MG Car Repair: 1976 MGB wiring issues, replacement solenoids, spade terminals

Question
QUESTION: I am helping my buddy work on his 1976 MGB. We recently replaced the padding on the dash, and so we had the guages unhooked. Also, the starter had been removed by somebody else and so we replaced that as well. I don't think our problem is coming from the dash, as we only replaced guages. When replacing the starter, the thread from the solenoid that the batter positive cable hooks to partially stripped. We were able to place the batter cable and one other set of the brown wires onto the solenoid this way still. We used the large quick connect port to replace the other 3 or 4 brown wires. By buddy also hooked a white/light green wire to this. After hooking the battery back up we noticed the fuel pump ran regardless of whether the ignition was on or not, which it did not before. Also, we started the car and timed it fine, but the ignition switch would not turn the car back off. We got it turned off, but somehow we have bypassed the ignition switch. I have looked in the book at the wiring diagram, but I am not very experienced in wiring. After unhooking the white/light green wire i get no power except for the headlights? Any suggestions?
Thanks,
Paul

ANSWER: Hi Paul,
Down at the solenoid there are several plain brown wires. All of these PLAIN brown wires must connect to the battery cable post on the solenoid. In addition there should be two other wires down there. One is white with a brown tracer and the other is white with a light green tracer. There are two flat spade connectors on the solenoid that are by them selves and not attached to the battery cable terminal. They are usually two different sized flat spade terminals so that the two white wires can not get mixed. However, I have seen replacement solenoids that had both the same size.

Connect the battery cable wires up first, then take a short jumper wire and connect it to the battery terminal and with the other end, touch each of the two independent flat spade terminals on the solenoid. (BE SURE THE CAR IS IN NEUTRAL) One of the spades will make the starter engage. The other will not. The one that makes the starter engage is the terminal to put the white w/brown tracer on. The other (usually smaller) will be for the white w/light green.

If you connect it up like that and there is still some problems. Then the problems are elsewhere.

Let me know,
Howard

---------- FOLLOW-UP ----------

QUESTION: Thats excellent info Howard, thank you very much. Let me give you an update though, as we mistakenly happened upon some further info that leads me to believe that the problem my in fact be elsewhere. While trying to temporarily install a radio into the car the following happened. We were attempting to direct wire the stereo to the battery. We connected the ground from the radio direct to the ground on the battery, and were going to do the same with the hot wires. When we did this the car hot wire was on the batter, but the car ground wire was disconnected. As soon as we grounded the radio, the fuel pump turned on. We think this may mean that the positive is grounded directly to the car somewhere along the way. Could that be accurate? Its a little perplexing because everything seemed to work so well before.

For clarification on the small wires. Originally the white/light green wire was not hooked up at all. The white/brown was and is again to a small lead on the solenoid. Also we used the large lead to hook some of the brown wires because the nut partially stripped. Could that be part of our problem?

Thanks for all your help,
Paul

Answer
Yes Paul, I think all of that has combined to make up your electrical problems.

You need a wiring diagram and start at the battery and correct everything from there out.

Remove all the fuses and correct the battery leads then install one fuse at a time and read the diagram to test each and every item operated by that fuse and correct any item that don't work. Then proceed to the next fuse, etc, etc, until you have every fuse in and all items tested.

That is what we had to do in some shops I worked in when we had one with many electrical problems.

Howard