Additional Fuse and Relay combo box

[stallie]

(I thought this specific enough to keep separate from my other thread about the loom replacement)

As part of the loom modification and replacement and the existing upgraded alternator, I'd like to neaten up all the relays and extra circuits that I am putting in, and thought, again, that I'd get some feedback on an idea that I think has some promise.

I've come across this product - https://www.swe-check.com.au/catalog/9040.pdf there are a couple of variants, but there is one that has a bus for power in that feeds into 10 micro blade fuses. 5 of these fuses feed into to pin 30 on 5 micro relays, and the remaining 5 fuses remain as just fuses. The 5 relays share a common earth, further reducing wiring. The box is small about 5" x 3" x 3" and would fit neatly on the LH wheel arch (RHD) and hopefully tidy up all the messy wiring with relays there.

So in a nutshell, after upgrading the power feed via the N wire to 60A from the Alternator to the common bus point on this unit (effectively where the infamous block is).  The existing 3 Lucas fuses (red purple and green circuits) stay intact but everything else comes from this box.

The wiring I'm thinking of (I've decided against the Revotec fan (have the oil cooler) and now decided to protect the headlight circuits).

Fuse Bay 1 -> Fuse 15A -> relay for fuel pump -> switch input from W wire from Inertial Cutoff-> output35A WP to fuel pump (higher diameter due to voltage drop)

Fuse Bay 3 -> Fuse 10A -> relay for Stereo -> switch input 8A WK from ACC on ignition -> output WK 17A to stereo

Fuse Bay 5 -> Fuse 10A -> relay for Air Horn ->switch input 8A PK (keeping the original horns PB) -> output PY 17A to airhorns

Fuse Bay 7 -> Auto reset CB 10A -> relay for Low Beam -> switch input UR wire -> output UR 17A to low beams

Fuse Bay 9 ->  Auto reset CB 10A -> relay for Low Beam -> switch input UR UW wire -> output UR 17A to low beams

Fuse Bay 2 -> Fuse 10A - USB ports in cabin PG 17A

Fuse Bay 1 -> Fuse 15A - Cig plug USB port PU 17A

Fuse Bay 1 -> Fuse 5A? - Dashcam

Fuse Bay 1 -> Fuse - spare

Fuse Bay 1 -> Fuse -spare

Obviously anything fused through here is always live.

I'd appreciate any problems anyone sees with this plan? I think it would be neat and reduce a lot of spare wiring and thus hopefully be neater and more importantly more reliable. I've learned a lot on this loom project, but also don't know what I don't know....

Thanks

Dan

Edited May 14, 2023 by stallie
corrected UW typo

[RobH]

Sounds a plan Stallie.  I can't see any drawbacks.  I guess it is a typo for bay 9 and that should be high beam with UW wires?

 

[KiwiTR6]

Just a word of caution, those micro relays can be problematic.  We have them in some of the products we sell and they fail on a regular basis.

[RobH]

39 minutes ago, KiwiTR6 said:

they fail on a regular basis.

Interesting.  

These are an ISO standard part produced by a number of manufacturers. There is really no reason why they shouldn't be as reliable as any other relay if operated within the specified parameters.  This for instance quotes expected mechanical life of 1 million operations. Maybe the failure is something to do with the circuit they are used in?

https://docs.rs-online.com/a216/0900766b80e1ff89.pdf

 

 

Edited May 13, 2023 by RobH

[stallie]

8 hours ago, RobH said:

Sounds a plan Stallie.  I can't see any drawbacks.  I guess it is a typo for bay 9 and that should be high beam with UW wires?

 

Thanks again Rob, will report back when I get some time to set it all up.

(corrected typo).

[KiwiTR6]

On 5/14/2023 at 9:33 AM, RobH said:

There is really no reason why they shouldn't be as reliable as any other relay if operated within the specified parameters.

Our products predominantly use Bosch sensors.  Again, not as reliable as you'd expect, but it comes down to the country of manufacture. The same applies to the relays regardless of the specification.

Edited May 15, 2023 by KiwiTR6
spelling

[stallie]

Thanks. I’ll make sure I keep a spare relay in the kit. 

[KiwiTR6]

3 hours ago, stallie said:

Thanks. I’ll make sure I keep a spare relay in the kit. 

 

[CK's TR6]

I have a 5 circuit box on my car (LHD). It is mounted on a bracket (go binky), that picks up one of the lower bolts for the front wing in front of the wheel arch and the two bolts for the bumper bracket (76). It is a sealed unit.  It has the following loads, high beams, low beams, fog lamps, electric fan, and an extra set of horns. It fed directly from the alternator (90 amp) and each relay triggered by the respective circuit. 10 years or more of use. Only issue ever is it popped the fan fuse when the fan motor seized. Not the most convenient location but it is out of the way, and is closely located to the various loads. the fog lamps come on with the running lights, there is a sealed toggle switch to disable this feature. i did have to make a “bullet connector”. I took a six way and cut the center out, then soldered a two way to a four way and then slipped that into the cut six way rubber cover.