View Full Version : Wiring Diagram for Acc-1 Switch

09-01-2004, 12:34 AM
My heater is hooked up to Acc-1 rocker switch which is a two position switch (on and off). The heater has three wires which controls the fan speed, yellow-low, red=med, and orange=high. The Acc-1 rocker switch uses the red/medium. I thought it might be nice to be able to have two fan speeds, med and high, so I went to the dealer and bought a switch which is three position rocker switch that match my other switches and is similar to the bilge switch, e.g. rocker position in the middle is off, rocker position up manual bilge, and rocker position botton is automatic bilge. This switch is black and has a small circular green light on the upper part of the rocker switch. On the back of the rocker switch there are 5 male prongs. I can't for the life of me figure out what all these prongs are for. Anyone have a wiring diagram or input how to hook this up for the application I set forth above. Thanks.

09-01-2004, 06:20 AM
I can't help you on the switch (it's been too long since I installed my heater).

I hooked mine up so the acc1 turned the voltage on or off to the 4 position (off-low-med-high) rotation switch that came with the heater.

Having said all that - If I were to do it again, I'd forget about about the rotating switch & wire it up to high all the time. We have NEVER used anything but high in the 3 years of owning a heater.

sorry I couldn't answer your question directly.

09-01-2004, 07:27 AM
I can't imagine using anything but high either but I would imagine that the five prongs are batt+, GND and the three desired speeds low, Med, High......but i could be wrong.

09-01-2004, 03:53 PM
Do you know what type of switch it is?

Like, DPDT or SPDT

A picture of the back would help.

I would guess it is a SPDT three way rocker if it only has 5 terminals. I would also guess that you will only be able to use two of the speeds (sounds like medium and high are the way to go). Your upper most and lower most terminals shoud connect to your desired fan speeds. The two inner terminals should connect to your source +, and the last terminal probably off to the right should be your ground for the indicator light.

This is my best guess not seeing the back of the switch. A Fluke would be ideal for testing if you have access to one.

09-01-2004, 05:00 PM
Agree with Diesel.. without seeing/playing with it, it's hard to tell.

two of the terminals may be for the indicator light, allowing you to choose what circuit lights it up, making it a single-pole double throw, or, it could be single-pole, triple throw as Diesel describes..

09-01-2004, 07:53 PM
Neil & Diesel,

Pictures attached, however, I don't see any reference to the brand/manufacturer of the switch.

Top of Switch from behind


I did hook up my Fluke, and probed for continuity, but honestly, I never really understood how to use that device:o Here is what I was able to figure out. Taking the same prong layout as above with alpha letters


1. With rocker switch in up position, continuity results with the Fluke (-) lead on E, (+) on D, A and C;
2. With rocker switch in down position, continuity results on A and C and B and D
3. With rocker switch in middle position (off), continuity results of A and C.


All in all, this means nothing to me whatso ever,.:D

09-02-2004, 12:48 PM

This is interesting. First a couple questions -- 1. Do you know what the function of the light is? (Is it supposed to go when you turn on your NAV lights, or when you turn on the heater?) 2. Are you sure you checked continuity right in #1 ? Sure you didn't short across anything?

I think A & C go across your light -- that's why you always have continuity. I'm a little confused about #1, I think you should see D to E and A to C (maybe that's what you're saying)

So, I think the hookup should be:

A: Switched hot from Nav lights
B: Output 1 to heater (on in down position)
C: Ground
D: Hot all times
E: Ouput 2 to heater (on in up position)

if you don't want the light to light up, you don't need to worry about hooking up nodes A and C.

09-02-2004, 01:02 PM

I think Handycm's got it right. A&C are for the lamp. D is where your + power is supplied, leaving you B&E to connect to the heater.

If you do connect up the light, connect it up to the orange, since I'm sure that "high" is the only fan speed you'll ever use...

09-02-2004, 01:14 PM
Hardycm and Neil, thanks so much for your help. hardycm, I not sure about #1 as well, but I think the both of you figured it out. The switch is just like the Nav/anchor switch and the auto bilge switch, only difference I can tell is that the bilge switch, when in the auto position, the little green light does not light up, probably so you don't drain your battery if you leave your boat in the water for extended period. The nav/anchor light switch will glow green in the up or down position of the rocker, which is how I would like to hook it up for the heater function. Yes, I want to have the high fan speed (orange wire from the heater) operate when the rocker is in the up position, and the med fan speed (red wire) when the rocker is in the down position, both of which will make the green light glow so I know it is on.

I took a peak at the other switches from the dash, and if you have not looked at them before, you won't beleive how they've done it. There are lots of jumper wires from switch to switch (in series) and is quite confusing. I'm not going to mess with any of those so I'll try to wire the new switch independantly or just bag if I can't figure it out and just hook the existing switch to the orange wire for hign fan speed only. Thanks again for the help, and I'll let you all know if I'm successful.

09-02-2004, 04:17 PM
Sorry I didn't check back sooner but it looks like the guys have you going in the right direction.

Good luck...................

09-02-2004, 07:56 PM

Yeah, let us know how it turns out. Assuming my scenario from earlier is right, I'm not sure you can have the light on for both the up & down positions of the rocker, unless you put a diode in the line. If you put in a jumper from B or E (whichever is the orange wire), the light should lite up in high only (much like your bilge pump). You may want to look at the hookup for your nav light switch for some guidance.

09-03-2004, 11:35 AM
Hardycm, I think you are absolutely right about the prong layout above. I spent a couple of hours under the dash, and the current wire setup for the nav/anchor switch should work for my intended use of the ACC-1. I didn't have all the necessary electrical connectors/jumpers, so I was unable to really move forward with this, but it will be a PITA to either remove the switch or the entire panel that all the switches are attached to. If I'm successful with that it should be straight forward install. In the mean time, I hooked up the existing ACC-1 switch to the orange wire (high fan speed) off the heater fan, and what a difference than the red wire (low fan speed). High fan speed puts out much more cfm! I agree with all of you that most likely the high position will be used 99.9% of the time, so I may just leave it this way. But you know, once you have something on the brain, its hard to back away from a challenge! :)

09-03-2004, 12:19 PM
Kell, the fan speed may be a kind of a balancing act. If you run the blower on high speed, the air may not be very warm coming out of the vents, especially at lower rpm.

If you haven't done so, order the 1.125" low speed heat kit from Heatercraft (I posted on this in the old forum). You'll be amazed at the difference it makes..

09-03-2004, 01:40 PM
"Low speed kit", guess I'll have to search the old site for this modification. I'm assuming this kit will provide more heat at idel speed? Any ramifications on keeping the engine cool? This must divert more hot water through the heater system. I'm constantly reminded by all of you what a great site this is. So much knowledge, great advise and expertise! Here comes a winter project, low speed kit for the heater! :D

09-04-2004, 12:34 AM
Yup.. Works great.

You want kit H-424 from HeaterCraft, which I think is $30.00 (which is a lot for one y-pipe and a brass plug, but, what the hey, it works).

Real easy to install as long as you're comfortable cutting the raw water intake hose. No ramifications I've heard re: keeping the engine cool.

I originally found out about the kit on the Malibu Boat Owner's forum and then got a 1 1/4" one from HeaterCraft.