View Full Version : How To: Crimping Relay Terminals

08-13-2013, 08:31 AM
With all the bad relay grounds users have been finding. I decided to start a how to for crimping the open barrel type terminals. Its pretty simple and after you try a few you can get perfect crimps.

My crimper is a Tool Aid type with different dies for different type of terminal crimps. I use this for both open barrel and non-insulated closed barrel terminals. This crimper crimps both the wire and insulation with one operation. You can get some crimpers that will do those two crimps with two separate operations. I bought this crimper on EBay for about $70.

The terminals with correct latch pin for our relay sockets are:

AMP 42100-1 for 14 18 AWG wire. Digi-key part number A27935CT-ND

AMP 60253-2 for 12 16 AWG wire. Digi-key part number A27937CT-ND. Use these for 12 or 10 AWG.

Put the pin into your crimper and close it just a little to hold it in place.
Strip your wire to the length of the smaller part of the terminal. The second part should crimp over insulation to give the wire more stress relief.
Stick the striped end into the terminal now held in the crimper. You will feel where the insulation will butt up to the correct position.
Close the crimper fully while holding the wire in place.

Note when you install the jaws (dies) in the crimper that the larger gauge crimps are closest to the handle. That makes less work for those large gauge wires.

I also use STRIPMASTER by IDEL wire stripers. Working in tight areas these hole the wire and make great wire strips without nicking wire.

08-15-2013, 05:05 PM
Good idea making this thread. If I may follow up with some advice I have learned over the years (Read: Mistakes I've made).

1) Do NOT cheap out on the crimper! Yes its an expensive part (I got mine on Amazon for about $70 as well, it even came with like 6 sets of jaws/dies), but spending money on it now mean no headache later. If its not in the budget, inquire about an AutoZone tool rental.
2) Do NOT cheap out on the terminals! They are a little pricier than the metal barrel ones you find at AutoZone or other stores, and ordering online does not help you in a pinch, but they are much better in the long run.
3) Always, always, always tug your crimps after making them. Grab the wire in one hand, the terminal in the other, and just give them a slight tug (once for each wire if you are crimping two wires in to one terminal). No need to use excessive force, just enough to make sure the crimps are well in place or have not damaged the copper strands themselves. Any slippage/copper ripping means you are probably using the wrong die/wire/terminal size and you should go over everything again to make sure its all correct and secure.

08-16-2013, 08:48 AM

could you add a picture of the die you use for these, please?

I have a good (Ideal, I think) crimper, but it only has a die for butt/closed connectors.

08-16-2013, 10:02 AM

could you add a picture of the die you use for these, please?

I have a good (Ideal, I think) crimper, but it only has a die for butt/closed connectors.

This die folds the edges into the stands of wires. Make a pretty reliable crimp which I normaly don't even solder.

08-16-2013, 12:10 PM
Good lessons!