These are the originally specified wire terminal ends for connecting wires into the rear lamps on the MGA. These sleeve connectors are not part of the (original) wiring harness, and may or may not be included with a replacement harness. They are also not listed in the Service Parts List as part of the tail light, so we have to hunt a little to find the part number.

Tubular connectors for tail lamps Sleeve, terminal (3x) 37H5271 or 7H5582

These terminal sleeves are 0.184 diameter and 0.403 long with a flange 0.25 diameter (to stop them falling thru the rather sloppy sockets on the lamp base). Material is plated or tinned brass 0.017 thick. Advantage of this type wire terminal is that you can push the insulated wire through a very small hole (molded, drilled or poked) in the rubber base gasket, then install the wire terminal without need for crimping or soldering. Original method of termination is to strip the insulation back 1/4-inch, push the wire through the tube until the bare wire extends out the end while insulated part of the wire is pushed fully into the tube. Then flare out the wire strands, and bend them back over the outside of the tube before inserting the assembly into the tubular receptacle in the lamp base.

You might solder the wire inside the sleeve, but if the wire is not extended and flared over the outside of the sleeve terminal the connection may be marginally loose in the receptacle tube, possibly not the best electrical connection.

The same tubular wire terminals are used in the rear number plate lamp. The wire terminal part number is sometimes confusing, as for this application the tube terminals are part of a "sundry parts" kit 7H5123 which includes the chrome screw 17H5385 and the wire terminals 37H5271. The part number for the sundry parts kit is sometimes erroneously used as replacement part number for the chrome screw.

Sleeve 7H5123 - Sundry Parts for Number Plate Lamp Sleeve, terminal (2x) 37H5271 or 7H5582 Screw, chrome 17H5385

The front parking lamp (side light) should have three wires (as original). Some replacement parts may have only two wires and may or may not reliably ground on the body of the car. The black ground wire should connect to a tubular receptacle on the side of the lamp socket. When (if) the black wire is supplied with the lamp, the wire might be soldered to the lamp base, or it may have a bullet terminal inserted into a tubular receptacle on the lamp base. If there is no black grounding wire with the replacement lamp, you may add and terminate this wire using the same tubular connector that is used for the rear lamps (if the tubular receptacle is part of the lamp base).