Anyone know hw to figure out Amperage?, Im re-wiring my 914 and using upgraded Options

[Dr. Roger]

Im switching to upgraded switches, wiring, and fuses/fuse box.

The first thing i'm running up against is knowing how many Amps is drawn for the headlamps low/high circuits.

I'd like to keep the left and rights, low/high beams seperatly fused and one master switch like the stock configuration.

In addition, also seperating out the switched circuits in the main headlight switch. (running lamps, accessories, and ignition) and fusing them seperatly.

Estimated Amperage draw for
headlights is:
running light:
ignition:
accessories:
starter circuit:

You guys are always top on my list.
(im trying to counter act the negativity of yesterdays BS) (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Best regards,
Roger

[Flat VW]

QUOTE (rogergrubb @ Sep 21 2005, 12:37 PM)

Im switching to upgraded switches, wiring, and fuses. The first thing i'm running up against is knowing how many Amps is drawn for the headlamps low/high circuits. I'd like to keep the left and rights, low/highs seperatly fused and one master switch like the stock configuration. In addition, also seperating out the switched circuits in the main headlight switch.  (running lamps, accessories, and ignition)  and fusing them. Estimated Amperage draw for headlights is: running light: ignition: accessories: starter circuit:

I would use the "fuse ratings" for the various circuits as a guideline.

John

[lapuwali]

Amps = Watts/Voltage. When doing this, use 12v as the system voltage. When calculating wattage from amps x volts, use 14v. Real system voltage is 13-14v while the car is running, and some safety margin is called for. A typical headlight is 55/60W (low and high beams), so 4.6 to 5 amps per light, or 10 amps for both high beams on at once.

This obviously depends on which bulbs you're actually running. Some brake light bulbs are 35W each, some are only 20W. You'll need to tote up the current based on the bulbs you end up with. LED "bulbs", btw, only draw 0.1amp or thereabouts.

When deciding on wire gauges, there are a huge number of "standards" used. The most conservative standard would have you using 10g wire for nearly everything, which is pretty silly. There are some online charts that give you some idea of what gauge you should run for what current, but that's only a rough guidline. Length and how much current you'll actually draw make a difference.

Here's an example table: Amps v. Wire Gauge

Longer runs of wire require a thicker gauge of wire to keep the voltage drop across that wire to a safe level. As the current rises, the wire also needs to get thicker. So, long runs of high current wire need to be quite thick (say, rear-mounted battery to headlights). Roughly 10g is used here OEM, and other than the battery to the starter wire (very high current, like 60 amps), this is the thickest wire you'll use. Use 3 or 4g wire for the battery to starter. Use 10g for the front lights, use 14 gauge for other "power" uses (ignition to starter), and use 18g for everything else.

The coil uses about 3 amps, tops. Fuel pumps run 3-4 amps. Blower motors 4-5 amps.

[Dr. Roger]

thank you so much james,

that's exactly what i needed to know.

i'm sorta getting stoked about ironing out these problems. once these last items are repaired and upgraded i wil be albe to drive with a little more confidence. yes, just a little more..... LOL =-)

to do list:
1. wiring upgraded
2. finish fiberglassing front air ducting
3. get right rad caps to hold correct pressures in cooling system and purge system or air.
4. drive her like she's meant to be driven. (IMG:http://www.914world.com/bbs2/html/emoticons/driving-girl.gif)