1984 Sprintfire

[Sprintfire84]

Hello all,
Just wondering if anyone can tell me if the handwarmers on a 1984 Sprintfire are wired in Parallel or in series? The electrical schematic on this site doesn't really show anything about the handwarmers. It almost looks as if it would be in parallel since there are 2 leads coming from the switch, and what looks to be 2 grounds running down to the frame or somewhere below the CDI. Mice got to this sled before i owned it and I'm trying to get it back to normal. Thanks!

[Sprintfire84]

Hi again, just to follow up and help anyone with this problem in the future, the handwarmers are definitely wired in Parallel, not series. I hooked them up in Parallel and they work like a charm.

I do however have a new question - would a bad voltage regulator cause a digital multimeter to go crazy, jumping numbers around from 0-20, so fast i can't even see them, when i'm not even probing anything? Seriously, i'm standing by the machine (running, of course), at idle with the hood open and not touching anything, and the multimeter is doing this. When i shut the machine off, it stops. I've tried a few other sleds that i have, but none of them do it, just this Sprintfire. There must be stray voltage coming from somewhere, but would the voltage regulator cause this? Again, I don't have any of the leads from the multimeter touching anything. The reason i was checking voltage is because neither headlight or tail light/brake light work. I've only checked the headlight bulb so far and it was blown, so that is why i wanted to check voltage on the regulator.
Any ideas or thoughts are appreciated!

[SS440-80]

First a question. Do you have your multimeter in AC? Because if you have it in DC and measure, you will get crazy reading.

But yes, it could be the voltage regulator, and since your front bulb is blown and probably the rear bulb too, I would guess that your voltage regulator is shot. If you disconnect the regulator and measure the voltage you should get over twenty volts when you raise the rpm just a little bit above idle.

[Sprintfire84]

First a question. Do you have your multimeter in AC? Because if you have it in DC and measure, you will get crazy reading.

But yes, it could be the voltage regulator, and since your front bulb is blown and probably the rear bulb too, I would guess that your voltage regulator is shot. If you disconnect the regulator and measure the voltage you should get over twenty volts when you raise the rpm just a little bit above idle.

I'm pretty sure i tried both, but i will try it again. Would it go crazy even if I'm not touching anything? It's almost like the multimeter was possessed, lol.
I did get a chance to look at the tail light bulb and yes, it was blown. I will order a new voltage regulator and start there. I do already have the old one off. Would you happen to know if the JD part number AM52886 would be the correct regulator for the sprintfire?
Also, can you tell me what the little box bolted to the front panel, next to the key switch is? It has 2 or 3 connectors and wires going to it. Could that be a resistor? Thanks

[AirborneX4Special]

Sprintfire regulator p/n AM55487

[Sprintfire84]

Sprintfire regulator p/n AM55487

Thanks, i found an online parts manual and it said that snowfire and sprintfire snowmobiles take p/n AM55296 for the voltage regulator. Is this correct or is it the same regulator as the part number you listed?

[AirborneX4Special]

My source is an original Deere parts manual PC 1872 Snowfire & Sprintfire snowmobiles dated 28 Nov 83 (Revision)

[Sprintfire84]

Okay, thanks. Maybe that revision has something to do with it.
I had a chance to search around, and there's even an online shop service manual download. It did say to unhook voltage regulator, install new bulbs and ONLY run at idle. If the bulbs light up, replace VR. If the bulbs don't light up, test lighting coil. Says if you run above idle, you will blow all the bulbs out, which makes sense, according to SS440 who mentioned it would shoot up to 20 volts.

[AirborneX4Special]

That's pretty much what the service manual indicates. They call the lighting coil the "alternator".

[Sprintfire84]

That's pretty much what the service manual indicates. They call the lighting coil the "alternator".

I apologize, I read through the online manual again and you are correct, p/n AM55487 is correct. I was in fact reading the Snowfire electrical parts list. I needed to scroll down further to reach the Sprintfire electrical parts list.
With that being said, does anyone have a clue where I could purchase AM55487? I’m not having any luck.
Thanks in advance!

[nick80lf]

The little box by the key that you mentioned is the rev limiter. It serves 2 functions....will not alow the engine RPMs to get high enough to engage the clutch if the switch in the throttle block is not depressed.......prevents the engine RPMs from going too high.

Most just unplug the rev limiters. I do have them functional on my liquifires but the limiter on my Snowfire is not functional. On the liquifires the limiter seems strange. If you quickly rev the engine and let off the throttle the engine will skip once because the rpms don't come down fast enough to make the box happy. Sort of sounds like the engine backfires or has a mis.

[nick80lf]

Before I started buying voltage regulators I would polish the metal mounting tab on the regulator (this is the regulators connection to ground). Also make sure the ground going from the motor to the chassis has a good clean connection with no broken wires.

Electrically i believe the typical vanilla single wire voltage regulator would work. Like this one: https://newbreedparts.com/products/volt ... sprintfire

I'm not real familiar with the sprintfire but you might need to change the connector on the end of the regulator in the link above to match. Liquifire, Snowfire, and Sportfire all use a 1/4" male spade connector on the regulator wire.