Husqvarna 272XPG - Heated Handle Wiring Help

[hacskaroly]

While perusing the local dump, I found a Husqvarna 272XPG sitting on the ground just waiting for me (it was sitting next to a Stihl 046 and a few little Poulans - yes, they all came home with me too!). The saw has been a mucky mess to get clean, but has good compression (no scoring on the piston from exhaust side). While taking it apart to clean, I found that someone has been in the saw before and clipped the wires to the heated rear handle. The front handle does not have any wires or a hole where they should be coming from, I am assuming that it has been replaced. The generator is still there with its single wire ending in a connector. Pictures to follow:

Rear handle wiring, switch has short black wire (clipped), the other short black wire connected to the left side heater broke off of the switch, the blue wire (looks green in image) was also clipped at some point.

Generator wire tucked into its trough, some exposed copper, needs to be repaired.

Husqvarna 272XPG IPL diagram. Shows generator with single wire, front handle with two wires and the switch with two wires - one connecting to the left rear handle heater and the other to ground possibly?

Looks like from the diagram I have the following parts specific for the XPG:

• 501 62 96-05 (G) - Right/Left rear heating element
• 503 21 29-05 (G) - Right/Left rear heating element wiring eyelet screw
• 501 59 74-04 (G) - Metal tube (conductor between heating elements)
• 724 79 51-02 (G) - Screw (right/left)
• 501 52 66-02 (G) - Switch with wires and eyelets
• 501 80 24-01 (G) - Generator with single wire
• 725 52 93-45 (G) - Screws x 3
• 501 77 82-01 (G) - Ignition coil?

Missing:

• 501 53 45-04 (G) - Front handle with wires and heating element

My first question here is how should this all be connected from the generator? Does the single wire from the generator connect to one of the wires on the front handle and then the other front handle wire connects to possibly the blue wire (green in image) connected to the right side rear handle heater with the short black wire leading from the switch connected to ground? Is there another wire, harness or other part that I am missing?

Second question, the wire plugging into the generator wire, how is that routed through the saw body to get to the front handle or rear handle area (where ever it goes), is it just tucked out of the way of hot and moving parts or is there a specific route for it?

 

[hacskaroly]

Today I came across the service manual for the 272 and in it there was a diagram showing the wiring connections. Basically it is set up to run in series, from the generator to the front handle, from the front handle to the rear left handle, from the rear left handle to the rear right handle, from the rear right handle to the switch and the switch to ground (chassis).



Its pretty straight forward, between 8,500 and 10,000 rpm, the generator should put off about 20 VDC. When the switch is turned on, the heating elements will heat up. If at any point there is a component failure or break in the line, all components stop working.

Testing the different points in the diagram (A1/A2 - chassis, B, C, D, E) should help provide answers if the parts are working correctly or not.

• A1 and B - Connect Ohm meter, should get between 0.9 and 1.3 ohm, anything else the generator is faulty.
• B and C - Connect Ohm meter, should get between 3-4 ohm, anything higher, front handle heater is faulty.
• C and E - Connect Ohm meter, should get between 0.7 and 2.5 ohm, anything else whichever heat loop (right or left) that has the higher value is faulty.
• D and A2 - checking the switch, connect ohm meter, with the switch in the "0" position, ohm reading should be greater than 1000 ohm, with the switch in the "1" position, ohm reading should be 0.1 ohm at the highest.

As for my setup, if all of my components are working correctly, I can get the rear handle heaters working, just need to patch up the wiring coming off of the generator, connect it to the rear left heater, re-solder the rear right heater to the switch and then connect the switch to ground. At some point if I come across a front handle with a heating loop in it, I will be able to wire it into the system. Though I have not yet come across where to run the wiring, further cleaning of the chassis has revealed several holes where wires can be run through, I will have to test them out to see which route will work out the best for this.