Discussion Forum - Northstar Chevelle Club

Lost in the 60s · President

Electric fan draw

67ss · 1K+ Club

Fans can typically draw 20-30 amps each. The A/C clutch is about 5 amps. So with two fans and the a/c clutch that is a pretty good load.

Lost in the 60s · President

67ss wrote:
Fans can typically draw 20-30 amps each. The A/C clutch is about 5 amps. So with two fans and the a/c clutch that is a pretty good load.

It is a single fan with 2 speeds, so you're saying having the 2 wires together now for high speed, each speed is going to draw 30 amps for a total of 60 ? I have it on a 70 amp relay, so that should be OK.

Bobs_Place · Vice President

I wouldn't think the alt could load the engine that much at idle, alternator typically don't put out as much at low speed. Do you have a very small pulley on the alt?

If the fan was wired for two speed I "think" the low speed would come on as needed and stay on when the high cam on. Don't know for sure.

Can you check the amperage draw on each wire?

Lost in the 60s · President

Pulley appears to be a standard size.

I don't have the fan wired for both speeds, ONLY high, as I figure if it needs the fan, crank it up. The controller powers the low speed circuit first, so the fan is wired to that terminal only, per Dakota's controller instructions. When I initially wired the circuit, I connected the "high" speed wire on the fan to the relay and left the low speed wire loose. What I discovered this week was, the fan runs the SAME speed on either low or high wire alone, but together, it runs on high. My thinking is, if the fan was wired and relayed for 2 speeds, the controller would power both relays for high and end up the same as having the 2 wires together in 1 terminal. It just baffles me that it loads the engine this much to run a fan. With the A/C on yesterday, I had the engine die twice, just letting off the throttle for a stop sign...

No, I can't amp check the individual wires, but I should check the feed wire for amperage to make certain it isn't drawing too much. I did drive the car for 140 miles yesterday, without anything catching fire or exploding, so it isn't too critical.

SShink · 3K+ Club

Does the engine loading vary only when the AC compressor is running, or always loaded down only when the fans are running?

I had to add a kick up solenoid for my AC due to the engine loading and the lumpy cam in the 383.

67ss · 1K+ Club

Oh if it just a single fan then no it should only draw 20-30 amps, not 40-60. I thought it was two fans.

Bobs_Place · Vice President

Is it possible that with the fan on high, a/c clutch on and blower motor on, the voltage at the ignition system is to low? Are you using a one wire alternator?

Lost in the 60s · President

I called CC and confirmed that I need both wires to get the fan to run on high...seems bass ackwards to me, but what do I know...

The only thing the tech wanted me to do, was run the ground directly back to the battery. I told I could get it the block, where the negative battery cable is attached, but 6-7 ft of wire back to the battery wasn't going to be any better than where it was on the fender.

So I made that change.

The fan doesn't run after I shut the car off either and it is supposed to. The ground for the controller may not have been good, so I changed that too. It does have power with the key off.

Then I mounted the TCC controller where I can see the engaged light to know when the converter is locked and then I'm going back out for a ride. It doesn't seem to drop out after slowing below the set point, so I need to have a visual on that function. B&M says it should. If it doesn't, I also have to find a 4 terminal brake switch to disengage the converter when braking. If the converter drops out below set point, I shouldn't need it to cut out with the brake switch...anyone else feel like they're on a merry go round ???

Chris with the converter NOT locked on the freeway at 70, the trans temp does climb to 150. With the converter locked, the temp drops to around 120...70 mph is 2100 rpm, I hope that is enough for pulling the trailer without lugging the engine. 3rd gear lock up is way too low to run much over 62 mph...the rpm is about 2600. I will use it in wind and hills, but hoping to leave it in OD/lock most of the time.

SShink · 3K+ Club

Mitch, I had to find a 4 terminal brake light switch to make my B&M torque converter controller work properly. I think I used one from a mid-80's G body that had cruise control. Chris P. may have helped me with the part number.

Lost in the 60s · President

Actually, the controller does drop out once I slow down, so that part is working good.
Then the cruise control quit, which feeds from the TCC generator. I pulled over and the fitting between the 2 was loose so I tightened it by hand and then the TCC wouldn't work either !!!!!!! I'm SO tired of this **** with this car. Everything I do to try to make it better just turns into a friggen nightmare.

Lost in the 60s · President

Well, 1 thing I set out to do this morning is a success. The huge fan draw WAS a poor ground. I ran a #10 wire to the block and when the fan comes on now, it draws the engine down a little for a second, until the fan gets up to speed, and then the engine idles like normal. NEVER thought that was going to fix this...

The loss of TCC and cruise was a square drive key that was/is too big to fit between the 2 pulse generators. When I tightened them by hand, it bound up and barely turned. I ground it down to fit better and allow the generators to turn easily, but will order a couple from Speedway and replace this one next week. I have no idea how I dodged a bullet of having any of the plastic parts in those generators, or the driven gear strip out. Guess it was my lucky day after all.

I called Dakota about the fan not running after key off and it turns out I have the power lead on the relay on an ignition circuit, instead of full time. I'll fix that another day. 8 hours of, mostly, frustration is enough for 1 day.