Electrical problem

I have a '73 MGB with '76 engine and am having some kind of electrical issue. Go to start the car and get click-click-click from the solenoid but the battery doesn't seem to be holding a charge and after a while I get nothing when I turn go to turn it over. Get it push started and everythign's ok for a while until the ignition light comes on while I'm driving and the turn signals, radio, horn and fuel and temp guages quit. Used to be that the ignition light would go off after a while at high rpm's and everything would start working again. Now I get nothing, no ignition light when I turn it on and not a sound from the solenoid. I cleaned off the battery cables and terminals but still not behaving. Any suggestions?

Patrick

Take the car to one of the auto parts places that will do a free alternator test (most do nowdays). It will give you a better idea of the real problem.......

Check the battery voltage, Check the alternator could use a rebuild.

I had the same problem on my truck a few weeks ago. Turns out the ground wire to the engine had come loose. A days worth of checking the alternator, battery and starter only to turn a wrench four turns and have it work perfectly.

If you find out that it is the grounding strap being loose, it would be a good idea to have the system checked anyway as an intermittant 'on-off' type of condition could not have done any good to these already aged systems. I hope that you get it sorted out.

Yes I had a similar problem and found the battery ground connection rusty etc. Took it off and cleaned/ sanded the metal, reconnected and worked fine.

I am having a similar problem and I want to clean the ground wire to the engine, but I can't locate it. I know it should be off the transmission, but could anyone give me more a more precise location?

Thanks
Richard

Richard,

I was going to ask the same thing. You saved me the embarassment....oh dang!!!

Patrick

Had similar problems. Ran a thick lead from where the battery grounds at the rear to one of the bolts holding the engine to the gearbox. Ran a second strap from there to the ground point on the fender. No more troubles - it even fixed the intermittant click of the relay but no turning over.

Patrick - you gave me a laugh! I still can't find the stupid thing. I am thinking of running to the auto parts store to buy one and just bolt it on anyway.

Rich

Just located, detached, cleaned and replaced the battery ground strap. While reatthing it I got an occasional "pop" from the stereo but then nothing. Push started agin and no difference. What's with the stereo coming to life and then stopping when I was fiddling with the ground strap?

Richard, on my 74.5 the groud strap is off of the engine mount to the engine bay. It puzzled me and Jim smith for a while cause it wasn't on the tranny.

ok...so far I've located both the battery grounding strap and the engine grounding strap. un bolted them, cleaned them and re-attached them. Still nothing. The interior light works, as do the headlights, just dimly, but I get no ignition light when I turn it on.

You guys are great and I appreciate the tips...got any more?

Patrick

Late '70s Bs have the ground strap attached to the transmission cross member and earlier Bs have it attached to the motor mount.

Sounds like a weak battery and/or alt. problems

Eureka! Got all the ground straps clean but the battery was too weak. Jumped it from my Nissan and everything is working and it's charging! Keeping my fingers crossed.

Once again, you guys are great. Thanks for all the help!

Patrick

I put a new ground strap on from the rear alternator bolt to the front of the engine compartment and I am still getting clicking although it does start on the second or more tries. It starts pretty crisply when it does.

Where is the starter solenoid? Should I check that out?

Thanks!!


Richard

Have you cleaned the contacts on the starter relay??

solenoid is on the starter...Have you checked all of those connections yet?

You should aslo check to make sure the fuse with 3 brown wires is good and tight also check and clean the connections on the starter relay and make sure the starter ground wire is tight.

I am referring to Rick Astleys Book "MGB Electrical systems" it is a good book.

Uh oh! Well, I'm narrowing it down now. Jump started it from the Nissan and left the jumper cables attached. It charged just fine. I took off the jumper cables and left the MG running and soon the battery was drained and it wouldn't start. So I'm thinking either alternator or battery is bad. Here's the thing though...when I first jumped it from the Nissan I got the red ignition light...now I don't get the light at all. Is this a clue as to whether it's alternator or battery?

Patrick

Thanks Paul M for the tips. I think its going better now, probably didn't hurt to clean all those connections. I also ordered to MGB electrical systems book - more bedtime reading. Anyhow I off for a little drive now!

Rich

Patrick, As far as leaving the cables on (did you have both running?) Someone correct me if I'm wrong If you did have both running your alternator is probably toastoes not.

The starter must have worked OK?

If the light does not come on The brushes in the alternator may be worn or the regulator failed.

The starter worked just fine...I'm thinking it has to be alternator. Obviously the battery will hold a charge but with the car running on its own the battery drains fast, so it's not getting a charge...ergo, new alternator!

Patrick

Patrick Haw Wrote:

I am now wondering if I have alternator issues too. When I put the key in the ignition and turn it, but not the full way to crank the motor, the brake light indicator comes on but nothing else. Should the ignition indicator light come on as well?

It may seem a silly question but I have only had my MGB for a week and I am not sure what is "normal".

Thanks
Richard

gatorbrit Wrote: