Relay Refurb Recommendations

Hello Folks,
So I’m in the process of prepping a new LH Mud shield (thanks Chuck at Monocoque). Wondering if I should disassemble and clean out this horn relay (Series 1) that is mounted on the old shield or opt for a new relay - Thoughts / Recommendations?

Thanks in advance,

When I had a lot of zinc plating done, I had some of the cases replated whilst they were off of the car. The insides are pretty bullet proof - all they need is dressing with some emery paper.

kind regards

Yes I would
Different levels of endeavour…take the relay off the mud shield and sand it with sand paper OR if you have a sand blaster…blast it…the whole thing
Then blow it off…with compressed air or a vacuum
Then with needle nose pliers pry it open…inside are contacts…gently seperate the contacts and slide a piece of sand paper between (anything from 80 to 300 grit) and sand both contacts…careful not to break the thin wires and not bend the contact lever…
While the cap is off…sand some more then spray primer with rattle can…i would not spray the inside (I would maybe sand off any corrosion…then paint with rattle can…any color you want…
Or a step up would be powder coating the cap
Or a step up…Zinc coat it
Or a step up Chrome it…maybe have the only chromed cap
Worst scenario…have to buy a new one
Mitch. it is a journey

Also, on the underside:

Remove all the verdigris on the terminals
Ensure that you have good continuity through the rivets (looks pretty ratty) - might be your biggest problem
Tin the terminals with a coat of regular solder to restore the surface - flux per little can will help flow

I use a spark plug file on internal contacts - no grit residue.

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I sent out the date coded shells with all the plating, and bought NORS Lucas relays, and slipped them in the shells. My secret is out.

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Thanks all… My next project. As suggested, I’ll remove and blast in entirety before opening up.

Mitch and Big2Bird did you both Zinc coat the covers?

Any recommended shops?

I was thinking Cad plating since I also want to get my A-arm trunnion bolts plated as well.


Cad plated.
Burbank Plating.
They do Lenos stuff.

I paint…but there is nothing like perfection

So I must say that after blasting the contacts look much better.

Disassembled yesterday and will clean the internal contacts.

Thanks for the lead on Burbank - contacted them and will get CAD plated (along with misc nuts, bolts, washers etc).

Thanks all - it takes a village…


That will turn out nice.
Don’t go overboard on the points.
The filing thing is another topic. (I advise just contact cleaner).
They seem to be pretty robust units.

If I may add my 2¢ on the subject:
First, take lots of photo’s “as taken off”.
Next carefully pry the four crimps holding the relay internals to the can.
Once the relay mechanism is removed, using a permanent , fine tipped marker, mark the relay number (i.e. 33247, etc.) somewhere on the relay… TAKE MORE PICTURES!!!

Next you’ll probably find the cork gasket has shrunk and hardened. Discard! On re-assembly RTV makes a nice, waterproof seal. Once that’s cured then re-crimp.
A Dremel wire wheel makes easy work of cleaning the male spade connections.
I also keep each relay (when doing multiples) in their own separate Zip Loc bag, appropriately labeled.

Happy Trails,

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Very nice presentation…agreed

Thanks Dick - well noted.
On the RTV, do you apply to the surface, let it cure before reassembly?
Just wondering how you control the RTV thickness to ensure a good seal.

Hi Nick,

Once I’m satisfied everything is ready for reassembly I put a small bead of RTV in the housing lip, the housing lip the bottom board sits on. I then lightly press everything together and use a rubber band and small wood block to hold all together while the RTV cures (usually 24 hours). Then I re-crimp the 4 OEM crimps and the relay is now sealed from moisture, ready for another 50+ years of service.
Another note: I don’t use any kind of sand paper to clean the contacts. I use Crocus Cloth then spray the contacts with Contact Cleaner to remove any residue. A bit of overkill but I don’t want to revisit relay restoration… LOL

Note how the cork gasket has shrunken over time. It now will not seal, keeping moisture, etc. out. The reason for a bead of RTV.

This diagram give a working view of how each numbered relay works along with the replacement number (SRBxxx).
Your effort(s) will pay off in the long run.

Happy Trails,


One point I forgot to mention is the Coil Ohm value. In the 4 relay diagram note each has an Ohm value (approximate). My determination is Low Ohm coil relays are for momentary use, such as a horn relay. High Ohm value ones are for constant use, such as an A/C relay. Just something I’ve noted tinkering with numerous LUCAS relays.

Happy Trails,