Hei to unfused ignition, how big a fuse for inline fuse ?
 

At some point one of the two dread previous owners has converted my truck to HEI... I use the word converted a bit loosely as it is a kludge of the 10th order of kludgedom :banghead:

I have picked up all the pieces and parts to wire into the unfused ignition on my fuse block but one thing I haven't seen in the FAQ or by searching was how many amp a fuse is best for the inline fuse I plan to wire to this ?

TIA

Brian

i didnt use any fuse....

Why do you want to install a fuse when GM didn't use one for the ign. primary wire?

Honestly, i've never used one either.

Well to be honest I am a total newbie to all things bow tie and so searched the board and found an excellent FAQ by a 'longhorn man'

the hei faq

In this thread someone asked if they'd need an inline fuse and he said yes, not knowing anything about the subject and being anal retentive I thought yeah that makes sense if the module were to present a dead short a fuse is easier to replace than a bunch of wire with it's insulation melted off :D

I'll just wire some 10 gauge (the wire on the hei looks like 10 or is this overkill) directly to the fuse block and be happy then.

Thanks again,

Brian

lol, yeah, i know it should probably have a fuse, but like I said, i've never done it as of yet.

Every wire on your truck should be fused. If it's an unfused terminal, it's up to you to add the fuse when you utilize the circuit.

Andy, I know you well enough to say you are smarter than that. Surely there's an inline holder laying around somewhere at your work you could liberate for the HEI in your truck.

Yeah...talk about lazy huh?
I actually have a few spade type fese holders right here....I'll grab one and say "that's for the HEI" and forget about it and then end up buying another. :rolleyes:
Procrastination is like masturbation....even though it feels good while doin it, you're just screwing your self. ;)

10 guage is overkill.

Mine is 12 gauge, unfused. :)

I tried using a 30 amp inline fuse on my race car(with HEI) once, and it popped & banged at high RPM (around 5500-6000) for a few laps, then finally blew the fuse. I rewired it without the fuse and it ran great. I'm not sure what you need, maybe a fusible link, or a breaker, but a 30 amp fuse won't do it.

I've been using 12 gauge wire with a 5 amp fuse , powering the Hei and Electric choke , no problem's.
I take the fuse out when I need an ignition shut off ,to deter thief's .

5 amp? Wow, I don't know how you're doing that, Bill. I'm really confused now, :confused: but then again, it doesn't take much, lol. :p

12 gauge wire and 20 amp fuse is sufficent for most street racers.

I haven't used fuses on HEI I have put in. If you use 10 gauge wire it is larger than the fusible link off the battery so it should not melt before the fusible link. But a fuse would make sense as most other large current accs. use a fuse like AC, Blower and all of the lights. the lighter stuff would use fuses because the wire is much lighter than the fusible link and would burn the harness. The internals of the dizzy are only about 18gauge so you know it is not pulling a lot of current. I haven't put a meter on it to see what it draws but I would say it not a lot.

RainFade, check out this link and scroll down to the paragraph "using a inline fuse with your ignition coil". Good info. Fred T was right on the money at recommending the 20 amp fuse. If you don't rev it up too high you can get away with the 1 amp per 1000rpm. formula. Keep a spare module in the glove box anyway.

http://www.centuryperformance.com/mallory/unitest.asp