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Discussion Starter #1 (Edited)
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.

 

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Very nice, I had to do something similar on the beast because the wiring was messed up on the original motor.
 

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How did you determine 20 amp fuse was the correct amperage and 14 gauge was the correct wire gauge?
Links to where you sourced the "silicone" wire , fuse holders, relay and switch would be nice.
Summit racing has a big assortment of the plastic wire loom in many different colors.
 

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Discussion Starter #4 (Edited)
My glow plugs draw between 12 & 15 amps each, so 25% over is 18.75A, fuses available 15 or 20A so 20amps it is.

Wire was from a place I frequent Monday to Friday 0800 to 1600 but googlefoo wil find it on ebay good to 250degC. Not cheap $2.50 per foot Canadian, comes minimum 100Ft. roll. ABYC marine standards 18awg is just sufficient which appears to be the factory gauge used, 16awg is good for 25A in engine bay and my overkill engineering dictates 14awg good for 36A. link to it its actually PTFE (Teflon)
https://www.acklandsgrainger.com/AGIPortalWeb/WebSource/ProductDisplay/globalProductDetailDisplay.do?item_code=WWG3GRL3

Fuse holder from Princess Auto in Canada
http://www.princessauto.com/en/detail/100-30a-led-mini-blade-fuse-block/A-p8479487e

Contactor picked up surplus at Princess Auto but this is it
120-901 - WHITE RODGERS - CONTACTOR, SPST-NO, 12VDC, 100A, BRACKET | Newark element14

Switch is any momentary push button as it just drives the contactor coil so current rating is not a factor.
 

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:clap:Thanks for the links and how you came up with sizes.:thumb:
I just keep wondering:think: why GM thought each glow plug and each bank needed circuit protection with expensive fuseable wire and not cheap simple fuses. :confuzeld. Even harder to figure out,:wtf: is why they ran fuseable wire in the same harness with other wiring. If the fuseable wire does melt, it melts the other wires in the harness:mad::banghead:. My 95 2500LD had that happen.
I'm thinking of making my own harness, also, and was thinking of using MIDI style slow blow fuses. I plan to see if I can find the spec of amperage draw for the glow plugs.
My thought is to retain the OE glow controller with a manual override. In very cold temps the after glow is needed to keep it running.
 
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Discussion Starter #6 (Edited)
Glow plugs being a wire would electrical heating element should be 0.8 to 1.2 ohms when cold but self limiting will go up as they get hotter. 1ohm at battery voltage (12.6Vdc) is 12.6amps, 0.9ohms is 14amps, so 12 to 15amps is normal. I use a clamp on DC current meter to check draw on glow plugs and the math reflects the measured values.
 

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In an effort to avoid the dreaded




I am re-posting original images by uploading them to dieselplace so as to not disappear in the stratosphere. Promoting the content of the topic to remain complete and worthwhile to future readers. :thumb:

Carry on...
 

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GM used fusible link wire for the glow plugs due to it's higher heat properties.
They are not used as "fuses", fuses are to protect a wiring circuit, they don't do much good at the end of the circuit.
 
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