Can anyone shed any light on an intermittent fault that I’m currently experiencing on my RM. What’s happening is that on several occasions the horn stops working, but at the same time there is a problem with the automatic gear change in that when in fully automatic mode, both 3rd and 4th gears are engaged prematurely i.e at around 11mph and 16 mph respectively, which is around 3mph less than when they should engage. This actually does make a significant difference in the torque as it's very difficult to get up any speen in 4th when you're only doing around 16mph!

The problem often clears and results in the horn starting to work and the gears changing up from 2nd to 3rd and 3rd to 4th as they should do.

I’ve noticed the intermittent fault with the gears for some while but it’s only recently that I’ve noticed that when the fault occurs, the horn doesn’t work!

It’s all very odd, but any advice and clues to what’s going wrong would be very welcome!

My bus number (if any): RM1699 Eastbourne Regent V 69(KHC369)

Hi Steven

Whilst I can`t help you with your electrical problem I can add another equally bizarre example that bemused those who saw the proof....

How about an RM that drove normally through the gears but could also engage automatic by putting the trafficator on `nearside`. So with it flashing normally the bus could be driven with the gear selector in neutral! The bus was 1871 and it had been in storage at Bus Sales for a while when it came to Stamford Brook (as many did) for pre-sale work to take place. I don`t know enough about electrics to recall how it was fixed but it was sorted quite quickly. Which, in a garage full of equipment and knowledge, is so easy compared to life in preservation.....

Steve
As its an intermittent fault it would suggest dirty, loose or damaged terminal connections. As a start, check the status of all the terminals in the regulator box and control panel, tighten and clean where necessary. It has been known for terminal lugs and screws to have cracked or broken, particularly in the regulator box. Check also battery leads, joints and terminals.

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs

Steve check to make sure you've not got a negative earth, a test lamp (fused) between the positive battery terminal & various places on the body is an easy check. When I was working on old buses a few years back I found a RM with a fault simular to yours & it had a negative earth caused by a recondidtioned starter being rebuilt for a negitive earth system ( ie Titan ). EP valves do not like having a negitive earth & problems will occur.
Neil, i remember that RM with the gear problem well, it acted like a retarder slowing the bus down, that was a long time back how the years have flown past. You should really write the book Neil. Kind regards, Paul.

My bus number (if any): MD 60( getting there, costing a fortune) MD 99( rusty) Hull 411 (oh dear!!)

Thanks for your comments. I haven't had time to check things out as yet but will report back as soon as I fine something. However, it seems as if the fault clear when I turn the side/tail lights on - so it's even more puzzling!!

My bus number (if any): RM1699 Eastbourne Regent V 69(KHC369)