Here's a question for the electricians among you.Other than the immobilizer switch and the join in the main cables underneath the offside rear seat are there any other joins in the cables that run to the starter motor?
Recently I have been suffering what sounds like a lazy starter motor but have removed it and had it checked out and everything was fine.I cleaned up the connections in the immobilizer and the join under the seats but still she turns over painfully slowly.
The batteries were next and all duly checked out as OK.
Is there anything to be gained by moving the batteries forward?
With winter just around the corner I would like to fix this soon.

My bus number (if any): RML 2478

Graham

The battery cables run via the charge control panel which is behind the large cover on the bulkhead inside the driving cab, here you will find the main starter cables. Its worth a good check of the main cable terminals here and the start relays & alt field relay are located here. Ed

I've got the same problem with RML2532 and RML2567 in Germany!

On 2532 I fitted a new starter a year or so ago; new 721 batteries; still the same problem. Removed and cleaned the isolator switch; same problem!

I'd already checked the cable connections, so reckon it must be the leads from the battery to the isolator switch as it starts every time the boost pack is connected via the cowbell connecter.

As for 2567, it could be anything, I haven't had time to check it out, but it appears to be the same problem.

I'm going to fit new battery to switch leads next week, let's see if that'll cure it. It seems to be a common problem on quite a few RMs at the moment.

My bus number (if any): RML2532 and others

One of the problems we encountered on a couple of RMs a few years ago is the poor resistance readings on some of the heavy load cables.

On the RM it was original cables and whilst the bus was very well kept and all the terminals were clean and uncorroded, the elements and non regular use had caused almost every cable on the bus to corrode internally.

In some places the insulation had failed and was easy to spot. In others the insulation looked OK but had small cracks and had become porous and the damp atmosphere had led to moisture ingressing the cables and damaging the performance of the cables.

On the RML which was a refurbed one the cables were of really poor quality offering poor resistance readings.

The owners bit the bullet and we had new cables to the highest quality made up by a specialist HGV electrical factors.

All the crucial wiring was replaced and it took quite some man hours to do. But both buses were like new afterwards, starting easily, charging properly, the lighting was bright, the cab heater ran fast enough to demist the screen,the gearboxes worked as they should and as far as I know, are still trouble free.

I'm inclined now in hindsight to think that double insulated cables would be better for buses that are in preservation or irregular use.

If it is a refurb bus with copper cable and the terminal lugs are crimped or soldered properly they should be okay for years without any corrosion taking place throughout the length of a cable run assuming the insulation is in good condition. However if the battery cables to the cab are aluminium then that is a different story and corrosion is likely given the operating conditions and general less rugged capability of aluminium cables. Problems of high resistance are more likely with aluminium cables than with copper especially after a long service life.
Jacks comments reveal that poor quality cables were used on the refurbs, was this the main problem or poor connectivity due to bad workmanship at the time of the refurbishment program. From what I have seen so far on the buses I have owned, the wiring was not carried out by a skilled auto electrician, basic connections made with poor termination. When buying electrical cable it is best to purchase the more expensive cable than a cheaper inferior one with less copper content, it really is a case of you get what you pay for.

Thanks to the 2 Roys,Ed and Jack.
My fitter had suggested moving the Batteries forward which I guess was his way of saying lets cut out that length of cable as we have tried everything else.
Is it possible to temporarily move the batteries and connect them with something like jump leads to rule out the cables once and for all.My bus seems to have undergone a half hearted refurb,some stuff changed and some not.The cables are copper and do appear to be in good nick but as Jack suggests the cover could be hiding a multitude of sins.I have owned her now for 9 years and this is the first time she has let me down as far starting is concerned so I really can't complain,stopping now that's another story altogether.

My bus number (if any): RML 2478

I suggest you try jump leads from the batteries to the cable join under the offside 4 seats. that "should" prove whether the fault is on the battery leads to the isolator.

As for stopping, either of us roys would be glad to help and rectify the problems which usually involves a complete strip-down of the braking system to free up rusted rollers on brake shoes, check accumulators, check line pressures, adjust hand brake linkages etc., usually about 2 days work when we have all the facilities to hand.

My bus number (if any): RML2532 and others

So finally this last weekend we got around to doing something about the poor starting problem.The cables running from the batteries and Isolator switch to the front of the bus all appeared to be in first class condition but on cutting back some of the insulation it was clear that the cable had corroded within the covering,so what looked good on the surface was not good underneath.Faced with the prospect of spending a fortune on new cable and spending hours fitting it we took the easy option and moved the batteries forward and now have cables that are probably 20ft shorter than they used to be.End result is a bus that starts quicker than my car a heater blower that sounds like Concorde on take off and interior lights that wouldn't be out of place in a sun tan parlour.There's nothing worse than hitting the starter and getting that sinking feeling as you realise "She ain't going to start".Anybody want to buy a pair of well used jump leads?as I hope my starting problems are over.

My bus number (if any): RML2478

so pretty much the same as we encountered with other RMs.

But Graham, I think you need to think seriously about moving the batteries other than to verify the problem.

Batteries of a vehicle this size with the kind of amperage and load draws can produce a lot of sulphuric acid vapour.

It is toxic and can cause many side effects in people. Not something you should risk even if it's just yourself with the vehicle.

Secondly, the batteries vapour can be explosive. We already know of an RML destroyed by fire in the last year from displaced batteries.

The RM/ RML battery compartment is ventilated but also sealed with a fireproof coating and the crates were designed to protect the batteries as best as possible in the event of a collision. The layout of all the buses ancilliaries are also balanced to keep the unladen weight as even as possible. There is a bit of latitude for an extra fuel tank, but the tank is sealed and vents are external unlike batteries which have to vent directly.

The only safe and prudent solution is I'm afraid, to replace the corroded cables completely with the best quality cable.
Expensive but at least now you know the cause and how it should be when it has not got the resistance failings.

I'm sure you are correct in what you say Jack and I think that in the back of my mind I knew this would not be a permanent fix.
I will be replacing the cable in the new year but for the time being given that the old girl will not get a lot of use due mainly to the weather and road conditions in my part of the country I will just be happy to start her and move her around the yard.Just a thought but is it not possible to buy sealed batteries these days?Would this get around the fumes problem?
Many thanks for your help and advice.

My bus number (if any): RML2478

As long as it's helpful to you Graham, No problem.

To just shunt the bus about and so on I don't think there's going to be a problem. It's longer journeys and carrying even a few passengers where it becomes a risk.

Sealed batteries are still vented. There are also batteries with acid gel that won't leak out if the battery is displaced.

There are some that are safer still, but they are seriously expensive, far more than the best cables will cost.

But as a short term quick fix at least this will give you time to shop around and source good quality new cables.

You might want to try and clean all the electrical contacts and spray them with Jenolite electrical contact cleaner.
It's a mild acid and used correctly works very well.
Then a spray of wd 40 on the cables which creeps a bit and gives a bit of protection to the wiring.
There is also a commercial battery terminal spray coating. It is green in colour and seals the exposed terminals and connections and stops moisture creeping up the cable filaments.

Here's something Really Useful sent by my son regarding electrical problems:

The following just about sums up old and worn electrical components as fitted to British cars pre 1960. Today it needn't be a problem.

Have a read.




Positive grounding depends on proper circuit functioning, which is the
transmission of negative ions by retention of the visible spectral
manifestation known as smoke".

This has been referred to as the smoke theory as when the smoke comes
out its finished, cooked or done for.

Smoke is the thing that makes electrical circuits work. We know this
to be true because every time one lets the smoke out of an electrical
circuit, it stops working. This can be verified repeatedly through
empirical testing.

For example, if one places a copper bar across the terminals of a
battery, prodigious quantities of smoke are liberated and the battery
shortly ceases to function. In addition, if one observes smoke escaping
from an electrical component such as a Lucas voltage regulator, it will
also be observed that the component no longer functions. The logic is
elementary and inescapable!

The function of the wiring harness is to conduct the smoke from one
device to another. When the wiring springs a leak and lets all the smoke
out of the system, nothing works afterwards.

Starter motors were considered unsuitable for British motorcycles for
some time largely because they consumed large quantities of smoke,
requiring very unsightly large wires.
It has been reported that Lucas electrical components are possibly
more prone to electrical leakage than their Bosch, Japanese or American
counterparts. Experts point out that this is because Lucas is British,
and all things British leak. British engines leak oil, British shock
absorbers, hydraulic forks and disk brake systems leak fluid, British
tyres leak air.

Therefore, it follows that British electrical systems must leak smoke.
Once again, the logic is clear and inescapable.

In conclusion, the basic concept of transmission of electrical energy
in the form of smoke provides a logical explanation of the mysteries of
electrical components especially British units manufactured by Joseph Lucas, Ltd

And remember: "A gentleman does not motor about after dark".

Joseph Lucas The Prince of Darkness 1842-1903


The Lucas motto: Get home before dark.

Lucas is the patent holder for the short circuit.

Lucas - Inventor of the first intermittent wiper.

Lucas - Inventor of the self-dimming headlamp.

The three-position Lucas switch--DIM, FLICKER and OFF.

The other three switch settings--SMOKE, SMOULDER and IGNITE.

The Original Anti -theft device - Lucas Electrics.

My bus number (if any): RML2532

Roy
That is brilliant.
Never a truer word spoken in jest.
During the course of my working lifetime I fell foul of so many of the problems mentioned.I still have a great deal of respect for batteries after witnessing a young man checking the [water] level by putting a lit match to the opening because he said it was dark and not easy to see!!!.The resulting explosion was only drowned out by the noise made when he jerked backwards and banged his head on the bonnet.He was rushed to A&E in the back of an Austin A35 van and for years after he refused any job that involved Batteries or jump leads.

My bus number (if any): RML2478

From my time on LT, here`s some more examples of how batteries bite back.

A conductor at Stamford Brook complained about fuming batteries so bad it was making his eyes water and he couldn`t stand on the platform because of the awful smell. That was good enough reason to run the bus into the garage and should have been enough info for the Running Shift to treat the situation with caution. So a guy who always had a `roll - up` lodged in the corner of his mouth boarded the bus, opened the battery compartment and peered into it. The resulting explosion blew him backwards off the platform but not before he was showered in hot acid. The multiple marks on his face took months to heal and he was so lucky that his eyes survived.

A West Indian Night Foreman at Ash Grove was inspecting the batteries on an RM from the outside access. As he knelt down he slipped on a patch of oil and as his arm flailed out his very chunky metal watch strap touched a terminal. The effect was like a branding iron on a horse except that it turned the burnt area white! Months after the incident the imprint of the strap was still visible - in white!

If I remember correctly, an urgent modification was made to DMS`s in their early days to better ventilate the battery crate which was under the lower deck floor at the bottom of the staircase. An upper deck passenger alighting dropped a lit cigarette which rolled into and down the gap at the edge of the crate. The explosion was such that the screwed down cover shot upwards and actually dented the lower deck ceiling! I think it was DMS 38.

I`ve always had these incidents in the back of my mind when I touch batteries!

Haha I have seen the smoke theory before, years ago in a Landrover magazine. Think it was written by an American Landrover club actually.

Batteries are risky things. I've seen one blown up like a balloon due to a blocked vent. Also careless use of tools leading to badly burnt hands. Rings make amazing conductors.

Treat batteries with respect. They can hurt you.

My bus number (if any): RM531

I mentioned the subject of fumes from batteries accidentally com-busting to the garage that service my car and the answer came back that I should probably change the Merc as the batteries are under the seat,it seems Citroen also place batteries under drivers seats.I can see the Insurance claim form now asking and how did you get these burns on your buttocks?

My bus number (if any): RML2478

Exploding batteries sounds a better excuse than a visit to Mistress Lindi!!

Yes, it's done the rounds, and I suspect DID come from the USA as there's quite a thread about it and other theories about old British cars!

DMS38 was the first to run in public service on the 220s many years ago, but I digress...

My bus number (if any): RML2532

As roy has said on many occasions, only those trained correctly should do the job. You wouldn't, for example, find me running a bus service so perhaps only electricians should work on batteries and wiring.

My bus number (if any): Rml 2276 m1001 t806

Hi David
Yes I agree totally which is in part why I felt confident enough 9 yrs ago to buy the bus.Over the years I spent working as a commercial fitter I made friends with so many people who have helped me out when specialist knowledge is reqd.These are the type of people who when I ask how much is this going to cost it usually gets the answer of "You keep the tea coming and that will do"Friends like these are invaluable when you run older vehicles.I guess what I'm trying to say is the job was carried out by a qualified "Sparkie"assisted by me on the teapot.I'm afraid I'm one of those people who all to often say I've done so and so taking the credit when basically all I've done is assist.

My bus number (if any): RML2478