Anything and everything Herald. Talk about anything from the first 948s to the last 13/60s.

Alternators, dynamos, lights, wipers, etc.

i have a + earth 12/50 herald. what are the implications of chaging this to - earth and how simple is it to do so? thanks

I like +earth think iits great talking point, keep if you can.

But depends on your reasons for wanting to change it, the most common reason is because they want a alternator instead of a dynamo for better battery charging. if its for a stereo then just take both wires straight from the battery with a fuse and wire it as normal.

if you are changing it for a alternator then it is verry simple to change over and not to hard to do, a little conecting of wires where the regulator is, (black box to right of battery) ,swap coil wires over and thats it. unless extras have been added in its life like spotlights, radio, or something.

I have changed mine over, as i changed to engine with alternator on my 1200.

I don't think "just take two wires from the battery and wire as normal" would be very safe.... at the very least you would have to isolate the stereo chassis from the car ground, including the screen of any aerial connection, or you will get a dead short! If this is the reason for changing over it's much easier and safer just to reverse the battery (may need longer leads / new post connectors) and repolarize the dynamo to charge negative earth. Procedure is fairly simple: turn off everything, reverse the battery connections as required, disconnect the dynamo field connection (smaller terminal), then use a separate piece of wire to connect battery positive to the field terminal briefly (you will see some smallish sparks when you break the connection), reconnect the normal field connection, reverse the connections to the coil. Now start the engine and check that the ignition light goes out normally. If not, repeat the field polarizing exercise....

Apart from the coil, the only other standard item which may be polarity sensitive is the heater blower, but it works almost as well backwards as forwards anyway!

Chris

A friend of mine tried to jump-start my +ive earth Courier van with his -ive earth engine...connected his -ive black jump lead from his neg terminal to pos terminal of my battery, and his +ive red jump lead from his +ive terminal to my car body as this was his thinking as mine was +ive earth, went to start and his car was almost dead, and afterwards both leads got severely hot and smoke was coming from my +ive terminal... sparks nearly welded the lead on to my battery....

er, well as electrics are not my forte i was a tad perplexed so i opted to just re-charge with trickle charger overnight. It started 1st time, however after a run it spluttered to a halt and wouldn't start for ages and ages. Someone said to me that i could have possibly damaged the coil or reversed its polarity....would that be the case??

If so,what do i do to get it back to normal?? would things like the dynamo and heater be messed up as well and if so how would i correct in simple idiot-proof terminology!!!

cheers chaps
Stu

You cannot have reversed the polarity of the coil, nor do I see how you can have damaged it. The most likely damage will be to the battery, and after that the dynamo or control box. If you look at previous posts on converting to -ve earth, you can see how to repolarise the dynamo if needed. If the control box is fried, the only option would be to replace. But if the system seems to be charging the battery ok, then you have probably damaged nothing. Is the ignition warning light working as it normally does?
If your friend's car had an alternator, then he might not be so lucky...........................

cheers Chris - so the symptoms that i described (erratic running, poor starting etc are down to the generator being wrongly polarised?? so i just need to swap the wires around on the back when ign on , and then turn off and then swap the wires back again before starting, right?

i put the ign on, then swapped both generator wires over (nothing happened) and then swapped coil wires over, slight spark, then put them back where they were.
Would this have cured my problem???

cheers

i want to put a stereo in it but i am also looking to fit an immobilser

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