Thread: Diesel 2A and 3 ignition wiring differences 2.25 litre

As with other Landrovers, the diesel 2a changed polarity from positive to negative earth in 1967. At the same time there were other fairly significant wiring changes. Post this swap the circuit should be similar to the Series 3 except for obvious differences due to where the instrument panel is.

Note that 2as had generators not alternators, and early diesels (not sure when this changed) had two 6v batteries in series, one under the seat. This is likely to have been changed by now in early ones.

I'll see if I can find the circuits and compare the in the morning.

Originally Posted by JDNSW

As with other Landrovers, the diesel 2a changed polarity from positive to negative earth in 1967. At the same time there were other fairly significant wiring changes. Post this swap the circuit should be similar to the Series 3 except for obvious differences due to where the instrument panel is.

Note that 2as had generators not alternators, and early diesels (not sure when this changed) had two 6v batteries in series, one under the seat. This is likely to have been changed by now in early ones.

I'll see if I can find the circuits and compare the in the morning.

Hello John,

Thank you for the detailed reply. I did not realise that the early 2As had two six volt batteries. Have you been able to sort out the supply of a new alternator for your County yet?

Kind regards
Lionel

No. The mechanic who has it is getting a friend who is an auto electrician to sort it, but he is only available weekends. I will phone him Monday to check on progress.

I owned a 1961 2a diesel from 1965 to 1969, so my memory of details is a little hazy.

Having looked at the wiring diagrams, I can add more information. There were two different switch arrangements for positive earth 2a diesels. Early ones had separate switches for heater plug/starter and for electrical services (combined with the light switch. Only the start/heater plug switch is keyed. Both this and the combined heater/sevices/start switch are below the instrument panel next to where the choke is on the petrol on. The choke knob location is occupied by the engine stop knob on both types.

I can confirm that both the 2a and 3 have the same electrical arrangement of the heater plugs - plugs in series, and a resistance in series with them, and a warning light paralleled with the resistance.

Note that 12v replacement heater plugs exist, and require the wiring to be changed to parallel.

Hope this helps!

Hello John,

All the best for forward progress on your County.

I chased some wires on the 2A and found that a yellow wire had come off the starter motor. I also unwrapped the insulation tape that bound 4 wires and started to chase them back. The were two red wires in the bundle. 1 red went to the alternator and a green wire went close by. I took a photograph of the back of the alternator. The photograph showed a brown rectangular plastic box with a the brand Bosch and a product code of EE14V13 9190067015. A quick search identified the brown box as an alternator regulator. I am interpreting this product code as being a regulator that is fitted to a Bosch alternator and not a Bosch generator.

The other red wire connected to the starter motor as too did the previously mentioned yellow wire. All the wiring was single colour generic wiring that I traced back to respective joins in the cloth covered wire loom. Some wires look like they branch off and go through the fire wall into the gauge cluster area.

I have noticed increasing amounts of dark khaki paint laying underneath a top coat of blue paint. I have yet to read the chassis and engine numbers. However, I am starting to suspect that the short wheel base 2A might have been an Army vehicle - so petrol engined. Then a later owner may have done a 2.25 litre diesel swap. A check of chassis and engine number will provide some more light onto the past history.

After some hours working on chasing different wires in the 2A I am leaning on taking a short cut by temporarily removing the switching components from Series 3 diesel and transferring these components to the 2A. The Series 3 wiring system works. The motor was tired when I bought the vehicle. However it did start with a turn of a key. Therefore, I know the system works. Who knows - the motor in the 2A could have been from a Series 3 donor.

Thank you for your insight John. Have a good weekend.

Kind regards
Lionel

No 2a Landrovers had alternators, but many, including mine have been converted (my current 2a has an S3 alternator - and metric speedo - and doors - and seats and County wheels, and probably a few other bits as well! Typical things for Series Landrovers today.