negative earth conversion problem

[timetraveller]

hi all

hoping someone can help me out

today i did the negative earth conversion as per the technical data on this forum....excellent info by the way and no probs converting however my horn has stopped working and the fuel pump has become noisy and clicky
the fuel pump is a hardi unit and its the original factory horn
do these components need replacing for negative earth items now ????

thanks
neil

[Declan_Burns]

Neil,
The positive terminal on the Hardi pump is to the front of the car and they are noisy. Fit 2 M6 anti-vibration mounts and that will solve the problem-see pic below. The horn problem could be a bad earth.[frame][/frame]
Regards
Declan

[mike.perry]

The horn should not be affected, possibly co incidence. The horn should have two wires so you could try swapping them over.
You can test the horn with a straight connection to the battery and also most horns have a central adjusting screw

[bmcecosse]

The points on both dizzy and fuel pump MUST be cleaned/dressed/re-set when the polarity is reversed. Horn should not be affected - possibly the fuse has blown.

[timetraveller]

hi
again this seems to be a bit of a problem of half information
ive followed someones technical info on converting my car to negative earth but there is no mention of 'MUST' resetting the points on the distributor and fuel pump and i also suppose the heater fan will be running backwards as well...
so how do i clean/dress and reset the points
thanks
neil

[Declan_Burns]

Neil,
If you have the later style heater you should reverse the polarity. This is a cross flow fan with inclined blades and has an arrow on the impeller (difficult to see when the heater is in the car) showing the direction of rotation which is clockwise when looking at the fan inlet. This is often forgotten and changing polarity changes the direction of rotation on a dc motor.[frame][/frame]
Regards
Declan

[timetraveller]

Neil,
If you have the later style heater you should reverse the polarity. This is a cross flow fan with inclined blades and has an arrow on the impeller (difficult to see when the heater is in the car) showing the direction of rotation which is clockwise when looking at the fan inlet. This is often forgotten and changing polarity changes the direction of rotation on a dc motor.
Regards
Declan

hi declan
yes its a later heater as its a 71 traveller
i read in another post to stick a bit of tissue paper over the demister vent and turn the heater on
obviously if it sucks the tissue in then its going backwards.
ill have a look tommorow and see if i can find the terminals to reverse the polarity if needed
thanks
neil

[Declan_Burns]

Neil,
I have my doubts on the trick with the tissue but by all means try. I would think it would still blow out the air -just not as efficient as when the direction of rotation is correct and could be noisier.
Regards
Declan

[timetraveller]

someone elses tip not mine obviously its not gonna suck like a hoover but it worked for someone so its worth a try

[bmcecosse]

I believe you followed the 'tech tips' - which are sadly lacking in many ways...........
Don't bother with the points - if you want to break down a few miles down the road..........
The heater fan will NOT run backwards! And neither does the wiper motor! Both the field and the comm are reversed when polarity is changed - and by dint of Mr Fleming's Left Hand Rule - the motor runs SAME direction! Only a motor with permanent magnet field would run backwards on polarity swap.

[timetraveller]

I believe you followed the 'tech tips' - which are sadly lacking in many ways...........
Don't bother with the points - if you want to break down a few miles down the road..........
The heater fan will NOT run backwards! And neither does the wiper motor! Both the field and the comm are reversed when polarity is changed - and by dint of Mr Fleming's Left Hand Rule - the motor runs SAME direction! Only a motor with permanent magnet field would run backwards on polarity swap.

around five posts ago bmccosse posted that i MUST clean,dress and reset the fuel and dizzy points...........now dont bother???
declan burns says the polarity on the heater needs reversing so the fan runs the correct way
bmcecosse says that it doesnt

im losing the will to live:o

neil

[Declan_Burns]

BMC is right-I have just bench tested the heater and it rotates anticlockwise no matter what the polarity. In other words it turns in the opposite direction to the arrow!
Sorry my mistake.

[MColes]

I'm sure I read somewhere that the earlier round heaters rotated the opposite way when the polarity was changed, so unless I'm also mistaken you were partly right

[PSL184]

BMC was being a little sarcastic - He says "Don't bother cleaning them if you want to break down" The problem with the points in both the fuel pump and distributer is that they work a pip and a dip onto the cotact faces and when you reverse the polarity the pip and dip will try to form on the oppposite faces to before so problems can occurr unless they are dressed back flat or replaced.

[timetraveller]

BMC was being a little sarcastic - He says "Don't bother cleaning them if you want to break down" The problem with the points in both the fuel pump and distributer is that they work a pip and a dip onto the cotact faces and when you reverse the polarity the pip and dip will try to form on the oppposite faces to before so problems can occurr unless they are dressed back flat or replaced.

now thats understandable.....thanks for that
i know bmc is in scotland and its all good and well being knowledgable about minors
but im pretty sure they still speak english up there
thanks
neil

[MarkyB]

This is a forum, on the internet.
What you read here, as elsewhere, is peoples opinions. What they are based on is anyone's guess, it may be experience, received wisdom or religious belief.

Nobody here, or elsewhere, knows everything, including me.

If you treat everything as an hypothesis you shouldn't go far wrong.

[timetraveller]

beautifully put

thanks
neil

ps.post closed as fuel pump sorted and horn working again

[bmcecosse]

Unfortunately - you don't seem to understand it Neil.........

[mike.perry]

Information on this website is given in good faith and whilst every effort is made to check its accuracy no liability can be accepted for loss or damage from use or misuse of aforementioned information.

Circular (fug stirrer) heaters still turn in the same direction when changing the polarity but the rheostat switch is less prone to corrosion on neg earth. Something to do with electrolitic action.

[bmcecosse]

" i know bmc is in scotland and its all good and well being knowledgable about minors
but im pretty sure they still speak english up there "

I try not to get 'personal' on the Forum Neil . Hopefully you can do the same ? You may have some grudge/dislike of Scotland or Scottish people - please keep it to yourself.
Thanks Roy