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View Full Version : What battery fuse do you use?



Jeff33Ford
03-18-2023, 10:51 AM
I would like to install a fuse at the battery just as an extra precaution since battery is in trunk. Thinking this would work.
Fuse (https://www.amazon.com/dp/B07LC3Q4LD/ref=cm_sw_r_apan_glt_i_5YFSBRKVBPCAC3ZBBQZV)

Is 250A a good size for the 33 with a 302 SBF. I searched around on the forum and did not find any specifics. I am sure this has already been ask.
Thanks
Jeff

progmgr1
03-18-2023, 12:41 PM
I think that the fuse size depends on how much load you have in the electrical system, not the engine size. For example, accessories like air conditioning and electrical power steering will draw more current - so you need a bigger fuse. 250 A is probably fine for a basic build. You may want something larger if you have power hungry accessories. I have a 300 A main fuse on my accessory-heavy '33. I also have a supplemental 100 A fuse block for some accessories and a separate 90 A fuse for my audio power amp.

Keith HR #894

Just 1 More
03-18-2023, 02:12 PM
I would like to install a fuse at the battery just as an extra precaution since battery is in trunk. Thinking this would work.
Fuse (https://www.amazon.com/dp/B07LC3Q4LD/ref=cm_sw_r_apan_glt_i_5YFSBRKVBPCAC3ZBBQZV)

Is 250A a good size for the 33 with a 302 SBF. I searched around on the forum and did not find any specifics. I am sure this has already been ask.
Thanks
Jeff

I have that in a duel on my 68 Camaro, one is a 200 amp and the other is a 30 amp. I use the 200 for my starter, then it powers the duel fans which then have 40 amp Maxi fuses for each fan. The 30 for my Holley EFI
181716181717

Alan_C
03-18-2023, 02:23 PM
I would like to install a fuse at the battery just as an extra precaution since battery is in trunk. Thinking this would work.
Fuse (https://www.amazon.com/dp/B07LC3Q4LD/ref=cm_sw_r_apan_glt_i_5YFSBRKVBPCAC3ZBBQZV)

Is 250A a good size for the 33 with a 302 SBF. I searched around on the forum and did not find any specifics. I am sure this has already been ask.
Thanks
Jeff

The 250A mega fuse is the same size as is provided for the Coyote controls pack from Ford Performance. Should work fine.
Like what was done in a previous post, I have a 250A mega fuse to connect to the starter. I have a second run using a 100A mega fuse for the controls pack and the AAW harness. If you are using any kind of EFI, a direct connection to the battery is most likely required.

Jeff33Ford
03-18-2023, 02:48 PM
Thanks guys. I was debating using a dual fuse as well. Might as well since it is no big deal to add now since I do have a separate run for the EFI and MSD. Main thing is it looks like 250A should be plenty for starting. By the way I am using the Powermaster 9162 starter and should not draw any more than stock starter with the gear reduction and not a big compression engine. Everything is fused further down the line. This is just a worst case scenario and not burn the car to the ground protection.

Just 1 More
03-18-2023, 02:54 PM
Thanks guys. I was debating using a dual fuse as well. Might as well since it is no big deal to add now since I do have a separate run for the EFI and MSD. Main thing is it looks like 250A should be plenty for starting. By the way I am using the Powermaster 9162 starter and should not draw any more than stock starter with the gear reduction and not a big compression engine. Everything is fused further down the line. This is just a worst case scenario and not burn the car to the ground protection.

Mine is a 200 amp and cranking a big block 10.2:1 comp, 600Hp and no issues so far. I'm sure you're good with the 250