Rebuilt glow plug wiring

[ditchpig]

After a couple of quick fix's replaced glow plug wiring. High temp 14Awg silicone wiring, fuse blocks (20A fuses) mounted to manual glow plug parallel contactor. Ran out of loom but had enough to do where hard to get to.





Passenger side used high temp (2200F) sleaving.

 

[Will L.]

The work looks nice, I hope it holds up for you. Your 14 gauge wire is good for 10' length at that load, which I'm sure your shorter than that so that's cool. If the fuses pop, just get the slow blow ones.

Now to why the factory goes to the expense of fuse able link wiring instead of fuses: Each glow plug after moderate uses will easily pull 2 ohms. At 12 volts that's 12 amps each. Unless you bought slow blow fuses, the regular ones are designed to pop at 10 seconds under full load draw. Depending how long your plugs cycle, and the age of them could lead to some frequent fuse swaps. Then of coarse the expense of 8 separate fuses.

 

[ditchpig]

Question on calculations & formulas. I(amps)=V(voltage)/R(resistance). Most heating elements resistance from what I know are ~1ohm or less therefor 12.6V/1ohm=12.6Amps if it where 2ohms the current draw would be 6.3Amps. Measured my glow plugs all are between 12 & 15 amps.

For 14awg wire the American Wire Gauge very conservative continues rating of 700 mil per circular amp rule of 0.0641" diameter conductor in chassis wiring not in bundle is 32amps when bundled ~ 26amps. Resistance is 2.525ohms per 1000ft., so on my longest run of 6ft. that's 0.01515ohms (negligible). Rule for conductor length in engine bay at full current rating continues use is 10ft. 18awg is good for 16 amps in this use and appears to be what GM used (cost).

Max 15amp draw with 25% over is 18.75amps, fuses readily available 15 or 20amps so 20amps it is.