Thanks for the help.
2 wiring questions.
- Thread starter oino
- Start date
Thanks for the help.
Wild Mango
Member
Ole Willem Ohm made it easy for us to work out load currents in a DC system. Take a 60w headlight, current is 60/12 = 5A (power in watts over volts = amps). 20w tail light, 20/12 = 1.7A. Running lights load = 5+5+1.7+1.7 = 13.4A.
Keep in mind the hold in current on a miniature relay coil like automotive ones is milliamps, it takes quite a bit more to get them to pull in (or close). A classic example as Potvinguy says, is the starter motor solenoid which carries 100's of amps, and not only has to pull in the armature but also engage the pinion gear in a lot of cases. If you sized the cable for the hold in current, (milliamps) the thing would never work because the wire would never carry the pull in current (30-40A). That's why an interposing relay works in this case.
Keep in mind the hold in current on a miniature relay coil like automotive ones is milliamps, it takes quite a bit more to get them to pull in (or close). A classic example as Potvinguy says, is the starter motor solenoid which carries 100's of amps, and not only has to pull in the armature but also engage the pinion gear in a lot of cases. If you sized the cable for the hold in current, (milliamps) the thing would never work because the wire would never carry the pull in current (30-40A). That's why an interposing relay works in this case.
The other side of the light connects to switched power. This is the signal to the alt to turn itself on. The light will be on until the engine starts and then it will go out.
Screaming Metal
Active Member
LEDS in the switches are like Hippo's in makeup to me. If I need a LED to tell me a circuit is active I always put it above or below the switch in the board. I've yet to seen a LED in the switch to last even close to the end of the switch. EXCEPT for Nissan and Toyotas switches on their cars even some American cars where the switches are real heavy duty.
If you get the LED switches from Painless or the ExtraHeavyDuty ones, they'll live a long time.
Don't expect a LED switch from Walmart or AutoZone thats $2.99 for 30 Amps to live more than a year even under the most protected circumstances....Cheap and good quality don't go in the same sentence when dealing with electrical components....ususally.
If you get the LED switches from Painless or the ExtraHeavyDuty ones, they'll live a long time.
Don't expect a LED switch from Walmart or AutoZone thats $2.99 for 30 Amps to live more than a year even under the most protected circumstances....Cheap and good quality don't go in the same sentence when dealing with electrical components....ususally.
Screaming Metal
Active Member
Your sooo bad.... hahaha.....
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