Relays Headlights, Electric Fan. Is it too much??

[67chevemall]

I would love to do the headlight upgrade, but I also am putting the electric fans in this week.

Is this overkill on the electrical (ALT.)or can it handle it!


Any tips or ideas?

I'm using this as a guide!

http://www.madelectrical.com/electri...adlights.shtml

Cheers

[Mudder]

A 100 amp alternator or a 140 amp would be nice. Good thread over at myoldtruck.com on this same issue.

[67chevemall]

Nice truck Mud man!WOW!

I check that thread!

[68LSS1]

What brand electric fan? I think you'll be ok but if it was me I'd upgrade the alternator too. Those guys over at MAD Enterprises have some good info. I'll be using their stuff when the battery goes in the bed with their cut off switch.

[BobbyK]

I had an GM 80amp before my e-fans were installed.

But after I installed them the 80amp couldn't keep up.

I put in a 140 amp 1 wire alt that worked fine but then I read MAD's article comparing the 1 wire to the orig. 3 wire setup.

I since converted that 140 alt to a 3 wire,remote sensing alt.Hasn't let me down since.

[67chevemall]

Nice Blazer! Cool pics!

What do you mean by couldn't keep up! Did everything dim and die when u put them on? I don't really want to replace my Alt cause it is 2 weeks old!DOE!

I could put it on the 78!

[BobbyK]

I have a Hellroaring battery isolater with a remote moduale
http://www.hellroaring.com/remote.htm

The remote module mounts incab and will let you know (via an LED)when the alt is putting out enough juice to keep up with the electrical demand and able to charge the batteries at the same time.

Well after the e-fans went in the LED would go out at idle conditions(not enough output at idle)So considering the alt was old,I upgraded.

[67chevemall]

Cool unit!
I think I'll try one big fan and see what happens!

Anyone else with a stock set up and electric fan??

[Mudder]

Believe mine is a perma cool from Jegs and it draws like over 2800 whatever. I'm not running any kind of stock fan or shroud. During the summer months the hottest it has gotten is about 205 and thats running it hard and over 100 degrees outside. I am running a 100 amp and thinking about going to a 140. Stereo sucks a lot of juice and with the lights at idle they dim a little.

[fatfords]

67chevemall,
If the alternator won't keep up at idle with all the new stuff, you might try a smaller pulley on the alternator. I know they make larger pulleys, I would guess that someone makes smaller ones also. Maybe for different applications for the same GM alternator?
Good Luck!

[Mudder]

Very true a smaller pulley may be the ticket and lots cheaper.

[67chevemall]

Good Idea!

What size fans are you guys runninng?
BobbyK has 2- 14"

[Longhorn Man]

One note, installing the relays for the headlights will not draw more current from your charging system, it will simply re-route the power for more efficent use.

[Blue68]

Mad electrical is full of good information. Relays are a good idea regardless. I've swapped my headlights over to relays and they don't dim. Granted, the alternater and setup is out of a '98 truck, and I rewired my entire underhood with relays to the Lockup converter, HEI and choke as well as the lights. Now my ignition switch isn't doing near as much. I'm even running the stock amp meter with the newer alternator which is suposedly around 115 amps. Just got to make sure you wire it like the original was and get the wire guages right.

For your question, if you go straight to the power source (the distribution point after the alternator) for the main relay feed, and only switch the fan with a heat sensor or ignition you will be good on that front. The ultimate answer will depend on your alternators rating and the cumulative value of fan's amperage, plus headlight (halogen) amps, HEI vs. points amps, and other electrical components you are running as to whether it's too much. May have to do some math. Or just upgrade.

[67chevemall]

"if you go straight to the power source (the distribution point after the alternator) for the main relay feed,"

So don't run the feed of the Battery, use the ^!

I have a wire running from the battery over to the voltage regulator
And horn, then into the cab!
I was going to run the relays off this or re- run another wire!
But I will look for the distribution point after the alternator tonight!

Thanks

[Blue68]

I should be more specific perhaps. If you take a look at this diagram http://www.geocities.com/chevroletc1070/v8engcomp.html you will see a point just above the horn where the alternator 12R, Voltage Regulator 12R, battery 12R, ammeter 18B/W and main power into the bulk head 12R all meet. This is the juction I'm referring to. It is on the driver side behind the headlamp. It gets you pretty much the same benefit but puts the draw closer to the alternater and not at the end where the battery is drawing to be charged If yo uconnect at the juction box, you also increase the draw accross the ammeter, granted by ever so little. Think of it as a circle made of two pipes, one big 12R and one rather small 18B/W. If you place more draw there, then both pipes will see an increase in flow.

[67chevemall]

Thanks I looked at it on the weekend! I think I'm going to put 4 relays under
the volt. Reg. on a piece of metal!

[BobbyK]

Here's how I wired up my relays.

[67chevemall]

SWEET! Driving lights too!

[67chevemall]

Anybody run their Ign. at the Distributer of a relay?

[BobbyK]

Never thought of it but it could easily be done.

[Blue68]

67chevemall,
I sure do. I have a very similar setup to BobbyK's under my hood with the relays for the headlights and the distribution block. The one difference I don't notice is I'm running fusible links off my block, on the driver's side. Under the dash, I have one or two more relays (can't remember right now, been a while) which power the electric choke, HEI distributor, electric fuel pump, and torque converter lockup. All of these items are on all/or most of the time. And with the ignition, it does much better with a good solid power supply. I ran a 10 guage wire from the aforementioned distribution block through an unused 'port' in the bulkhead into the cab to another distribution block that feeds a 4 fuse box to power these particular items.

[BobbyK]

I run a fusable link from the alt to my main distribution block,another protecting the feed into the fuse box.

The blue wires feeding the headlight relays are fusable links as well.

Power to the e-fan relays are protected with circiut breakers.

The drivinglights relay has a 15amp fuse built in so no fusable link on that one.

Fusable link going to fuel pump relay.

That's all I can think of at the moment.

[Alex Hayley]

BobbyK, can you tell me what relays and plugs to the relays you used for your headlights? Also, where did you get that power distribution block?

THanks,
Alex

[67chevemall]

I have one of those dist. blocks on my 78 firewall!
So it is probally off later model trucks