Resistor purpose and rating

[tlove007]

Anyone know what the ohm reading should be across the pre charge resistor on the solenoid of a 2003 cc ds iq? I would also like to know what purpose it serves and what would happen if it was removed.

Thanks

[TahoeDawgZ71]

It is designed to let minimal power bleed through and keep the capacitors in the controller fully charged at all times. Otherwise, there would be a sudden rush of energy into the controller every time the solenoid clicks, putting the controller at a high risk of getting damaged. Here's a pic of the resistance rating on a brand new one.

[tlove007]

While I'm asking dumb questions...does the small diode serve a meaningful purpose as well? The small diode has broken off but as of yet it has not affected the carts operation.

[TahoeDawgZ71]

A transient-voltage-suppression (TVS) diode is an electronic component used to protect sensitive electronics from voltage spikes induced on connected wires. It's very important to say the least.

[mrgolf]

My 1947 model airplane had a diode on the master solenoid as well. It was there to protect the modern radios from voltage spikes. Not sure if the old tube type radio needed the diode or had it. I'm not sure they had diodes in 1947.

[greg-g]

Originally Posted by mrgolf

My 1947 model airplane had a diode on the master solenoid as well. It was there to protect the modern radios from voltage spikes. Not sure if the old tube type radio needed the diode or had it. I'm not sure they had diodes in 1947.

They did have them and in fact I have some that came off of Navy ships in the early 50s actually their brand-new in the plastic tube I think there something like 1500 Volt 150amps and about the size of your wrist with a braided cable coming off one end
Also one of the old tubes in the really old radios was a rectifier tube

[mrgolf]

Amazing how they have made them as small in size they are now.