An MGA drove in a few weeks ago with a concern about a slow, hard start after a normal drive. The owner was afraid to take the car anywhere because it would behave in an ornery ‘Englishy’ fashion at some point and leave him stranded.

This particular MGA was a late model version and had been restored meticulously, the doors were arrow straight, the fender welting fitted evenly and virtually everything under the hood was in the right place and just ‘shiny’. A really nice example and it was a red one!.

I began my career as a tech when MGB’s were new and the MGA models still belonged to original owners so this car looked like a fun one to check out.

After looking this it over, I let it warm up and after a 10 minute run shut it off and was given a smelly 1 minute “after run” as a ‘…just try to fix me’ greeting.

Attempting to start it was exactly as the owner described…a very hard turnover with only a few revolutions with the engine clearly struggling.

Battery voltage was perfect (converted to a single 12 volt that nicely fit in the tray) as was battery health. I tried a ‘field test’ using a jumper cable from the negative cable to the engine and the engine crank speed was restored.

No clean ground you say?...the braided metal strap that uses the body as part of the electrical circuit was clearly in place and tight on the left motor mount. It was just bolted from a lower body position to another lower body position.

In other words the ground strap never was bolted from the body to engine so the starter never received proper current. A relatively quick fix and the start system was restored.

As for the after run, a check of the timing found it significantly retarded in order to get the car to run on today’s low octane fuels. Adjustments of the carburetors leaned the mixture and helped limit fuel availability after shut down.

Advancing the timing allowed a very smooth 700 rpm idle though a pretty sharp engine ping which can be addressed by octane booster. This car drove nearly the same as those I recalled 30+ years ago!

The simple MGA engine grounding has been replaced on newer autos with all sorts of configurations replacing the lowly single strap to a dozen small ground straps from the engine to body and other components (fuel tanks have grounds) to ensure current flow under any condition. I’ve even seen dash gauges with their own small dedicated ground strap!

This Battery/Electrical system technology is an example of a big change from old to new cars that really impacts automobiles (and owners) today.

Battery systems definitely have become much more complex than the MGA’s original twin 6 volt batteries. Most cars use high efficient 12 volt versions and a number of new cars have 2 full size 12 volt batteries - a Start battery and a Main system battery.

Essentially these engines turn over from the Start battery then switch to the Main system battery for running and system support. The Start battery is then isolated other than receiving charging voltage.

Alternators are quite high output. From the MGA’s 20 amp generator, the Rolls-Royce Phantoms use 2 water cooled Alternators of high amp ratings to keep the system at correct voltage. The Bentley GT uses one large water cooled Alternator which requires powerplant removal to service.

Not generally known is that in the last 10 years, wiring on modern cars had become so complex that a harness might be nearly 2-3 inches thick with hundreds of wiring branching in multiple directions. As could be expected, diagnosis of a wiring problem became just as complex.

Voltage levels are now replaced by Signal measurements in newer car electrical systems. The signals across these wires also became more sophisticated especially with the addition of entertainment systems. So here is the manufactures fix.

CANbus (Controller Area Network) and Fiber optics. If you have never heard these terms, you are not alone but will want to get acquainted with them. (the ‘bus’ part of CANbus is the term describing the transfer of data- think electrical current riding on the bus)

A simplified image of a CANbus system might be this - imagine a single wire in a loop with 10 computers connected at even intervals along the loop. The wire can transfer multiple signals for all ten computers on the loop but each will only act upon a signal it can understand and ignore the signals meant for the other computers. That’s a Controller Area Network or CAN.

What’s the point of CANbus? …now a wiring harness can be much smaller and transfer huge amounts of electrical info…but here is the rub. Diagnosis of a CANbus system can only be performed with equipment designed to read and interpret it and by a Technician who is trained to use them. A volt meter or test light like used with the MGA just won’t cut it.

Some cars are equipped with 70 or more computers, CANbus architecture is the only way for all to ‘talk’ to each other fast enough for owner/driver expectations. Think of the lag time we all experience waiting for a web-page to load. Would you tolerate a delay in turn signal use or window operation?...not likely. Most people won’t and old wiring styles cannot keep up with the switching systems now made.

Sometimes this is driven by the manufacturers of switches and computers. Car makers often just go to supplier like Bosch or Lucas or Delco and ask for a component to fit a certain function. They will be offered an off-the-shelf existing part or may have the supplier make up a new version including design.

Which is cheaper?...the existing off-the-shelf part and cost of manufacture often is the deciding factor.

I have had owners tell me “…my car started slow this morning and the windows dropped down, the Air Conditioning works funny and the sunroof won’t open…this car is junk…!”

What happened here is that the CAN system was low on support voltage and cancelled or put on stand-by specific systems allowing the car to start. This is a design feature to make certain all available battery power is used for start-up, everything else is considered non-essential.

The fix is to restore low battery voltage either by charging or battery replacement.

Now if this happened to a 1 or 2 year old car, you might ask why should a battery be low? If the annual mileage is low or drives infrequent, the battery might not be consistently charged and this car would be a candidate for a battery maintenance charger.

Why is low mileage an issue? Batteries receive charge only when an engine is running and driving. Engine rpm restores the juice used in the start-up cycle then continues to bring up the battery voltage to the correct level. CANbus systems require reliable voltage levels which is why most CAN cars equipped have heavy duty alternators.

Low miles might be 7-10 mile trips or a short drive only a few times a week. Sounds like it should be adequate but for a car driven 5000-7000 yearly with a complex CANbus system, it simply may not be enough.

Don’t be surprised to find out your Battery(s) may have to be maintained to ensure steady voltage all the time. A drop of .5 volt can cause some features to become dysfunctional with no real prior warning or indication. Short trips and low miles can be responsible.

Also, when you car is turned off, CAN systems periodically ‘wake-up’ and confirm all systems are in ‘sleep’ mode. Each wake-up cycle takes a little current and after a week or so of no driving battery voltage can erode enough to cause issues.

Cars not driven much should have a battery maintenance charger. Yes it’s true - batteries now might need their own ‘maintenance’ in the form of a dedicated wall current plug-in charger that is left on the car when parked for extended periods.

These chargers bring voltage up to a ‘healthy level’ the go to sleep on their own. Periodically the charger ‘wakes-up’, checks on battery condition and either continue charging or moves to a ‘float charge’ mode. This sequence is repeated to maintain battery voltage.

The CANBus technology is now migrating to many other products, even motorcycles are equipped with CAN systems. Throttle cables are replaced by twistgrips that send throttles a signal to set positions – ride by wire!

Another way to transmit info is by light using Fiber optics, a thin ‘optic’ cable made of glass or fiber that transmits data. Phone companies have used fiber optics for years. Like CAN systems these need special equipment to read the data across the optic line and a tech trained to use it.

Fiber optics in the automobile industry are primarily used on the sound and entertainment (TV) systems. The light pulses down a cable and is captured by modules along its run. The light is kept within the optic core by total internal reflection and the pulses are very fast, required for visual systems and accurate.

Fiber optics are immune to interference from magnetic sources, unlike electrical systems which can have signals corrupted by current from a nearby wire. This is important in the auto environment because the entire car has wiring from end to end with nothing too far away from each other.

A single optic cable can carry the same as inches of thick wiring so why aren’t optics used everywhere? One answer is that the infrastructure to test fiber optics is not yet wide-spread at all Dealers or Independent facilities so the technology is not practical on a wide scale-yet.

Vehicle makes like Mercedes-Benz, BMW, Audi/VW, Volvo have used Fiber optics in their Entertainment (the Euro term is ‘Infotainment’) systems for some years and now have this technology installed in the Engine Management systems to replace hard wiring.

Fiber optics can be bundled just like wiring for complex systems. Fiber lines are not as easy to repair if damaged so if a harness needs repair, the end needs to be ‘cleaved’ precisely or an entire harness needs replacement, no soldering here!

Fiber optics can be used to light instruments too! A single bulb at the beginning of a optic ‘bundle’ can be routed feet away and still provide pinpoint light.

What’s the auto world coming to? …well in a word – it’s ‘Technology’

Notice I did not say advances in technology. Whether we are ready, or even want to be ready, the auto industry will continue to use newer technology to meet buyer demands for features. The choice of older technology products is up to the buyer as well, as long as there is a support network of shops.

So what do MGA’s, Batteries, CANbus and Fiber optics have in common? Other than electricity going from one component to another and a battery supplying power and both can have no-start problems - they are Technology night and day. Both occupy a place in our world, just on different levels.

This new technology complexity is one reason why the 48 year old MGA is still on the road along with other vintage autocars. They are relatively simple and a dedicated owner with the enthusiasm to restore it, can keep these great classics going and going.

The jury is out on how long CANbus equipped cars will survive or what a practical service life they can give. Unless an owner is an electrical engineer, most will not have the skill or equipment to even read the simplest CAN signals. No one is quite certain how long components, the various computers or even the wiring will last.

New cars now require highly specialized techs with the required equipment to perform diagnosis and repairs. Even one car to another are so dissimilar a tech cannot easily transfer diagnostic concepts or test equipment. It truly is another age emerging when we speak about car repairs.

Drive safe – visit and support a shop like Zak’s!