RamIt

I dont know if the fans that you have are similar to the LT1 fan I have but mine pull 18A starting up or 36A for the pair.
Running at full speed they pull around 8A or 16A for the pair.
Way too much for the factory wire sizes.

MY87LT

iTrader: (2)

They are both third gen f body electric fans. I am not able to check the apms on them at this time but did check the volts with a volt meter which read at 12V or a little more both running. I may have to "splice and piggy back" an additional fan relay next to the existing one.

8t2 z-chev

I tested a set of '93 z28 dual fans and got about the same amp draw as noted above by RamIt-AFAIK,LT1 fan motors are the same as thirdgen dual fans,blades are the same.Did you measure the "12v or a little more"at the fan motors or battery?In either case that voltage is too low-should be at least 13.5.

MY87LT

iTrader: (2)

I got a bit more than 12v. I'm going to double check again but going to remove that plug connector I whipped up. Going to check direct wiring before I commit to soldering and heat shrink tubing everything up. If it was the plug connector that I spliced up then that was my issue.

-=Z28=-

iTrader: (3)

you should always have 12v or around depending on if the car is running or not or if there is a voltage drop in a system. If your wires are getting hot its cause you are pulling too many amps through the under-rated wiring. I always run a size or two bigger when wiring something like this that can vary amperage.

formula1LE

iTrader: (3)

As with all DC motors, they pull more juice as they get older and windings get worn-this overheats the contact point @ the fan motor plug and can start to melt the plastic-then begins the thermal runaway issue....let us know what you find out.

MY87LT

iTrader: (2)

I was thumbing though my 1987 Chevrolet Camaro electrical diagnosis shop manual and it shows a schematic for an auxillary cooling fan for the L69 and LG4 engine for 1987 which we all should know by now the L69 wasn't available after 1986. Either way, I am curious if anyone has this auxillary fan installed or was it just a proposed Camaro or Firebird option. Mind you, this isn't the same TPI dual fan set up. I'm thinking maybe it was like on the C4 Corvette that had one mounted in the front of the radiator.

8t2 z-chev

interesting-at first I thought that was for the little blower added to certain late carbed 305s to deal with the vapor lock problem,but indeed looks like it's for an aux.radiator fan,perhaps a ~11"one like the C4 'vettes.

MY87LT

iTrader: (2)

Ok so this plug setup didn't quite work. I spliced together the wiring instead. Now the wires aren't hot like they were but the relay at firewall did get a bit warm. Next plan is to get a pigtail harness to piggy back a second relay with the first to hopefully spilt the power. Then if that doesn't work, back to electronics 101. Lol

MY87LT

iTrader: (2)

I think I succeeded. I went ahead and spliced in a second factory type fan relay with two new pigtails onto the existing wiring. So far, the wires are not getting hot anymore and both relays seem to be cool to the touch as opposed to the single relay was getting warm. I just had the fans on constant for five minutes. Next test will be to allow them to run for 15 minutes and then 30.

MY87LT

iTrader: (2)

Drove my car over the weekend and no ill effects with either the fans or the relays. I'll do one more run before I properly secure the wiring with correct solder and electrical tape along with installing a new fusible link wire. Then, I will call it success.

MY87LT

iTrader: (2)

Here is how I hooked up the old and the new relay for the dual fan set up. The only thing I am going to change is replacing the fusible link to an in line fuse for easy replacement in case it goes out while I'm on a drive.

Also got in the mail a new old stock pusher fan set up for the 1984 to 1989 corvettes. Going to be hooking that up in front of the ac condenser to come on at 220 if the primary fans decide to fail.

MY87LT

iTrader: (2)

UPDATE:

Corvette pusher fan was not needed. The second relay which I spliced with the original first really isn't doing anything but just acting as a dummy (or spare really lol).

My nephew is an industrial electrician and checked out my wiring work. He said everything is fine but overkill. If I wanted to, I can still hook up the second 20 amp relay to the other fan but since at fan start up and regular running, both fans are only pulling 14 amps.