I need to pick some brains. I’m doing a restomod and adding two cooling fans and an electric fuel pump. All three require 30 amp each for a total of 90 amp. I want extra capacity so I am looking for a total of 120 amp so I am looking for a combination relay and fuse holder that I can feed with one cable from the battery. I have found these combo units online but the four slot units only have two 30 amp fuses and the total capacity is less than 120 amp and the feed wire is too small. Please give me some ideas. Thanks in advance for the replies and Merry Christmas.
30 amps for a fuel pump? wow....I'm feeding a 700 hp engine with a 5 amp fuel pump. Maybe you ought to stick to traditional builds, we can help you out with how to cool an engine with a mechanical fan, no electricity needed.
Jeez squirrel ya beat me too it. That is a m***ive amp draw for a pump, might want to look again at that. I would avoid shopping on Amazon for anything like what you are looking for unless it's common to mount big fire extinguishers in whatever a restomod is.
You both have me thinking. I will check the fuel pump draw on the spec sheet. I posted this from memory. I am positive on the 30 amp per cooling fan. Thanks.
I'd double check the info you have. Lots of electric fuel pumps available that don't draw 30 amps and have more thn enough flow.........should be under 10 amps. I also think the 30 amp rating is for both fans rather than each fan, but if not there are lots of other dual fan set ups that draw only about 30 amps. Its a car that is basically stock/restored to look similar to stock.........that some one has added some non-stock things to............like a bigger engine and custom wheels...........same thing we did in the fifties only we didn't have to restore them........just a new trendy word to say the same thing differently.
I'm familiar with the term restomod, it lives in the same place as the term ratrod. I guess I was just taking a bit of a jab at it. Hey, it is the H.A.M.B after all.
I'd bet a large number of car owners on the HAMB have things on their cars that aren't HAMB friendly. We just don't talk about them. Don't ask, don't tell.
I figured that's what you were doing, actually I meant what I said to be a jab at the term "restomod", sorry if it didn't come off that way. I don't care for the continued use of labels to differentiate what we are doing. I prefer simplicity that unites us more. We may not all have the same tastes in cars (thankfully), but we all have an interest in modifying cars and trucks whatever we call them.
One more resource to check would be the makers of the accessories. If they are a quality maker who cares about continued sales and customer feedback rather than a drop shipper with a bunch of counterfeit offshore junk listed for sale, they should have a tech department or at least a power supply kit or recommended parts.
Pick a wiring supplier and go from there. Someone like Painless has everything you'll need. For example, three of these and you're golden. Don't over think it.
In spite of the above posts about the aftermarket harnesses, there are ways to do this, just not with their methods. Wiring 101 | The H.A.M.B. (jalopyjournal.com) Buss makes fuse panels with ratings of up to 120 amps each. None of the aftermarket suppliers use these.
Lots of Waytech’s stuff isn’t HAMB friendly, but there’s the kind of stuff you’re looking for. https://www.waytekwire.com/?gad_sou...MImenPk5umgwMVAjetBh2TTgE3EAAYASAAEgJBvvD_BwE
Something I found the other day when starting a 90 Corvette parts car, is that the alternator is more compact than the full size car/truck ones. To get a small Powermaster is quite a bit more expensive...maybe 3-4 times than what a new Corvette/Delco runs at Rock Auto. Bout $75 if I recall and no core needed. It has a 110 Amp rating and a Chevy connector plug already. To be fair, the Powermaster puts out quite a bit more Ampherage than the Corvette, but 110 is plenty for most people. Also, the OP should know that one wire alternators often don't have much output when idling in traffic ...when you need the fans. Anyway, for general info, the Corvette is more compact and has a decent output as well as reasonably cheap. Probably won't find them immediately available at an Autozone if you break down, maybe take a day to get.
Check out leash electronics. He sells a 4 or 8 relay board. Each relay is rated at 70 amps. You add appropriate rated fuses to it. For example, one of the fans that runs at 30 amps. You would put in one 30 amp fuse (or two 15 amp) in the circuit for the relay. He can also set it up for positive or negative triggers. If you have more questions, feel free to pm me.
Before going too far, be sure the fans will big enough to actually cool the engine. Hate to see you go to a bunch of work and expense for a ****py setup. Post a picture of the fan and shroud.
My biggest question is can the ignition switch handle turning on all these accessories? I have a ot car I am working on that will have aftermarket ac/heater, 30 amp fuse each, fan 30 amps, and a fuel pump 7.5 amps. Was thinking just putting it all on the acc terminal on the back of the switch. But got to thinking about it, don't know if the switch can handle all the extras plus the rest of the car?
Get yourself a Davies Craig controller. It is a digital readout fully adjustable electronic fan control with two replaceable relays and a 10-second time delay between fan on initiation. Each fan output signal is fused. Made in Great Britain. https://www.summitracing.com/parts/dcw-dc-0444 And if you go with the electric fuel pump wire it through an oil pressure safety switch, "just in case".
I use my sons clamp on electronic Ampmeter to start before doing anything. Before I ever started I knew exactly what full load was with nothing on up to when everything was on including high fan, high beams, and brake lights which is missed by most. I found out why my 56 came withand only needed a 30 amp generator. For the most part I will do anything to stay away from electrical devices that can have mechanical ones. Fans, pumps, etc. Surprising to me that my car did not need heavier wiring when AC was added especially the way I use it.
Let me go OT a bit. My ‘89 IROC, now my daughters, has two fans. With both fans on and the AC on and idling, the voltage gauge (after dropping off) would come back to the normal 13.x volts. I don’t think the alternator is more than 80 amps? but would have to check to verify. But one major difference between it and HAMB cars, it maintains the same 650rpm or so idle speed.
In a word, no. Ignition switches are rarely rated for more than 30 amps (with de-rating for better contact life, 24 amps), it's really easy to exceed that with a bunch of added electrical. Better bet is to use a 100 amp (or larger if needed) continuous-duty relay to switch that half of the fuse panel and control it off the ACC contact on the switch. McMaster-Carr sells the relays, as well as most industrial electrical supply houses. Read the thread in post 12 for a fuller explanation.
Crazy Steve, that is what I thought the ignition can't handle the load. There are relays in the wiring harness for the heater and ac as well as the fan. They all say to hook to a 12 volt source. I like the idea of a large relay and will look into it.
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