Electric fan questions

[beermonkey9417]

when i got my new chevy high performance mag theres an ad for mr.amp in there, ill go take a look.

heres the site, but DAMN there expensive! http://www.performancedistributors.com/alternators-mramp.htm

 

[Longroof79]

when i got my new chevy high performance mag theres an ad for mr.amp in there, ill go take a look.

heres the site, but DAMN there expensive! http://www.performancedistributors.com/alternators-mramp.htm

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Thanks bro, I appreciate it. I'll check it out.

 

[FE3X CLONE]

[quote="Longroof79]
BTW, are you using a controller with your fans.. and if you do, is there any particular brand or brands that you recommend?[/quote]

With the LT1 fans I was using a Perma-cool adjustable thermostat/controller as well as one of their 30A relay's for the second fan. Worked really well.
This is the one I was using: http://www.summitracing.com/parts/PRM-18905/
Although mine has a 3/8" NPT water temp sender that I could screw directly into the intake. I generally don't like the "probes", I think the NPT senders work and look better.

With my new Derale setup, I have three relays running them that are activated by my EFI computer. That way I didn't have to use an aftermarket controller. Which was good because I didn't have any more spare water ports after installing my water temp gauge sender and the ECU's coolant temp sensor.

 

[85GPLef41]

when i got my new chevy high performance mag theres an ad for mr.amp in there, ill go take a look.

heres the site, but DAMN there expensive! http://www.performancedistributors.com/alternators-mramp.htm

I bought my 130 AMP Napa gold csi alternator for $20 with a $5 dollar core charge from a pull and save.. i looked for the newest looking one and then took it to get it tested right away..luckily i got one with a recent rebuild one from NAPA and it tested good. iT came off a 94 Caprice and i swapped out the serpentine pulley for a v-belt one plus a csi adapter and it bolted right in. Can't beat that! :wink:

As for the controller how accurate is it?

 

[FE3X CLONE]

As for the controller how accurate is it?

It's as accurate as any other temp gauge.

To set it, I just watched my water temp gauge and when it reached my desired temp that I wanted the fans to turn on (190*F) I turned the knob on the control box until the fans kicked on.

That's all you have to do to set it.

 

[Longroof79]

[quote="Longroof79]
BTW, are you using a controller with your fans.. and if you do, is there any particular brand or brands that you recommend?

With the LT1 fans I was using a Perma-cool adjustable thermostat/controller as well as one of their 30A relay's for the second fan. Worked really well.
This is the one I was using: http://www.summitracing.com/parts/PRM-18905/
Although mine has a 3/8" NPT water temp sender that I could screw directly into the intake. I generally don't like the "probes", I think the NPT senders work and look better.

With my new Derale setup, I have three relays running them that are activated by my EFI computer. That way I didn't have to use an aftermarket controller. Which was good because I didn't have any more spare water ports after installing my water temp gauge sender and the ECU's coolant temp sensor.[/quote][/quote][/quote]
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Andrew,
I too prefer a sender that screws into the manifold or thermostat housing. I never really cared for the probe type sensors .
I noticed that you mentioned a relay for the 2nd fan. Does that mean using a controller a primary relay is not necessary?
I was under the impression that you needed a relay for each fan, or did I interpret this wrong?
Thanks for the link BTW.

Jack

 

[Longroof79]

I bought my 130 AMP Napa gold csi alternator for $20 with a $5 dollar core charge from a pull and save.. i looked for the newest looking one and then took it to get it tested right away..luckily i got one with a recent rebuild one from NAPA and it tested good. iT came off a 94 Caprice and i swapped out the serpentine pulley for a v-belt one plus a csi adapter and it bolted right in. Can't beat that! :wink:

As for the controller how accurate is it?

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You definitely scored there. I was at the local U-Pull-It the other day and saw a Caprice 9C1 but couldn't get the hood open.
Chances are the alternator was well used and abused.

Is it bolted on a Chevy or Pontiac engine? The reason I ask is, does the mount have to be modified in any way? I would also change the serpentine pulley to V-belt. Did you need a puller to get the pulley off?

 

[FE3X CLONE]

Andrew,
I too prefer a sender that screws into the manifold or thermostat housing. I never really cared for the probe type sensors .
I noticed that you mentioned a relay for the 2nd fan. Does that mean using a controller a primary relay is not necessary?
I was under the impression that you needed a relay for each fan, or did I interpret this wrong?
Thanks for the link BTW.

Jack

It's been a while since I wired the Perma-cool setup but I believe the way its setup, the controller can handle the amps of one fan, just not two. So you use a relay for the second fan.

 

[79loserbluebu]

I love my Mark VIII fan. I've got a stock 3rd gen F-body serpentine with a brand new alternator, I think it's 105 or 110A and it charges at around 13.5V with nothing on. It's alright, but it's not as high as I'd like it. With the fan on, lights on, and turn signals, the voltmeter fluctuates every time the turn signal is lit from 13 down to probably 11.8. Again, not where I'd like it to be. This is with stock wiring however, and I think that is going to be the next step.

Derale controllers are really nice. Because like Andrew said the Mark VIII draws alot of current, I replaced the weak 25A relay they give in the kits with a Bosch 75A. Works like a charm and I have an override switch if for whatever reason the temperature sensor goes wacky. The Mark VIII was tested to pull something like 3300CFM. It will keep my car cool at idle around 180° and it will drop till it shuts off, and then turns back on at 190°

 

[FE3X CLONE]

That's something else I forgot. If it's possible, its best to wire the fans so that if any relay, etc. fails, the fans will stay on.

The way I have my relay's wired for my Derale fans I am actually supplying them power at ALL times. My ECU is then sending a signal to actually switch the relays so that they turn the fans off. This way if for some reason a relay fails or just about any other part of the system fails, the fans will automatically stay on to keep the engine from overheating. This way your not left stranded if something happens to the fans.