Subscribe Today

Electrical System for 87 SkiDoo MXLT

The general snowmobiling discussion. Discuss snowmobile tech, ask about trail conditions, talk about snowmobiling issues, whatever. Just keep it clean!

Electrical System for 87 SkiDoo MXLT

Postby ebulman » December 23rd, 2004, 6:01 am

My neighbours teenager has asked me to help trouble shoot a complete electrical failure on his newly aquired MXLT. He was given a $100 discount to accept the unit "as is". Personally, I think he was taken, however this is an attempt to do what I can.

Nothing works except the ignition system. All guages, lights and hand warmers do not work. It may be an intermittent problem that fails 95/99% of the time because they did work on two of his three visits to the seller. This is an Alberta location. Any ideas or source to wiring diagrams please email (ebulman@telus.net). Thanks.
ebulman
 
Posts: 1
Joined: September 17th, 2003, 9:06 am
Location: Anywhere

Electrical System for 87 SkiDoo MXLT

Postby snodrifter » December 23rd, 2004, 8:24 am

Possibly the voltage regulator is bad, which in turn would burn everything else out. First, check a couple of bulbs to see if they are any good--if not replace and change, see if they work.
snodrifter
Member
 
Posts: 22
Joined: September 12th, 2001, 11:42 am
Location: alexandria, mn

Electrical System for 87 SkiDoo MXLT

Postby ebulman » December 23rd, 2004, 8:54 am

Snodrifter: Thanks for the response. This is a "Pull Start" model, water cooled and no battery. Sorry for not saying so up front.
ebulman
 
Posts: 1
Joined: September 17th, 2003, 9:06 am
Location: Anywhere


Electrical System for 87 SkiDoo MXLT

Postby vwbuggyman » December 23rd, 2004, 9:19 am

Lemme guess..
People that didn't really know what they were doing tried to fix the electrical, and ended up making it a huge, tangled mess?
Yep, that's how mine is.

Anyway, find the magneto(right underneath the recoil starter, a big bundle of wires going underneath the motor, I think) and test to see if power is coming out of it. Call your dealer and ask them what color wire is positive and what color is ground(mine just looked it up and told me), knowing that helps(on my 96 skidoo yellow is positive and yellow w/black stripe is ground, but that's 9 years later).

If the magneto is sending out power, then its all wire tracing, probing, and re-doing lots of wires. If it's not or working improperly, you're in for a headache.

Maybe the lights don't work because the bulbs are burnt out?
vwbuggyman
Member
 
Posts: 24
Joined: December 12th, 2004, 10:08 am
Location: Troy, NY, USA

Electrical System for 87 SkiDoo MXLT

Postby snodrifter » December 23rd, 2004, 11:17 am

Yes, I know--BUT it still has a regulator. If not working, the voltage varies with rpms--instead of remaning fairly steady. High rpm will blow all the components. It is probably located under the engine mounting plate. There are other possibilities, such as broken wires, bad generator coil, etc.
snodrifter
Member
 
Posts: 22
Joined: September 12th, 2001, 11:42 am
Location: alexandria, mn

Electrical System for 87 SkiDoo MXLT

Postby craze1cars » December 23rd, 2004, 11:49 am

Just to help clarfy, it is normal for voltage to vary with RPM's, but the regulator puts a cap on it. You might get only 9 or 10 volts while idling, and then it might peak around 13 or 14 volts at about 2,500 RPM. However, if the regulator is working properly, it won't allow voltage to go any higher than that.

However, a regulator can also appear to be working fine under testing, but still allow periodic spikes which blow everything out. When in doubt, just replace the regulator. Relatively cheap ($25?), and is the most common cause of electrical problems, unless someone has already butched the other wiring all up....then you most likely have bad connections, bad grounds, etc. and you'll be chasing ghosts for a long time. Have fun!

A 1987 Ski-Doo service manual will have full schematics for this sled.
Body Armor SAVES LIVES!!!
COURTESY on the trails is CONTAGIOUS!!! Slow down EARLY for oncoming sleds!!!
ONLY pass from behind when signaled to do so!!!

THEN.....and only then...RIDE IT LIKE YOU STOLE IT!!!
craze1cars
Member
 
Posts: 47
Joined: October 5th, 2004, 10:28 am
Location: Wherever snow is deepest...

Electrical System for 87 SkiDoo MXLT

Postby ebulman » December 23rd, 2004, 5:13 pm

Thanks for all the help...you guys are good! Turns out the regulator was shorted out AND all the bulbs were burnt out. My guess is that someone thought they could fix the problem by unplugging the regulator, only to burn all the bulbs on the very next excursion into HI RPM. It appears the "Regulator" is just a stack of diodes to form a Zener like voltage clamp. This was my first exposure to a magneto based system in a long long time. Back in 59 I had a Vespa Motor scooter but I did not known anything about its means of regulation, if any.

Thanks again to all responses:)
ebulman
 
Posts: 1
Joined: September 17th, 2003, 9:06 am
Location: Anywhere


Return to SnowmobileNews Forum

Who is online

Users browsing this forum: No registered users and 3 guests

cron