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MG MGB Technical - High Beam Problems

I have a 1974 MGB GT - chrome bumper - that has developed a problem with the high beams. The low beams are fine and come on with the switch but when I was driving along a long dark section of highway and pushed the high beam switch all went dark!

I have tried flicking them on and off but still only the low beams work. I notice that the high beam indicator lamp also does not come on. Has anyone had the same experience? I have not pulled the steering column cover off to check the switch and wires yet but did check the fuses and all seem to be OK and nothing else appears to be out of operation.

Brian
Brian

Brian. I had a similar problem with my daughter's car. Traced it to a bad connection at the front of the car. Cleaned and reconnected the wires and all worked well. Do not remember if the high beam indicator light came on or not. Was doing about 55 on a rural road when I switched to high beams and lost headlights, so did not worry about it at that time and never bothered to re-check. You might check out all of the connections and use a test light to see if power is getting to the line going to the high beams. If not, it is the wire or the switch. If you are getting power, the problem is between the line from the switch and the lights. Les
Les Bengtson

I agree with Les.
I've found over many years, many MGBs and many miles that almost all headlight wiring problems are caused by corrosion in the bullet connectors at the front of the car. Same for indicators.
You need to go through the lot, taking each one apart, sanding the males lightly, squeezing the females a little to make a closer fit and then spray with WD40 before re-assembly.
It's an easy little job to do on an annual service.
Marc

If the tell-tale on the dash didn't come on either, and if it used to, then the dip-switch itself or possibly the multi-plug by the column will probably be the cause.

Does the headlamp flasher still (if it used to) work? If so it is the switch, if not it is probably the plug or wiring up the column.

Only the headlamp flasher is fused (purple circuit, bottom fuse), the normal headlamps, dip and main, are not.
Paul Hunt

I had the same problem, it was the double bullet connectors behind the grille. They were well beyond sanding, just replace with a few pence worth of new connectors.

Tim.
Tim Jenner

Brian - I had this exact problem as described on my '69, after trying all the usual wiring and connector first aid, traced it to the column-mounted switch itself which I replaced and all was right again. This is a rather delicate multi-function device [which on the 69 also includes the horn contact] and somewhat pricey too, although the later ones as yours are more reasonable, so try the low cost solutions first.
Jon Sjoberg

I have just bought a '79 MGB, with an obviously broken dimmer/horn switch. I have the new part, but am having a time removing the steering wheel to replace it. The service manual seems to reference a different type of steering wheel hub, with several bolts that are removed and thereby allow a wheel puller to be attached. Mine has only a large nut on the spindle, and the splines are stuck.
Is there a special tool/ technique for removing the wheel?

Craig
C. Woloshyn

Brian,
I have the same problem on my 73 GT. In my case it is the switch, the connection for the high beams has broken off. I tried soldering it back together, lasted about a week before braking again. One of these days I will replace the switch. On mine I can see the broken connection with out pulling the cover, just look through the hole where the stalk comes out.

Scott
73 B GT
Scott

If you are lucky a simple adjustment to the switch may be all that is needed. Remove the column cover to reveal the switch. With the battery disconnected, carefuly clean the copper contacts of the switch. Observe the functioning of the switch contacts. Do they make good contact when you move the lver in and out? If not, try bending them ever so slightly so that they do. It worked for me.
Andrew Blackley

Craig:

You don't really need to remove the steering wheel to get the column shroud off. Just undo the four screws (watch out two of the screws have loose nuts) and push the shroud slightly back & away from the wheel. They should come out at an angle. This makes replacement of the stalk switches easier.

Good luck,

Luis
Luis

Craig. I have never been able to remove the shroud without removing the steering wheel. There are two cross screws, towards the front that are engaged from the left hand side, one above the other. There are two smaller screws forward, near the dash. They are engaged from the left side for the left hand screw and the right side for the right hand screw. The steering wheel is often glued to the splines by old grease, oil and dust. Remove the nut, spray it with good penetrating oil and let it sit. Sometimes, you have to do this for several days. (ZEP-45, available from some mechanics, is the best penetrating oil I have ever used. Liquid Wrench is also good. Avoid WD-40 as it leaves a sticky residue as it evaporates and will cause more problems.) When you are feeling strong, put the steering wheel nut on for about two full turns and tug the steering wheel side to side, up and down, always pulling it towards you to remove it. Sometimes, a rubber mallet on the back side helps. Others have made up field expedient forms of steering wheel pullers which will work with the standard RB wheel. Rarely, the steering wheel is well and truly stuck. I have only seen it one time and it was removed by professionals who dropped and removed the steering column, removed the shroud and removed the wheel. Wheel was damaged beyond use. It happens. When you go to put a steering wheel on, clean the splines on the shaft and inside the wheel hub. Then, use anti-seize, lightly, on the steering column splines. Makes the next time much easier. Turn signal switches last about three years. Did that when they were new, do that now. POS design. So, you will have to remove the parts again in a few years. Make it as easy as possible by taking your time and doing it right the first time, then cleaning and anti-seizing afterwards. Les
Les Bengtson

This thread was discussed between 21/02/2002 and 25/02/2002

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