Coupling relay cables

[Lambo]

I ordered the complete carb conversion kit some time ago... I finally got the engine cleaned up and the stock harness removed. I figured the relay box with the relay cable was the simplest solution to start with... I ran into one problem though, the 4' cable is not long enough. The only place to position my relay box is above the wheel well on the driver's side of the engine bay. I'll need probably another 2 feet... since I already have this one, I'm considering spending the coin a second cable and finding a straight through coupler (these cables look to use the same pattern used on old parallel port printers).

Any thoughts on this... or, better ideas? Would coupling two cables cause any signal degradation problems? Should I just make a new one? Another option I have is actually mounting the relay box inside the cab, and then the running all the sensor, injector, etc. wiring through the firewall. I'd also have to run power and ground back through the firewall... eh, I dunno. It seems like wiring would be much cleaner were the relay box in the engine bay. Coupling a second pre-made relay cable sounds simple too if it doesn't cause any issues.

[Lambo]

This right here would prob get the job done for coupling if I went that route. Says its fully shielded:
http://www.cablestogo.com/product.asp?c ... &sku=02779

[Lambo]

Well... I didn't hear "NO!" from anybody, so I guess I'll give it a shot . No answer is better than a bad answer. My other thought was just build a new cable, but this sounds easier .

[kjones6039]

FWIW...........

I would not mount the relay box in the engine bay. (been there, done that)

The problem I ran into was with water. I got the the board wet while cleaning the engine compartment and MS did not like that at all! I wound up pulling the box, removed the board and dried it before I could get it running again.

In my case, I eliminated the relay board and direct wired the entire setup. (using my own relay setup of course) I found it to be much better for my application.

Just one guy's experience though.

Ken

[jcarruthers]

I agree with Ken.

I don't like the relay box.

You can do everything so easily with properly crimped connectors.

I used these along with multiway connectors: http://www.polevolt.co.uk/acatalog/info_RELF_1KIT.html http://www.polevolt.co.uk/acatalog/Mate ... ctors.html :makes for a very nice fused setup.

Far cheaper and overall I feel a much better job.

[Bernard Fife]

Lambo,

I have used a relay box under the hood of my Corvette for years without issues - certainly never a 'no start'. I do wash the engine fairly often, but rarely drive in the rain (because of the tires and power rather than because of any electrical concerns). That being said, when I redo the wiring for sequential injection and CNP shortly, I will bring the relays into the passenger compartment.

However, before you decide to extend the cable, be sure to do a search of the manual for "gender" to check the manual's advice on gender changers - they probably aren't as straightforward as you hope. They are usually not 'straight-through'. I am not sure how two of them might work, though...

Lance.

[kjones6039]

I used these along with multiway connectors: http://www.polevolt.co.uk/acatalog/info_RELF_1KIT.html http://www.polevolt.co.uk/acatalog/Mate ... ctors.html :makes for a very nice fused setup.

Below is the unit I used to replace the relay board. It provides 4 ganged relays very similar to yours. Although you can't see them in the pic, each relay provides a fuse holder also. These relays require a ground for activation which makes them very compatible with MS!

http://www.summitracing.com/parts/ARC-1440/?rtype=10

Ken

[Lambo]

Well I'm glad you gents chimed in before I bought another $75 relay cable. It sounds like inside the cab is the preferred choice anyway. I like that last relay station from summit too... I'll need something like that to power some other devices (electric fans, water injection, TCC...)

Thanks guys

[jcarruthers]

I used these along with multiway connectors: http://www.polevolt.co.uk/acatalog/info_RELF_1KIT.html http://www.polevolt.co.uk/acatalog/Mate ... ctors.html :makes for a very nice fused setup.

Below is the unit I used to replace the relay board. It provides 4 ganged relays very similar to yours. Although you can't see them in the pic, each relay provides a fuse holder also. These relays require a ground for activation which makes them very compatible with MS!

http://www.summitracing.com/parts/ARC-1440/?rtype=10

Ken

That place also does some nice modular units:

http://www.polevolt.co.uk/acatalog/Modu ... ystem.html

James

[kjones6039]

Very impressive unit for sure. I certainly like the modular concept.

My next project may find me enhancing the UK's GNP!

Ken

[trakkies]

If space is tight it might be easier to use simple relay bases which clip together and mount on any convenient surface. They come with or without a fuse holder. Like these:-

http://www.vehicle-wiring-products.eu/V ... ts.php#box

And keep the number of connections to a minimum for reliability. Car fuses are only to protect the wiring from severe overload - not to protect the device they feed. If that needs protecting it should have its own local fuse, of a more suitable type.

[jcarruthers]

Dave — I bought one of those units — both the fuse and relay. It's actually HUGE when you come to handle it and try and work out where to put it.

In the end I went for the snap together — it has made a really nice compact unit. I wish I had used nicer more compact multiway connectors, the mate-n-lock ones.

it's also pretty nice that you can add almost infinitely.

[trakkies]

Mate n Lock are ok - but I'd go for a waterproof connector if you have the choice.

[jcarruthers]

They're inside the cabin anyway — the only one I have concern is the one I used on my injector loom — but that hasn't had any issues.

[trakkies]

They're inside the cabin anyway — the only one I have concern is the one I used on my injector loom — but that hasn't had any issues.

Even the inside of a car car be pretty hostile to connectors - in some climates it can get pretty damp. A silicone grease can help there, of course. But I'd expect any connector to survive OK for a while. ;-)