Controller overheat ?

[TRPetr]

I have a 04 TXT in the process of rebuilding. Planning to upgrade battery cable to 2ga, and I plan to keep the original stock Curtis controller and solenloid, at least for the time being. In removing the controller and heatsink, which came out in one piece (the splash panel rusted through, so it was easier to pull the whole assembly out), I eventually snapped the last bolt holding the controller to the heat sink. The heat sink is covered in a white residue, looks like some sort of galvanic corrosion.

My question is regarding the heat transfer pad between the controller and the heat sink. I 'm afraid I'll damage it in removing the corrosion residue, and I don't know if the controller will overheat with upgraded battery cables and the heat transfer pad missing.

I'm spending enough time and dollars just getting the frame restored, new shocks and springs, rear seat kit, windscreen, etc. I'd like to keep the F/R switch, controller and solenoid stock for a little while, and get this cart on the road. That will make my banker happy enough that I can then justify the remaining electrical upgrades.

[Briboy]

It may be that someone else had removed it once before and added Heat Sink Compound.
Or came from the factory with it (I will leave that for the experts).
Anytime you encounter a type of heat sink there are pads that are a lot less messy and then there is the compound (Old School) that you smear in between the sink and the chip or board that creates the heat. It helps transfer the heat to the sink for dissipation. You will know it is heat sink compound if it gets on your hands it does not come off easy.
A picture would help us on the other side determine if my info is helpful.

[JohnnieB]

The thermal pad is not reusable, or at least not as effective when reused.

Replace it with thermal grease. Doesn't have to be the expensive stuff used for CPU heat-sinks. IIRC, the stuff I used was about $10/Oz.

EZGO mounted the pad crooked and it had wrinkles in it, so the only thing good about it was the adhesive. I had to use a wire brush to remove it.

[TRPetr]

This is what it looks like. Based upon the comments, I should scrape off the thermal pad and use thermal grease. Any idea on whether or not the controller might overheat with the wire upgrades?

[JohnnieB]

Originally Posted by TRPetr

This is what it looks like. Based upon the comments, I should scrape off the thermal pad and use thermal grease. Any idea on whether or not the controller might overheat with the wire upgrades?

My first upgrade was installing 2Ga cables and I didn't notice the controller running warmer, but I didn't remove the original controller until I replaced it, so the heat pad contact (what there was of it) wasn't disrupted.

Technically, the thicker cables will allow the motor to draw a few more amps through the controller, but the voltage drop across the controller is only about 0.1V/100A, so there won't be much of an increase in heat.

The problem you have in addition to the the heat pad not being reusable is the broken mounting bolt for the bottom of the controller. If you cannot get it out, you can drill holes on either side of the single hole on the controllers bottom flange and use some self taping bolts to secure the bottom of the controller.