under-hood add-on relay/fuse boxes

I'm starting to add some aftermarket electronics and want to do a Fitch-style setup with local switches going to remote relays and fuses under the hood, either on the drivers cowl above the washer motor or next to the PDC (if I can clear a spot). At this point I'm just looking at options. Weather proofing matters to me so some kind of box that can be lightly sealed is better than screwing relays to a board. Long term I will probably need two of them, with 6-8 relays/fuses each.

Most of the pics I've seen are the radio shack project boxes... are those low profile enough to fit over the cowl? Does anybody make an actual kit for these things?

I am currently working on this - I'm putting all my relays in a rebuilt stock PDC (I have another one mounted in the trunk area for my OBA relays and such.) Pulled the PDC and bracket from the junkyard for $20, disassembled it fully while sitting by the fireplace at thanksgiving and rewired it to do exactly what I wanted. The bracket is riveted together in the middle so I am going to grind out the rivets and use the top half plus a new bottom half bent to make it fit on the driver side inner fender, where the ABS pump would go.

The only tools you need to disassemble the stock PDC are a utility knife, a long poking/prying pick (a fine punch, a set of cheap stainless dental picks, and a chunk of stainless rod cut from near the top of an old stock antenna do great here), and some patience.

That's a good idea, lots of relays and some heavy duty fuses already in there

I was looking at the Painless weatherproof 20-fuse holder (part 30004) and it's almost $200... yikes

What connectors are you using in the PDC? I have one of these to do the same thing, but the connectors that are used to connect to the relays are pretty odd.

Yeah, I just haven't needed enough relays to have to crimp new terminals yet - I took about a foot of the harness on each of the PDCs I got at the junkyard. When I started working on them I very very carefully used the picks/probes I mentioned to remove all the terminals intact, so when I need another I grab one out of the pile. Eventually I'm going to need to go to the junkyard for another box to scavenge from though.

The disassembly is pretty easy - use your pokey sticks to unclip the yellow plastic sections, then use another sharper smaller pokey stick to release the tiny plastic clips holding the terminals in. The clip is reachable from the top of the PDC with the yellow plastic inserts removed, pull the terminals out from the back. The only ones that are a royal PITA are the maxifuse terminals, I bent/mangled a lot of those (they have a metal retention clip on one side as well as a plastic retention clip on another side.) Luckily I didn't end up needing many.

If you want to rearrange things, each relay block that the yellow inserts go into unclips - there are a couple variants, the one with the ABS relay at the top is one, the ones with 4 mini-ISO relay sockets are another. I've been using the mini-ISO relay sockets because I had more terminals for those and more relays fit into the box that way.

ooohh pretty http://bluesea.com/category/5/21/productline/126

wow, that is really slick looking... if only it had relay slots I wonder if they make one that does.

These actually look the most sensible but I can't find the circuit ratings

http://www.amazon.com/s?ie=UTF8&search-type=ss&index=automotive&field-keywords=DLC

Those "look" like they will handle 20, maybe 25 or 30 amps to me. The maker's site (dlcparts.com) does not list power ratings either as I am sure you noticed.

I tried their contact form we'll see what they say if anything

waytek catalog shows them max of 15 amp, however there are other nice blocks there

http://order.waytekwire.com/IMAGES/M37/catalog/220_074.PDF [PDF]

also, Hella makes some nice 4-relay hold-down blocks, and they can be joined together at the sides to make however many you want

http://www.rallylights.com/detail.aspx?ID=772

I found this a while ago, really nice, but really expensive. Scroll down to the modular fuse and relay housing. The good part is you can really customize it to exactly what you need.

http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/sockets.php#box


The small 4 fuse holders have a max of 50amp total. I actually have a few of the small 4 fuse ones, and one of the 8 fuse blocks sitting at home.

Another good site for them.
http://www.delcity.net/store/Fuse-Blocks/p_176.a_1

ehall said:

ooohh pretty http://bluesea.com/category/5/21/productline/126

Click to expand...

I have one of those in my XJ. Works great!

Begster said:

I found this a while ago, really nice, but really expensive. Scroll down to the modular fuse and relay housing. The good part is you can really customize it to exactly what you need.

http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/sockets.php#box

Click to expand...

that is nice

ehall said:

These actually look the most sensible but I can't find the circuit ratings

http://www.amazon.com/s?ie=UTF8&search-type=ss&index=automotive&field-keywords=DLC

Click to expand...

I would consider those to be maximum 30 amp as that's the largest size fuse in that style.

Begster said:

I found this a while ago, really nice, but really expensive. Scroll down to the modular fuse and relay housing. The good part is you can really customize it to exactly what you need.

http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/sockets.php#box


The small 4 fuse holders have a max of 50amp total. I actually have a few of the small 4 fuse ones, and one of the 8 fuse blocks sitting at home.

Another good site for them.
http://www.delcity.net/store/Fuse-Blocks/p_176.a_1

Click to expand...

That is really awesome, but really expensive like you said. I can buy 3-4 PDCs at the junkyard and patch exactly what I need together for less/same price, though it's not really truly weatherproof.

renix era jeeps had relay blocks you can join together/seperate for as many as you want, had one on the drivers side for the electric fan and 3 on the pass side for various things, i run 2 blocks, 3 relays on each, have mounting holes on each relay, wiring is simple, im redoing it all at somepoint this winter to group all my electrical together and get rid of the renix wiring mess.

I had to go to the junkyard today so I checked for the RENIX relays and yeah the sockets are interlocking. Pretty neat. They aren't waterproofed but it's definitely a step in the right direction. I grabbed a dozen or so and will look at them again later.

Won't another stock underhood relay box be the easiest/cheapest way to go? You could put them side by side so they'd both be near the battery.

Dundy said:

Won't another stock underhood relay box be the easiest/cheapest way to go? You could put them side by side so they'd both be near the battery.

Click to expand...

Exactly what I've done/am working on doing more There isn't space next to the stock one unless you delete or move your coolant reservoir. I'm mounting mine about where the ABS pump would go, on the driver side.