Ignitian failure.

[John1971]

Hi All,
This is my first post of many to follow. At present I am restoring a 1971 B. We are the 2nd owner, this is a pretty cool story. My older brother now at 61 and his best friend bought there MGBs new in 71. My brother kept his until he started a family and then it was gone. His friend went to Florida to college, got back home in 80, built a house and his B sat in his garage since 83. I bought it last November from him so he could see his west side of his garage. My wife had a 1972 B when we met 20 years ago, we also sold hers back then, no car seat room. I had a 71 TR6, so I do have a pretty good grasp of little English cars. This is my Problem, the electrical system is up and running, I've got a strong starter and have turned over the motor many times with the ignitian switch. The other night I removed the center console to check a conection which was fine. I went to turn the starter and the starter was dead. All else works, the funny thing is that the previous owner installed a timing jog switch for the starter and if I use that switch the starter rotates. Any Suggestions on this, I can't find a fuse not to say there is not one hidden somewhere. Thanks for any help I can get on this. John1971

[paul J]

Originally Posted by John1971

Hi All,
This is my first post of many to follow. At present I am restoring a 1971 B. We are the 2nd owner, this is a pretty cool story. My older brother now at 61 and his best friend bought there MGBs new in 71. My brother kept his until he started a family and then it was gone. His friend went to Florida to college, got back home in 80, built a house and his B sat in his garage since 83. I bought it last November from him so he could see his west side of his garage. My wife had a 1972 B when we met 20 years ago, we also sold hers back then, no car seat room. I had a 71 TR6, so I do have a pretty good grasp of little English cars. This is my Problem, the electrical system is up and running, I've got a strong starter and have turned over the motor many times with the ignitian switch. The other night I removed the center console to check a conection which was fine. I went to turn the starter and the starter was dead. All else works, the funny thing is that the previous owner installed a timing jog switch for the starter and if I use that switch the starter rotates. Any Suggestions on this, I can't find a fuse not to say there is not one hidden somewhere. Thanks for any help I can get on this. John1971

If it workd before you checked some connections, you probably have a bullit connector that's not making contact properly. Very common on MGBs. It's painfull task, but you should pull all the connectors, clean them, apply a very small amount of dielectric grease to them and put them back together. DO NOT use regular grease! If you can see the grease, you put on to much. You do this one at a time as not to cross any wires. Have fun! Most of us have been there.

[Flash75]

Go to this site and download wiring diagram for your model year car. On the left click on stock schematics, then MGB.
http://www.advanceautowire.com/
Where is the jog switch connected? knowing that may help eliminate some checks. Your car should have a start relay. It's just behind the fuse box. The first check I would make is to have an assistant turn the ignition to start while you have your finger on the relay, if working you can feel and hear the relay clicking. If it clicks the relay coil should be good but the contacts inside the relay may be bad. If no click, turn the ignition to start and check for 12 volts on the white/red wire on the relay. If it doesn't have 12 volts trace the wiring back toward the ignition switch and repair as needed. If you have 12 volts get a jumper wire with two clips on it. Make sure the transmission is in neutral, hand brake on and your feet not in front or behind the wheel. Jumper the brown relay wire to to the white/brown relay wire, does the starter crank? If yes I would check or replace the the relay. The OE type relay is rather expensive, you can use standard relays from NAPA, Advance or others. The terminals will be labled differently. The white/red wire connects to relay terminal 85, black to 86, brown to 30 and white/brown to 87.

Clifton