Coil voltage

[Guppy916]

Hi guys I have just noticed that I have 14.5 volts at my Positive Terminal on the coil, could this be why I keep burning out coils, it's on a 1973 GT6 Mk3 Non Ballasted system

[Howard]

With the engine running I presume?

[glang]

Sounds reasonable as a running voltage doesnt it👍

[glang]

Oh and of course it should stay about that at all revs....

[Guppy916]

Howard yes thats with the engine running on tick over

with the volts ranging 13.5 to 15.25 ish

[glang]

Hmmm thought it would be a bit more stable than that with an alternator... Need to see what it gets to at higher revs but with high system volts I always thought bulbs go first...

[Guppy916]

yes running a Rimmers alternator (17 ACR) 36 Amp part No GXE8211

all bulbs are Led's 

[glang]

Perhaps feel temperature of coil after next good run? Should be warm but not glowing😲

[Guppy916]

Glang, after a 3-4 mile run around town, the volts have settled down around 13.8 - 14.5 from 800 to 3000 rpm, the coil is quite hot but you can hold onto it

[glang]

Sounds reasonable so maybe youve just had bad luck? Im still on an original coil now 50+ years old🤞

[Guppy916]

I hope so, my first coil after the rebuild only lasted 50 miles the second one about 75 miles then with alot of sorting I found that the company i used for my new loom sent a Ballasted loom, so i ran a new wire from the fuse box (the white one) so i now have 12volts at the coil, they were both so hot I almost lost skin when changing them. perhaps i'm just being paranoid now

Edited June 13, 2023 by Guppy916