Discussion
Hi clever people. I would like to make my own hot start kit. Can anyone describe what the relay is doing. I seems to be just bridging a wire that has to be cut from the pictures I saw at www.chimaerapages.com/resources_hotstart.php
Regards, Robin
Regards, Robin
Hi Robin,
The hot start kit is a little more than just one wire, I bought mine a couple of weeks ago from Modwise, a few wires, soldered connections and what looks like a relay, complete with an led test lamp for £20.00 incl p+p. It is an absolute bargain, easy to fit and has cured the problem.
HIGHLY RECOMMENDED !!!!!
The hot start kit is a little more than just one wire, I bought mine a couple of weeks ago from Modwise, a few wires, soldered connections and what looks like a relay, complete with an led test lamp for £20.00 incl p+p. It is an absolute bargain, easy to fit and has cured the problem.
HIGHLY RECOMMENDED !!!!!
Yep,
can confirm, the piece of kit is spot on, David Beer, the owner of Mod-Wise is a top man for technical knowledge and help - thoroughly recommended! It's not really worth making your own kit up.... unless you have really got nothing to do. Go to www.mod-wise.co.uk
can confirm, the piece of kit is spot on, David Beer, the owner of Mod-Wise is a top man for technical knowledge and help - thoroughly recommended! It's not really worth making your own kit up.... unless you have really got nothing to do. Go to www.mod-wise.co.uk
TVRobin said:
Can anyone describe what the relay is doing?
It's allowing a very small current in one circuit to control a much larger one in another circuit.
TVRobin said:
I have a degree in electronics and I just NEED to know how it works!
The relay contains a coil made up of thousands of turns of fine copper wire insulated by a thin coat of shellac. The whole coil is wound around a soft iron former. When a voltage is applied to the coil, a current flows through it. This induces a magnetic flux in the soft iron former. At one end of the former is mounted a soft iron plate, hinged at one end and spring loaded to keep it away from the former. Joined to (and insulated from) this is one or more electrical contacts. The magnetic flux created in the former attracts the soft iron plate. This attraction is greater than the force applied by the spring, so the plate moves towards and strikes the former. This is the characteristic 'click' you hear the relay make. This action will either open or close (or both) one or more sets of contacts in the relay. When the current to the coil is switched off, the magnetic flux ceases and the spring is able to return the plate (and therefore the contacts) to its normal position.
Cider Andy said:
TVRobin said:
Can anyone describe what the relay is doing?
It's allowing a very small current in one circuit to control a much larger one in another circuit.
TVRobin said:
I have a degree in electronics and I just NEED to know how it works!
The relay contains a coil made up of thousands of turns of fine copper wire insulated by a thin coat of shellac..........
Thank you Andy, I seem to remember that from my 1st year. I think too many gin & tonics has reduced my ability to ask the right question. What I wanted to know was; how can I use one, which wires on the car is it helping?
Regards, Robin.
Surely if you have a degree in electronics you can deduce what's going on in the wire that prevents it from working properly when hot and therefore what the relay is doing! 
The hot start kit, IIRC uses the initial wire from the battery (via the ignition switch) to the starter motor as a trigger for the relay. A new, larger diameter wire is used from the battery to the starter motor and is less susceptible to heating and increased resistance.
The problem stems from the fact that the original wire to the starter motor was quite a small diameter and prone to overheating (due to the dirty great big engine that sits quite near it!). As it heated the resistance went up, eventually to such an extent that not enough current travels along the wire so the starter motor cannot work. This is one of the reasons why sitting waiting for it to cool down sometimes sorts the problem (albeit temporarily).
The hot start kit uses the original wire to trigger a relay. Therefore the amount of current required is significantly less and heating with subsequent drop in current is no longer an issue. You need to fit a new, chunky, wire from the battery to the starter motor via the relay. This new wire will be the one that carries the large current to turn over the starter motor.
Hope this helps
The hot start kit, IIRC uses the initial wire from the battery (via the ignition switch) to the starter motor as a trigger for the relay. A new, larger diameter wire is used from the battery to the starter motor and is less susceptible to heating and increased resistance.
The problem stems from the fact that the original wire to the starter motor was quite a small diameter and prone to overheating (due to the dirty great big engine that sits quite near it!). As it heated the resistance went up, eventually to such an extent that not enough current travels along the wire so the starter motor cannot work. This is one of the reasons why sitting waiting for it to cool down sometimes sorts the problem (albeit temporarily).
The hot start kit uses the original wire to trigger a relay. Therefore the amount of current required is significantly less and heating with subsequent drop in current is no longer an issue. You need to fit a new, chunky, wire from the battery to the starter motor via the relay. This new wire will be the one that carries the large current to turn over the starter motor.
Hope this helps
SiH said:
Surely if you have a degree in electronics you can deduce what's going on in the wire that prevents it from working properly when hot and therefore what the relay is doing!
The hot start kit, IIRC uses the initial wire from the battery (via the ignition switch) to the starter motor as a trigger for the relay. A new, larger diameter wire is used from the battery to the starter motor and is less susceptible to heating and increased resistance.
The problem stems from the fact that the original wire to the starter motor was quite a small diameter and prone to overheating (due to the dirty great big engine that sits quite near it!). As it heated the resistance went up, eventually to such an extent that not enough current travels along the wire so the starter motor cannot work. This is one of the reasons why sitting waiting for it to cool down sometimes sorts the problem (albeit temporarily).
The hot start kit uses the original wire to trigger a relay. Therefore the amount of current required is significantly less and heating with subsequent drop in current is no longer an issue. You need to fit a new, chunky, wire from the battery to the starter motor via the relay. This new wire will be the one that carries the large current to turn over the starter motor.
Hope this helps
The hot start kit, IIRC uses the initial wire from the battery (via the ignition switch) to the starter motor as a trigger for the relay. A new, larger diameter wire is used from the battery to the starter motor and is less susceptible to heating and increased resistance.
The problem stems from the fact that the original wire to the starter motor was quite a small diameter and prone to overheating (due to the dirty great big engine that sits quite near it!). As it heated the resistance went up, eventually to such an extent that not enough current travels along the wire so the starter motor cannot work. This is one of the reasons why sitting waiting for it to cool down sometimes sorts the problem (albeit temporarily).
The hot start kit uses the original wire to trigger a relay. Therefore the amount of current required is significantly less and heating with subsequent drop in current is no longer an issue. You need to fit a new, chunky, wire from the battery to the starter motor via the relay. This new wire will be the one that carries the large current to turn over the starter motor.
Hope this helps
Thank you Simon it is becoming clearer now. So the relay is providing greater current to the starter motor from the inside of the bulkhead to the starter motor. The loss being from the ignition (position 2 (crank)) to the inside of the bulkhead.
Regards, Robin.
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