JamesC

iTrader: (5)

I need a tutitorial on how to make the converstion on an 85 LG4 with air con. I'd like the set-up to work like stock. Any help would be appreciated.

JamesC

CamaroMike

Get the dual fan setup buy the Painless fan control kit and you are mostly done. The problem lies in the A/C. Thirdgen climate controls are set up to power the A/C and fan relays, not ground them. The Painless kit works by a grounding sensor that can't be signaled by any factory device on the vehicle. You will have to rig up a manual fan switch so that you can ground the Painless relay whenever you run your A/C. Kinda of a pain in the butt but if you don't rig a manual switch then you will lock your compressor due to high pressures in the condensor. If anyone has a suggestion as to how one could ground the painless relay with a factory device ,with the A/C on, that would be great (without using a second relay of course).

quadgoat

iTrader: (1)

I'm afraid I'm going to have to disagree there. On my '84 T/A originally equipped with an L69 with single electric fan the climate controls definitely supply a ground to the fan relay to activate it. I've actually got dual LT-1 fans rigged up in my car now and the way I wired everything up I can definitely get the fans to turn on by switching the A/C on...it grounds a wire which activates my relays. Maybe it's different from year to year, but on my '84 it's a ground and I believe the wiring diagrams show it that way. I definitely agree on the Painless setup for fan control, I just helped a friend of mine swap a TPI motor into his ElCamino and he used one of those Painless kits for fan control, it worked real slick! I've also been very happy with my CSI digital temp guage that has a built in fan control that you can set to turn your fan on at whatever temperature you desire. Anyway, guess that's my .02, it shouldn't be a hard swap for ya once you get all the parts and pieces together, just take your time when you wire it up(separate power supply and relay for each fan, etc.)!

-Paul

CamaroMike

Quadgoat,

James C. was talking about going from an LG4 Mechanical fan to a Dual Electric. James has no fan relay to begin with. So there is no system set up to ground out a relay there at all. I would agree that most factory fan relays are ECM grounded but that does not seem to be the case with my 84 wiring diagram. James does however have the Throttle Kicker relay that is acitvated by a voltage signal (light green wire) to use as a fan relay activator. I am actually going to use a second relay to activate my fans (during A/C operation) with this voltage signal. Besides, I just looked at the factory wiring diagram for the L69 and the same green wire that powers the compressor and throttle kicker relay sends a voltage signal to the fan relay upon A/C activation. You might be looking at the throtle kicker relay which has a ground wire that goes to the ECM but that ground won't work too well if your ECM has been removed as it is on my Camaro. Obviously, the throttle kicker has dual functions. One mode during A/C operation to raise the idle and as a ECM controlled Anti-Diesel solenoid. Just a thought.

BTW, James you only need one relay kit for the two fans. The Painless relay is rated for 30 Amps and 2 fans should never exceed that. I have been using one relay for years with no trouble what so ever. Most factory fans run about 8-10 amps each. Just use good 12 gauge wire and you should be OK.

quadgoat

iTrader: (1)

CamaroMike,
I realize what he's trying to do, and perhaps the control head for the LG4 is different than the L69 (Obviously the wiring is since the LG4 doesn't run an electric fan ) but I'm looking at my factory shop manual for my '84 electric fan and it is not controlled by the computer at all. It is activated in two cases. First case is if the fan switch closes to ground (grounds the fan relay) at 238 degrees, second case is if the A/C control head grounds the relay (actually tapped into the same wire that goes to the fan switch in the cylinder head). The fan relay receives battery power through a fusable link and the relay is initialized when the key is turned on through the choke heater fuse (also powered the hood louver circuit and the computer command control on my 'bird). I don't know how he's going to end up setting it up, but unless the control head is different, he should be able to get a ground signal from there to initialze his relays when the fans are turned on. The control head does also supply a power signal to turn the compressor on when the pressure switches in the A/C system are all closed, I'm not arguing that fact, but just saying that the control head (at least on my L69) supplies a ground also.

The reason I recommended going with two relays is not because of what the fans draw when they're running, but because of startup draw. I was told that the LT-1 fans I'm using draw about 25 amps a piece at startup and 15-20 amps a piece while they're running, so I'm running a separate relay for each fan. Maybe the stock thirdgen fans don't draw as much, but I wanted to be on the safe side that's all.

Anyway, sorry for barging in, but I just wanna make sure that correct information is out there. I'm not saying you're wrong, because you're definitely not, the control head does supply power for the compressor circuit, but it also supplies a ground, that's all. Hope my post made sense, let me know if I can clarify anything, and good luck!!

-Paul

CamaroMike

I agree about the control head. I am going to go home tonight and see if I can get a ground off of the control head myself. Might just do the dual relay thing.

JamesC

iTrader: (5)

Hey, Guys,

This from Willie's Total Fan Control articles, concerning a single fan: "the fan is controlled mechanically through an in-cylinder head thermal switch. It is designed to turn on when coolant temperatures reach 222 degrees (or higher) or when the ac/c is turned on. There is no ECM control for the fan on single fan applications." Does this mean that I could wire up a single fan without problem? Keep in mind, however, that I'd prefer the duals? At any rate, I'm an electronics knucklehead, so keep that in mind with your explanations

JamesC

quadgoat

iTrader: (1)

That's right....no ECM control with the single fan setup, the dual fan setup had one fan controlled by the same method as a single fan setup (thermal switch in cylinder head or A/C control head) and the second fan was controlled by the ECM. I'm pretty sure that's how it was set up. I also think that both fans were on when the A/C was turned on...but I'm not sure on that. You could set up two fans with two separate thermal switches (different temps for example) so they'd turn on separate from each other, and both turn on when you turned the A/C on...I'm not sure if that's how you want it set up or not....but it would be doable without too much diffaculty.

-Paul

CamaroMike

Quadgoat,

Spent 4 hours last night messin with my cooling fans. New motor and adding a second relay. My cooling fans pull 9.5 Amps each while running but in excess of 20 Amps each during startup. Startup is a little high for one relay with 2 fans. Although, I never had any problem with one relay. I pulled out my control head and there is no provision for grounding any part of the A/C system to activate the fans. CR@P! Since I do not use my Throttle Kicker Relay I am going to modify it to convert a positive signal to a ground by rearranging some wiring. That way when the A/C is on the two fan relays are activated. Pretty slick idea just hope it works. If you want more info on the relay mods, let me know. I can give you a wire by wire play! I am going to hook both fans up to the back of the alternator by splicing two 12 guage wires into one 10 guage. Do you think 6" of 10 guage wire is enough for the two fans? I would hope so, I think 10 guage wire will support like a 100 amp alt but others opinions are nice. Let me know.

quadgoat

iTrader: (1)

After I posted I looked at an LG4 control head that I have out in the garage and found out the same thing you did...no grounding provision....bummer that the LG4 and L69 control heads are different. I imagine that your 10 guage setup would work fine...I've got two separate 12 guage leads (one for each fan) and they've worked fine for me. The way I have mine set up one fan is controlled by my CSI digital temp guage, and the other one is controlled by a Hayden fan control that has a probe in the radiator fins. Overall it works out pretty well, each fan has its own relay so I don't have to worry too much about startup draw. As long as the single relay has worked for you in the past I wouldn't hesitate to stick with it. It'd be interesting to know if the LT-1 fans I'm running draw more at startup or while they're running than the thirdgen fans do. Anyway, sorry the LG4 control head won't supply ground...good luck with the rest though!

-Paul

CamaroMike

Quadgoat,

Finished the "Birdsnest" last night. WOW! Dual relays make a big difference! The fans seem to spin alot faster now. Much more air flow off the battery alone as compared to one relay with the Alternator. My wiring magic worked with the throttle kicker relay! Now both fans come on when the A/C is turned on! :rockon: Just thought I would share.

JamesC

iTrader: (5)

Ok, CamaroMike,

Quit smilin' and tell me (and others) how you've hooked everything up so we can follow in your footsteps :hail:

At the least, I'd like to use a thermal switch to automatically turn one fan on and employ a manual switch to turn the a/c on. Is this a simpler approach?

JamesC

CamaroMike

You guys ready for this!

From the start,

Two relays for the fans. One is the Painless kit with thermal activation switch, the other is a Painless kit without the thermal switch. Both relays use one 12-gauge wire to get power off of the alternator. The other 12-gauge wire on the relays go to the fan. The grey wire on the relays goes to a fused switched ignition source. I came off of the fuse box. The 4th or black wires get tricky. Both black wires go to the thermal switch; I also have a manual fan switch (just in case), and the throttle kicker relay.

The throttle kicker relay on the drivers side firewall for LG4 equipped V8's (to the best of my knowledge) is a power-activated unit that is used as an anti-diesel solenoid and under high loads when the A/C is on. Now the technical stuff. There are 5 wires going to the throttle kicker solenoid. The are from left to right as follows. Light green, brown, pink/black, black, dark blue. Light green is a 12V switched power source from the climate control head, brown is what I believe to be something like 8V from the choke fuse (this allows the throttle kicker relay to be part way out during running operation so when the engine is shut off the throttle closes a little and prevents dieseling), pink/black is 12V switched from the fuse panel and powers one side of the relay, black is an ECM ground which activates the relay, and dark blue goes to the throttle kicker solenoid. When the relay is not activated the brown wire powers the throttle kicker solenoid partially, but after computer activation the green A/C wire gives a full 12V to the throttle kicker solenoid to raise the idle. (Not 100% sure that’s how it works but I think I’m close. The brown wire is a bit confusing because if it did provide 12 volts the throttle kicker would be at full extension all the time.)

Here's where the magic happens.
This procedure will only work if you are no longer using your ECM and old throttle kicker.

Cut the light green, pink/black, and brown wires going to the throttle kicker solenoid about 3-4 inches down. Leave the black and dark blue wires in tact. Do not cut them too close to the connector or you’re in deep poo! Take the light green wire from the wiring harness and connect it with the pink/black wire of the now separate connector that goes to the throttle kicker relay. Under the passenger side of the dash ground the black wire that used to go to the ECM. The light green wire on the connector will now be hooked up to the ground wires of the two fan relays and the dark blue wire will be grounded to the intake manifold. Leave the brown wire on the connector and wiring harness alone and cap them off as well as the pink/black wire coming from the wiring harness. This arrangement will activate the throttle kicker relay any time the A/C is turned on, grounding your fan relays. Now your cooling fans work like factory.


Sorry about the length but this is a little technical.

cocacolakidd

iTrader: (6)

Hi guys, I have an 84 Z-28 with the clutch single fan and OEM Radiator. I'm going to the dual fan setup with an aluminum radiator. I have heard of the "Painless" controls/wiring setup, and this is what I think I will go with...Question ? where does one find the "Painless System"? I would like to check it out as every one says it is a good/ reliable way to wire the dual fans. Thanks, Ed.

CamaroMike

James,

You never said if this helped you or not. Let me know.

JamesC

iTrader: (5)

Hey, CamaroMike,

I've assembled parts, but I haven't yet messed with it. As a matter of fact, I may wait until next summer. My A/C compressor shot craps (I'd converted to 134, which IMO wasn't worth the effort, so I'm reconvertiing to 12). I'd like to see what kind of changes that brings about in advance of going electric. The car runs very cool, except in traffic, which doesn't really affect me that much since I live in the boonies near the NE line.

JamesC

cocacolakidd

iTrader: (6)

I wanted to reply sooner but it has been very hectic here (we are trying to get out of here for vacation this weekend- to be gone for two weeks)
I think I’m going to eliminate the air-conditioning altogether as I do not use it even when it is hot here (4 or 5 days here it will get up to 105* during the hot part of the summer every other year or so). I have visited a couple of sites to study the Painless system (Jeg’s mainly), and I think the "Painless" system is just what I was looking for. They have a regular system, and an add on for dual fans, that will set-up my system just right. I may also run a manual switch that will switch on both fans just in case. Thanks for all of the insight and information. If I do decide to keep the “air” your method above sounds like the way I will wire up the system as the anti-knock is disconnected now and not used (black and green wiring still going to the compressor head etc) . With the aluminum radiator and dual fans and eliminate the “air”, I may have my heating under control…hope, hope. Thanks, Ed.

JamesC

iTrader: (5)

I ran across this relay (PRM-19002) today. I'm unsure how it works--but would this solve my problem? That is, could I have one fan turn on with the thermal switch and the second fan come on using this relay?

http://store.summitracing.com/defaul...9002+&x=14&y=8

JamesC

JamesC

iTrader: (5)

Here's what I finally did.

https://www.thirdgen.org/techbb2/sho...hreadid=309711

JamesC