# Alltrax SPM failed while normal driving



## eman.cardona (Apr 20, 2011)

I have been using alltrax spm for the past two years. Yesterday I was driving my normal trip from work to home (only 1.5 miles). During driving I heard a blow noise (it could be the noise of the contactor went off) and I lost power. No supply, everything gone.. I pulled off the road whilst the car was still moving by inertia and opened the motor compartment. I could not find anything abnormal.. Everything was cold even the motor. I had to tow the car to my garage.

I tried to connect a 12V auxiliary battery and the instruments came on (I usually use only the sevcon DC DC without 12v battery). Still the contactor was not turning on and I had a red blinking light on my controller when tried to switch on..
I hooked up the laptop and connected the controller via usb. It is giving me error flags 'Shut down' 'precharge fail' and 'low battery'.

Controller is blinking 1 green and 6 red.

Checked basic connections fuses etc and even tried to replace the pre charge resistor. All in vain.

Can someone help? What could the problem be?

Thanking you in advance for your support.

Regards,

Eman


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## redcelt007 (Oct 2, 2008)

Which model spm controller do you have? If it is the type that has a connector to power contactors? Have you checked the output there?


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## Yabert (Feb 7, 2010)

redcelt007 said:


> Which model spm controller do you have?


From EValbum: SPM72400

Hi Eman
I hope the Alltrax compagnie will be able to help you.
Good luck


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## eman.cardona (Apr 20, 2011)

redcelt007 said:


> Which model spm controller do you have? If it is the type that has a connector to power contactors? Have you checked the output there?


Hello guys, model is spm72400. Yes it has the coil driver output from controller to contactor. During fault condition, supply at the pins is only about 7volts. I will try to check the supply exactly when I turn the key. What should the voltage be? 12v or 72v? I will try to apply direct supply and see what happens...


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## Qer (May 7, 2008)

I googled on spm72400 error codes and found:

http://www.alltraxinc.com/files/DOC113-001-D_OP-SPM-SPB-OPERATORS-MANUAL.pdf

From there, page 28:

"1 Green and 6 Red LED Flash = Pre-charge Failure"

Since it seems that precharge for this controller means "Keep the circuit always powered" it could either be your resistor being burned off or the caps in the controller blew.

Easiest is probably to contact Alltrax and ask them for advice.

http://www.alltraxinc.com/contactus.html


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## redcelt007 (Oct 2, 2008)

You should get the same voltage that your battery pack is delivering to the controller. Check the output while the throttle is depressed while in neutral gear. If you are running 72 volts, that's what you should see. Is the coil on the contactor rated for your voltage? Also, how are you pre-charching the capacitors?


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