Wiper motor and heater fan / fuel gauge issue

[twostrokecharlie]

I own a recently re-furbished 1965 Traveller which I recently purchased, with bills for extensive professional refurbishment I assumed little or few problems. However, travelling on a recent rally in rain noted that the wipers occaccionally stopped, then intermitentally started again having left switch alone, I also noted the fuel gauge went to zero fuel indication. Playing around with switches etc (note on a timed rally at the time) noticed if I switched the heater fan on the wipers stopped and fuel gauge to zero. The voltage gauge showing a fluctuation in voltage drop, if switched fan and wiper off things went back to normal. Wipers back on and switched lights on the wipers occassionally stopped then went OK again. If wipers only they would intermittenly start then start again. Each stoppage of either fan or wipers showed a negative volt drop on gauge but as a spike rather than a smooth simple drop. Is there a surge protector fitted to the traveller that could cause this problem or is it unique? I have noted a few improvements required that I thought should have been picked up in the renovation but there you go.Any help would be gratefully received.

[Steve Phillips]

First thing to look at would be earth connections,

Not saying that’s the answer to all your problems but poor earth connections will give you lots of interesting electrical gremlins,

Make sure all the earths are screwed/bolted to a good ground,

it might be worth removing as many earths as you can find, (one at a time) clean the ring terminals and the body where that terminal attaches using something like scotch-brite and apply a tiny smear of copper slip between the screw and the body before re attaching,

As I say might not cure all your problems but a lot of classics that come in to me with electrical issues turn out to be bad earths.

[geoberni]

Everything you're describing is from the fuse with the green wiring, i.e. only live when the IGN is on.
As there will be several different earth points involved, it's almost certainly a volts drop at the fuse, as the only common point. That fuse also feeds other things, such as the Indicators & Stop Lamps, plus anything else that has been added to the car to have an IGN supply.

In very simple terms, you can have a dirty fuse connection and only one item drawing power (e.g.wipers), and you won't notice it.

But once you add other items to the circuit, which are going to be in parallel to the original item, but series to the dirty fuse connection, then you start altering the relationship of Ohms Law.
Net result in Layman terms, weird poop starts happening; including the 'allocation' of the voltage between the resistance of the intended items, and the resistance of the dirty fuse holder. This can result in the available voltage at the Wiper Motor being perhaps 10v or less.

I hope that hasn't confused you.

[svenedin]

Everything you're describing is from the fuse with the green wiring, i.e. only live when the IGN is on.
As there will be several different earth points involved, it's almost certainly a volts drop at the fuse, as the only common point. That fuse also feeds other things, such as the Indicators & Stop Lamps, plus anything else that has been added to the car to have an IGN supply.

In very simple terms, you can have a dirty fuse connection and only one item drawing power (e.g.wipers), and you won't notice it.

But once you add other items to the circuit, which are going to be in parallel to the original item, but series to the dirty fuse connection, then you start altering the relationship of Ohms Law.
Net result in Layman terms, weird poop starts happening; including the 'allocation' of the voltage between the resistance of the intended items, and the resistance of the dirty fuse holder. This can result in the available voltage at the Wiper Motor being perhaps 10v or less.

I hope that hasn't confused you.

Wonderful diagnosis and explanation!

[twostrokecharlie]

great explanation of what is happening but has new fuse box and replaced the fuse just in case, am I still missing something? took the speedo out today to view the voltage regulator ( could be called something else) which has 2 lots of conections and located at top of speedo on back. I am sure I heard some weird electrical noise when wiper/fan/lights were switched on and unit appeared to go warm. Is this normal?

[geoberni]

great explanation of what is happening but has new fuse box and replaced the fuse just in case, am I still missing something? took the speedo out today to view the voltage regulator ( could be called something else) which has 2 lots of conections and located at top of speedo on back. I am sure I heard some weird electrical noise when wiper/fan/lights were switched on and unit appeared to go warm. Is this normal?

I can't vouch for any strange noise, as my car predates that being fitted, but I can tell you how it works.
The item you refer to is the Voltage Stabiliser, which is needed by the latter style Fuel Gauge. It requires a stabilised 10V to power the fuel gauge system.
The original Smiths Stabilisers are a bit like the classic indicator Flasher, they just operate very much faster; inside is a bimetallic strip, an insulated heating wire coil, and contact points. So yes I imagine it'll be a little warm as it's the way it works.
But that is only feeding the Fuel Gauge, the side with one connection to it.
The side with 3 cable is the input from the IGN Sw and then 2 pick offs to go off to the Wipers, Heater Blower and the Oil Warning light.
That side is simply a junction point.

[twostrokecharlie]

thanks geoberni that information is very helpful but would a faulty voltage stabiliser cause the problems that I am having ie wipers intermittenly starting and stopping where when stopped the fuel gauge stops working and fan motor acts in same way as wipers?

[geoberni]

thanks geoberni that information is very helpful but would a faulty voltage stabiliser cause the problems that I am having ie wipers intermittenly starting and stopping where when stopped the fuel gauge stops working and fan motor acts in same way as wipers?

I can't imagine it, stabiliser faults tend to affect only the fuel gauge, but I guess anything is possible.

I'd certainly have a good look at, and clean up, the terminations on it.
I'm metaphorically kicking myself for not realising that the connection on the Stabiliser is also a common point for all the systems that you're having a problem with, in addition to the fuse.
So a good clean up of the contacts there would be a bad thing.


You might have a read of this Minimania page, it's an American site, but it has some good fault diagnosis on there which saves me thinking of it all and writing it up.
https://www.minimania.com/Smiths_Voltage_Stabilizers

[twostrokecharlie]

Hi geoberni, with your help problem solved due to incorrect wiring on voltage stabiliser. Pulled off a wiring diagram and the issue was so obvious I could kick myself for not seeing it earlier. All said systems of fan / fuel gauge / wipers / voltage gauge (after market) joined together. A quick juggle about and new wire from volt gauge to fuse box has fixed the problem, well done and thank you

[geoberni]

Very glad you sorted it....
The person you brought it from, or their refurbisher, obviously couldn't follow a wiring diagram...

It's a very good job you posted this on here; had you posted it on the facebook group, there would be probably a list of comments about 30-50 long, with all manner of bright ideas, some of them serious, some facetious, and quite a few absolutely bonkers...which would have just driven you crazy trying to sift through them.