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Discussion Starter #1
Wanted to improve the cooling on the Fleetwood as it's already over 100F in Vegas.
Not just the engine, & coolers but to help the A/C performance.

It came with a 240w on the drivers side and a 150w on the passenger side.

Had an extra 240w high speed fan.
So I removed the low speed 150w pasenger side fan.
Blades looked the same.
Motor was much bigger on the 240w.
The brackets between the left & right had a different orientation.
Also the bracket on the 240w was about 2" wider across in the center where the motor mounts.
It really wasn't feasible to put the larger motor in the passenger side bracket.
After you made room by cutting a larger circle for the larger motor their would be little bracket material left.

I installed the drivers side high motor bracket in the passenger side.
At 1st you think the 3 arms of the bracket are about equil, but they're not even close.
The only way the blades would clear is if the bottom slide in bracket was rotated near the upper transmission lines & A/C lines. For that bracket I took a 3/4" x 1/8 piece of AL & made a extension of the radiator mounting point.

The bottom bracket I made out of some garage track / shelf bracket material. Maybe it was 1x2" angle.
Mounted that to the core support on a rubber cusion mode from an old hose.

Top bracket used the factory location.
Factory plug still worked.

105F out and never got past 199F even at 2,000 RPM.
A/C high pressure was 230 PSI at idle or 430 PSI at 2,000.
Little bit more load on the alternator.

You can hear and feel the difference.
Didn't check but in theory both fans would draw 20A each, or 40A combined.
VS 12.5A & 20A before (32.5A combined).
Some say a rule of thumb is 1000 CFM per 10A.
So before it would have been 3250 combined CFM.
Now 4000 combined CFM.
Afain that's a generic number that dosent factor a lot of things.
What ever it is I got 23% more of it.
 

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Discussion Starter #3
No. But with the A/C on they run constantly here.
The 1st fan kicks on with the A/C.
Once pressure builds up on the high side the 2nd fan kicks on. Maybe 30 seconds after start-up.
Which gives the alternator at least a moment before the 2nd turns on.
 

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Discussion Starter #4
Fan on the top is the larger stock 240w left fan.
With mounting bracket to bolt to lower core support.

Fan on the bottom is the stock 150w right fan.


582053



Completed pic with duel 240w fans.
582054
 

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Well! I had eye-balled doing exactly the same thing, and applaud your work-around for the mounts. We don't get nearly the sustained heat here in the Midwest, and I settled on just having the temps tuned down, along with replacing both motors. The write-up is good, and post up any more pics you took of those modded brackets eh.
 

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Discussion Starter #6 (Edited)
Start by loosely attaching orignal top fan bolt in stock top radiator position.
Make sure out od the 3 plastic mounting legs the one without a bolt hole faces the trans upper cooler line going in the radiator.

Orignal fans mounted only to the radiator.
To make it simplier I mounted the bracket to the lower core support.
Just in case I used a piece of rubber between that bracket & the core support.
The rubber spacer was made out of an old cooling hose cut to the size of the bracket with 2 3/8" holes drilled for the mounting bolts.

A pic of the lower bracket.

Side with 4 holes mounts to the core support.
Held in place with rubber spacer made & eyeballed holes drilled.
Paint touched up bare metal holes.
The bracket holes were reamed out a bit to align with the holes drilled.

With the bracket & rubber in place mark the hole to be drilled & taped in the top of new bracket for attaching the lower plastic fan arm.
Holes is a hole drilled & taped 1/4-20.

Used a 1/4-20x1/2" hex bolt with 1/4x1" washer to mount the lower plastic fan bracket to the 90 metal bracket made.
Also used 2 1/4-20x1/2" hex bolts & nuts to bolt the lower 90 bracket thru a section of rubber to the lower core support.

Top corners of the 90 bracket were cut down so it wouldn't block air flow.
All corners smothed off & quickly painted.



582083
 

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Discussion Starter #7
The side bracket next to the cooler lines I cheated a bit.

In the plastic arm near I marked a 1/4" hole almost inline but about 8" above the old radiator fan side mount.
Had to remove to drill the 1/4" in the plastic arm.
Put a 1/4x20x1" or 1 1/4 (forgot which) bolt thru the plastic arm with a 1/4x1" washer.
Install fan with top & bottom mounts.

Take a piece of 3/4x1/8 AL stock.
Drilled a 1/4" hole in 1 side.
Hang the AL bar from the 1/4" bolt in the plastic arm.
Mark where the other side lines up with the radiator side mount.
Remove the bar & drill the hole on the other side.
Cut the extra bar off.
I rounded all the corners & painted fast.
Bolt the bar between the old radiator mount with orignal bolt to the new 1/4" bolt in the plastic arm with a 1/4x1" washer & 1/4-20 nut.


582084
 

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1995 Cadillac Fleetwood
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Using 2 240w fans is just plug and play with a dual electric set up? Besides the extra brackets needed, the larger fan doesn't tax the system or the alternator in any noticeable way? I know you mentioned it is a larger draw, but nothing the system can't handle?

Also, the OEM dual electric set up was 1 240w and 1 150w?

Well! I had eye-balled doing exactly the same thing, and applaud your work-around for the mounts. We don't get nearly the sustained heat here in the Midwest, and I settled on just having the temps tuned down, along with replacing both motors. The write-up is good, and post up any more pics you took of those modded brackets eh.
The driver's fan (240w) is only supposed to come on when the A/C kicks on AND when it's above a certain temp? Both factors have to exist, correct? What did replacing your motors do for you?

Had a 10+ hour drive on the highway in some heat yesterday (with AC on) and my 240w never seemed to come on. Would the mechnical + highway speed be moving enough air to not trigger it to come on?

The PCM tune you mention just brings the temps lower for start up, which GM left high for emissions purposes, I suppose. Does it affect the fuel economy negatively with the upside being a cooler engine?

Thanks!
 

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Discussion Starter #9
There was 3 LT1 cooling options:
Base 150w R/H primary & 100w L/H secondary
Extra capacity cooling V03 150w R/H primary & 240w L/H secondary
Heavy duty cooling V08 mechanical clutch fan & 240w secondary

The electrical system was designed the same on both primary & secondary fans reguardless if it was equiped with a 100w, 150w, or 240w fan. They were all on 40A circuits. 10awg to the relay. 12awg to the fan motor then ground.
Same relay part used.
The only exception was if it had the heavy duty cooling V08. In that case the car only had 1 relay & 40A fuse.
Could convert from base cooling to extra capacity V03 cooling by just swaping the left secondary fan assembly (motor, blade, bracket).

The secondary fan comes on at a certain temp or A/C high pressure.
I don't remember what those numbers are right now.
With the A/C on and hot outside the high side pressure builds fast.
As the fans kick on the pressures lower.

It's hard for me to tell when the fans kick on sitting in the car unless I have a scanner.
Never tried a highway drive with a scanner.

Parked & running outside the car I can her the fan but again without looking it's hard to tell what's going on.
I would just say it's a bit louder. I don't drive the car enough to remember the different high / low / before / after.

If you have the V08 mechanical fan option it may be possible to swap ECM terminals 10 & 11.
To make the secondary electric fan run on lower primary fan temp / pressure.

My best guess is if anything it would help fuel econimy if anything is noticable.
Lower intake air temp = more power.
Couple more amps drawn off the alternator wouldn't rob much power.

It adds an 8A load to a 140A alternator.
 

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1995 Cadillac Fleetwood
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Very good, thank you so much! Interesting that they had an extra cooling capacity add on; I never knew that was an option and obviously a valuable one. I have been trying to monitor my 240w fan and I have never seen it turn on; it's not that hot here at the moment but I keep checking to see if it actually works. All I ever hear/see is the mechanical guillotine that is the primary fan.

If you have the V08 mechanical fan option it may be possible to swap ECM terminals 10 & 11.
To make the secondary electric fan run on lower primary fan temp / pressure.
When you say swap ECM terminals, what do you mean and how would I do that?
 

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Discussion Starter #11
On the red ECM 32 pin connector:
Terminal 10 Secondary fan relay, dark blue .35 wire #335
Terminal 11 Primary fan relay, dark green .35 wire #409 (not used with V08 heavy duty cooling)

In theory disconect the wire 335 from terminal 10 and install in terminal 11.

GM connector 12129025 if you didn't want to release & reuse the old terminal.
 

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Discussion Starter #12
Update

Didn't notice the problem at first.
Voltage was adiquite at 13.6v idling

On a hot day with both fans running and the A/C blower on max you could hear the voltage fluxuation between idle & driving.
Didn't have the lights on, but probibly would have seen there too.
IDK if the alternator is regulating the output due to the temp or if it's output is weaker from maybe 1 bad diode.
The alternator was a used but recently rebuilt alternator about a month ago.
Clean with the sticker, but still disassembled and checked everything not too long ago.
Don't remember the exact readings, just that it would put out around 140a at 14v at 2000 RPM.

So instead of putting the old fan on or upgrading to a higher then stock 140A alternator I took a different route.
Got a 1 7/8" pulley off Ebay for $13 to replace the 2 1/4".
That's all it took.
Now it's about 14.4v at idle all day long with lights, both fans, & blower on high after a restart.
It's putting out about 100A at idle compaired to around 85A before.
Didn't try to put more load on it to see what the max amps is now.

Did the pully math.
Went with outer diameter, not outter belt grove because it was easier to measure.
6.5" Crank
2.375" Stock Alt pulley
2" New Alt pulley

Stock ratio 2.74
New ratio 3.25

600 RPM stock = 1644 Alt RPM
600 RPM now = 1950 Alt RPM
They say the alternator dosn't really kick in till about 2000 Alt RPM

5000 RPM = 15070 Alt RPM
5500 RPM = 17875 Alt RPM

Some places recomend no more than 18000 Alt RPM
 

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Discussion Starter #14
The blades aren't touching, but they're close.
In a perfect world the drivers fan would be a bit more to the left, but stock they didn't put it right along the radiator edge.
The new fan is closer to the radiator.
Srock fan is a bit more off.
That give the clearance to avoid blades hitting each other.
582543
 
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