Electrical Problem

[Lin]

I need a little help getting started with solving this problem:

I am installing a new alternator in my son's Bugeye. We had a Lucas alternator in it before. I have just installed a mitsubishi unit. Had to do a little bracket work and the usual fitting, but in the end I was pleased with the effort.

I had a three prong plug on the Lucas alt. Big spade brown wire from the battery, two little ones - one for the brown/yellow wire that I think is the indicator warning light to the speedo, through the ignition I believe. I forget what the other small wire is, sourced from the no longer used voltage regulator.

On the mitsubishi alternator, the big brown wire (big spade connector) from the battery connects to a scew terminal on the back of the unit. The other two small wires from the Lucas plug were spliced into the Mitsubishi two prong plastic plug and plugged into the back of the alternator.

I then checked my battery -fully charged, and turned on the ignition. Got nothing, No fuel pump ticking, no fuel gauge jumping into action. I have spark to the alternator through the brown wire from the battery. The starter works fine. But, nothing at the ignition switch. No obvious lose wires and everything worked before the alternator change over. No blown fuses.

Can anyone help me with a troubleshooting plan of attack? Probably something silly or stupid that I overlooked.

Thanks.

Lin
1959 Bugeye
1960 BT7 in restoration

 

[dklawson]

Pictures may help if you can post them.

I thought the Lucas alternators with internal regulators had two heavy gauge wires and a single smaller wire to the warning lamp. Others will have to confirm or dispute this. I'm not sure where two small wires from a Lucas unit should/would go.

Usually with Lucas wiring there is a heavy gauge white wire coming from the ignition switch powering both the ignition warning light and the ignition coil. If you have an electric fuel pump installed, that same connection usually powers it as well.

The starter solenoid has power that doesn't pass through the fuse box. Usually there is a heavy gauge wire from the solenoid to supply the fuse box.

My first advice would be to disconnect the alternator and sit down with your manual's wiring diagram (and a volt meter) to see where you've lost voltage. Then, without the alternator hooked up, see how many switched/fused circuits are working and how many are dead. This should help you isolate where you've lost continuity.

Once you've sorted that out you should double-check the connections for the Mitsubishi alternator to make sure 1) that it's not the source of your problem and 2) that you haven't let the white smoke out of it.

 

[SilentUnicorn]

this may help. please note that this is a <u>BOSCH</u> alt. But the idea is the same https://www.cibolas7.net/17901.html

mark

 

[dklawson]

Incidentally, a friend of mine just did that Bosch conversion on his Mini using the information on the link above. He made this decision after getting less than a year's worth of driving on his rebuilt Lucas unit. Time will tell if the Bosch exceeds the Lucas but I expect it will. My friend swears that the conversion was clean and easy.

 

[Lin]

Thanks to everyone for the help. I think I have it figured out now. I have to go out of town for a few days. I will report back next week with an update!
Lin
1959 Bugeye
1960 BT7 in restoration

 

[SilentUnicorn]

i did the Bosch on my 1500, couldnt have been easier, took less than 2 hours from hood up to hood down. Car idles and runs better, Headlights are Bright and the turns flash like they should. Probobly the best upgrade i can think of.


mark