Northern Auto Tech - ECU and Blue & Me Repairs

Technical Power Drain (when driving in the wet/dark)

Currently reading:
Technical Power Drain (when driving in the wet/dark)

Pete145

Pete145

Member
Joined
Jun 2, 2014
Messages
288
Points
85
Hi everyone, I've had a quick look and can't see a thread that specifically covers this, but if one exists please feel free to just point me to it and delete this thread.

It's not often that I drive my car in the dark and/or wet, so it's pretty unusual to have to do both. Over the weekend just gone, however, I had to do just that, and I uncovered a pretty dangerous issue.

When the headlights and wipers are on and the car is braking (engaging the brake lights), the indicators don't seem to work. Even with the wipers switched off there doesn't seem to be enough power for the indicators to work when braking. This is an issue, as it's pretty common to brake into corners that you need to use your indicators for.

I assume that only so much power can be drawn from the battery, and lights plus brake lights plus indicators is just a bridge too far.

Two questions:

1 - Is this normal or do I have an issue?
2 - Is there a fix/mod that I can do to address this?

Thanks in advance!

Pete
 
Hi.

That reminds me of vehicles with 'direct' power : no battery

You brake and the headlight goes out..!




However.. if yours is fine in the warm and dry.. I think you have a moisture
issue.

Where.. ?

Tell us more about the vehicles build ..both spec. And running state ;)

Charlie
 
varesecrazy said:
Where.. ?



Tell us more about the vehicles build ..both spec. And running state ;)



Charlie
Click to expand...



Hi Charlie.

Based in the West Midlands/South Staffordshire.

It’s pretty much a ‘dry car’, fully restored and in good condition. I noticed this issue in the summer, when I last drove it at night (before this weekend) so I don’t think it’s a damp issue to be honest.
 
Pete145 said:
Hi everyone, I've had a quick look and can't see a thread that specifically covers this, but if one exists please feel free to just point me to it and delete this thread.

It's not often that I drive my car in the dark and/or wet, so it's pretty unusual to have to do both. Over the weekend just gone, however, I had to do just that, and I uncovered a pretty dangerous issue.

When the headlights and wipers are on and the car is braking (engaging the brake lights), the indicators don't seem to work. Even with the wipers switched off there doesn't seem to be enough power for the indicators to work when braking. This is an issue, as it's pretty common to brake into corners that you need to use your indicators for.

I assume that only so much power can be drawn from the battery, and lights plus brake lights plus indicators is just a bridge too far.

Two questions:

1 - Is this normal or do I have an issue?
2 - Is there a fix/mod that I can do to address this?

Thanks in advance!

Pete
Click to expand...
If you were running an alternator there would be more than enough electricity being generated to match the consumption of lights, indicators and wiper.

The dynamo has a significantly lower output and relies more on the battery as a reservoir of power when there is a high demand and when at lower RPM.
The situation you describe isn't normal but may be a result of a malfunction (wear?) in the dynamo, poor or dirty connections (including those at the battery) or an undercharged or failing battery.
I'm sure an auto-electrician would diagnose the actual problem very quickly!.
 
When cars are turned off you think that the battery should keep its charge better. But classic cars I think are better fitted with a cut out switch .It saves the battery better because of intermittent use and acts as a theft deterrent .
 
fiat500 said:
If you were running an alternator there would be more than enough electricity being generated to match the consumption of lights, indicators and wiper.
Click to expand...

Just opening this thread up again, as I have recently had to change my battery (I went with the option for a more powerful battery that was recommended in another thread).

The dynamo to alternator upgrade intrigues me as, even with the new battery, the indicators cease working when the headlights, indicators, wipers AND brake lights are all on.

So, to elaborate. Imagine that I'm driving in the dark and wet (not hard during a British winter). Lights are on and working fine, wipers are on and also working fine, indicators work fine UNTIL I deploy the brakes, and it's at that moment that the indicators go out, as power is diverted to the brake lights. When I lift off the brakes the indicators start to blink again!

To my question, would the retrofit of the alternator fix this and provide enough power to all of the bells and whistles (lights and wipers)? I see that some of the usual web-shops stock a conversion kit, which include the new tin-wear, which I gather is a complication.
 
I am not an auto electrician but I believe that the standard flasher unit relies on the voltage to activate it but if you go for an electronic flasher unit they will run on far less power but thumbs up to you for driving in these conditions :)
 
Pete145 said:
Just opening this thread up again, ...................................
The dynamo to alternator upgrade intrigues me as, even with the new battery, the indicators cease working when the headlights, indicators, wipers AND brake lights are all on.
.....................................
Click to expand...


something that has not been mentioned that affects many "classics"...
"High Resistance" this is where earth straps and good contacts everywhere are important..... a High Resistance will not stop something from working... but will require a lot more "current" to do the job, hence more drain on the battery....

As you are midlands/South Birmingham....
you could talk to "Powerlite" in Brierly Hill
I have been talking to a fellow Prototypi owner about the idea of having a "Dynalite made for a Fiat 500.. basically a Alternator that looks like a Dynamo.... it would not require any tinwear changes and retains the "Original"look.... so the cost is balanced.... the original regulator can be used as a junction box...

They are an expensive bit of kit... but come with a comprehensive warranty (Lifetime - but lifetime of what I always ask... after all a TomTom satnav has free lifetime maps.. but that's only for the expected Lifetime of the Unit not your lifetime....)
 
Pete145 said:
So, to elaborate. Imagine that I'm driving in the dark and wet (not hard during a British winter). Lights are on and working fine, wipers are on and also working fine, indicators work fine UNTIL I deploy the brakes, and it's at that moment that the indicators go out, as power is diverted to the brake lights. When I lift off the brakes the indicators start to blink again!
Click to expand...

I would check the ground (earth) and the general state of the wiring terminals and bulbs and bulb contacts in the rear lights; the brake lights may be shorting through an indicator bulb. It might also be worth looking at the cleanliness of the fuse contacts and the ends of the fuses.

Pete145 said:
To my question, would the retrofit of the alternator fix this and provide enough power to all of the bells and whistles (lights and wipers)? I see that some of the usual web-shops stock a conversion kit, which include the new tin-wear, which I gather is a complication.
Click to expand...

If the problem is bad contacts/earthing, obviously no point fitting an alternator to cure it.

But my experience is that an alternator is a very worthwhile upgrade. To give you an idea how fickle electricity is; my alternator works really well, but since I fitted a USB socket, which also acts as a voltmeter, I was getting a reading of around 13.5 volts, which was plenty. But since messing around with connections, cleaning them and using di-electric grease, the reading has gone up to a more correct 14.1 volts. When I turn on the lights the volts go down to 13.4. The alternator seems to easily cope with my ever increasing array of electrical accessories.:eek:
 
Afternoon Peter;
A chat with 'Dynalite' might well prove worthwhile, but I expect that if they were prepared to try and 'Alternaterise' a dynamo, you would have to leave the dynamo with them some time. I have spoken to them in the past regarding just this problem and they were fairly negative; I think the answer was "no, we can't do it". But, if you were able to leave a dynamo with them (possibly a spare 2nd hand one), they might be prepared to 'have a go'. It could be beneficial for a lot of 500/early 126 owners.
 
You must log in or register to reply here.

Similar threads

R
Technical Brake lights work tail lights don’t
Replies
8
Views
234
bugsymike
B
S
Technical what size allen key for the gearbox oil drain?
Replies
8
Views
1K
Goldnrust
G
C
  • Question
General When did the front badge change?
Replies
9
Views
758
chenry
C
R
General Considering a Very Long Drive in a New to me Fiat
2
Replies
29
Views
746
Cornish Ian
C
jolly500
Technical Fitting the plate over the generator
Replies
7
Views
308
wingless
wingless
Back
Top