The coil is the original from 1980 and has close to 85,000 miles on it. Never had a problem with it but am planning a long trip and didn't want to have to hunt around for parts if I broke down. The old, working parts, are kept in the trunk just in case.
Last edited by WYSpider on Thu Sep 08, 2011 11:50 am, edited 1 time in total.
coils do get extremely hot, there has to be some result of creating 10,000-20,000 volts hundreds of times per minute. Oil filled coils should be mounted at an angle, the hottest point is the - post. If it's upright, that post is not covered with oil and will overheat
Coils will pass current constantly as long as the (-) side of coil grounded.
Four amps sounds about right. And you will have 4 amps going in the pos and 4 amps coming out the neg.
Checked my old 64 Chev PU after a half-hour truckin around. Old 6cylinder, coil, probably original, mounted straight up in original bracket mounted to block.
Hottest point...bottom of coil, 180 deg
Neg term 148
Pos term 133
Engine block, 188
Head, 200.
Its a hot day, hot for Libby anyway.
This is with a non-contact thermometer.
Taking my fiat into town this eve, will check it's coil too.
Call me crazy but do you have it wired backwards? I know it is unlikely, but???
Coils are just transformers. Wired correctly they step voltage up, wired backwards they step it down. The WILL operate backwards but very quickly overheat and fail. I learned this the hard way on my 1970 XKE. Car would start and run for a while then quit. Drove me crazy until an old guy I knew told me about when he was a teenager and he and a girl picked up her dad's brand new Rolls in NYC to drive it to CT. Got just outside the city when it died. Coil was wired backwards at the factory! Swapped the + and - leads and went on their way. Same thing on my Jag.
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
The coil on my fiat was wired backwards for YEARS and never gave me any trouble. I hooked it up to my scope a month ago and saw it. Switched wires around, still runs good. IN the good ole days when most cars had external coils, we would see the occasional coil hooked up backwards. Running cars. And we just corrected the wiring. I'm not sure just why coils are designed to have polarity only one way, must be a good reason, but I don't know it. They seem to run either way.
Keith
When I first got my Fiat I went through a couple coils and wound up making a shield from a piece of thin aluminum sheet to keep away the excess heat it was getting from the headers and it seemed to work as I never had another coil burn up.
Hooking up a coil backwards will not make it step down, it will only reverse the electrical path of the spark at the spark plug and it does make a difference.
