how would i wire a dual fan setup (from a Z28) into my 1991 3.1 5-speed camaro??

i would also need a fan switch on this to turn it on when i choose...............

 

You could try doing something like this,,



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[This message has been edited by deadbird (edited August 01, 2001).]

 

thanx deadbird........it looks like it would work......although i am not the best at understanding electronics diagrams........thanx though

 

Use two relays, one for each fan. Run the power wire for each fan/relay directly to the battery. You can share one common control for both relays, but DO NOT share one common power wire for both fans through one relay (and do not wire the power through the two relays in series). You will loose voltage supplied to each fan wired that way.

[This message has been edited by TunedPort350 (edited August 02, 2001).]

 

I would agree with the above. Connecting two relays in series will reduce the voltage, primarly as a result of the voltage drop by going through an extra (un-needed) set of contacts, but the voltage drop will (should) be only a fraction of a volt at the current two fans will be drawing.

More importantly, using two relays in series will will only allow the maximum switching current to be that of the smallest relay.

As stated above, you should use one relay per fan (unless you use an appropriate size relay [power contactor, solenoid, etc.], e.g. 60-70 amperes minimum - but then that could present another problem which I will not go into here).

 

A very good point which I forgot to mention

Just in case you don't understand, what Stuart means by this is;
I don't know exactly how much current the fans draw, but let's just say it is 15 amps. If you put two 20 amp rated relays (or if you use just one relay as shown in the above diagram) with one common power wire (series wiring), than the combined fans will draw 30 amps and the relay(s) can't handle it.

If you use a seperate power wire for each relay (parallel wiring) and each fan draws 15 amps through each 20 amp relay than all is good.

[This message has been edited by TunedPort350 (edited August 02, 2001).]

 

I'd have explained the diag but I passed out shortly after posting that . Plus, I knew you guys would know what I was aiming for.

(heh, 2 relays wouldn't fit in the diag either)

------------------

• my Formula Homepage
• Collision P/Ns & Diagrams (Camaros & some of the Firebirds, more on the way)

The mind is like a parachute, it only works when its open

 

can someone make a new diagram??? pleaze??....

 

Actually, Deadbird did a very good job with the diagram he made - and I'll guess he did it from MS "paint". I tried doing a schematic, and it was very hard. He must be very patient. What I can do in two minutes by hand will take an hour using "paint", and then it'll look like a 4th grader made it.

Anyway, use the diagram he made and just connect one fan per relay. If you want to use a switch (manual operation), just connect a switch in place of or in addition to the sensor switch. Like the sensor switch, you will be switch ground to the relay coil. The other side of the relay coil gets +12 from the ignition, so they'll be off when the engine is off.

Unfortunately, I do not have a scanner, so I cannot post an image (it'd be "pretty" [professional]), but if you are still "in the dark", post what you do not understand and I'll clarify by step-by-step instructions in text (time permitting).

 

You should also add a fuse (or fuseable link) where I have added "F1" and another for "F2" in the diagram. If the ignition switched power source used for switching the relays isn't fused, then you will want to add one there as well.

[This message has been edited by TunedPort350 (edited August 03, 2001).]

 

ok, where can i get the relay and where should i located (where is my existing one located?)

thanx TP350!!!!!!!!! you rock!!!!!!

 

oh yeah, whats the best type of wire and best method of re-connecting after splicing under the hood????

 

Where to get a relay? Easiest may be Radio Shack. Look for their 30 ampere "ice cube" style 12VDC relay. I personally like Hosfelt Electronics, 800-524-6464 or 888-264-6464. No web address (what's up with that?) for quality relays often from commercial/industrial overruns or out-of-business buy outs. In other words, better than "consumer grade" (IMO) at very good prices.

Location? The factory located them on the driver's side firewall. There are normally three. One is the fuel pump relay, the other two are for each fan.

Wire? I'd go to an auto parts store (NAPA, etc.) and use 12 gauge for the fans. 18 gauge for the relay coil(s) and sensor/switches will be fine.

Both of my GM fans each draw ~49 amperes when the motor starts. This lasts for only a fraction of a second. When they get to speed, or run current, they'll each draw ~17 amperes (as measured at 14.2 volts). I would use at least a 20 ampere fuse (one per fan) located at the battery side of the power run. If you find that this fuse blows often, increase it to a 25 ampere fuse. Use an in-line fuse holder. Auto parts stores should have them that have a cover to protect it from the weather. Actually, I'd probably start with a 25 (vice 20) ampere fuse.

Best way to connect the wire? IMO, crimp and then solder. I've had excellent results using this method for years, although lately I have just been soldering my connections. Crimping by itself can make a good connection if done correctly. Dittos for soldering. Crimping is easier to do, though. The idea is to make a "gas-tight" connection. Soldering in addition to this is double insurance, but certainly not necessary (you did say "best"). I use heat shrink tubing over the connection when the splice is finished. If I'm in a hurry or don't care much, I'll just use electrical tape (not very professional).

If you really want a good seal over the connection, use heat shrink tubing that has an adhesive inside. When heated, it will cover the connection and solidify to make a permanent waterproof barrier. www.newark.com for a commercial supplier. P/N 90N6892 for 10' of 1/4" at $20. More expensive, but again, not necessary. Radio Shack or a Home Depot has consumer grade heat shrink tubing that will work okay. If you want more insulation, just use two pieces of tubing, one over the other.

[This message has been edited by Stuart Moss (edited August 03, 2001).]

 

does anyone have a diagram of what my current set-up looks like so i can just decifer what i need to buy and do???
thanx for the last peice of info, Stuart

 

nevermind, scratch that, i just took a good look at everything and figured it out