Patrick Brady Posted January 9, 2020 Report Share Posted January 9, 2020 I have fitted a high torque starter to my 4, negative earth. The cable from battery to solenoid from Moss was too short, so I have fitted a 25mm2 cable from Vehicle Wiring Products, which I gather is for 170 amps. I now see that the Moss catalogue, page 85, in notes on the Engine Earth Strap, says current can be up to 200 amps. Was this for the original starter? The WOSP advert, page A50, shows 1.4kW for the high torque, which would require about 120 amps. I think this must be right. Can anyone confirm this please. Quote Link to post Share on other sites
RogerH Posted January 9, 2020 Report Share Posted January 9, 2020 Hi Pat, The HT starter does take less current. It gets its torque through gears. So the initial current surge is much less then the original motor. Take care how you wire it in. You have options. I find it easier to go through the existing solenoid. Roger Quote Link to post Share on other sites
RobH Posted January 9, 2020 Report Share Posted January 9, 2020 25mmsq cable is perfectly adequate. The published cable ratings are for long runs of cable as part of distribution systems, to keep within reasonable temperature limits. Your couple of feet of starter cable in free air will be fine. A metre of it will have a resistance of less than 1milliOhm which even at 200 Amps gives a voltage drop of <200mV and a power dissipation of <40 watts which for the short duration of cranking won't even make it warm. Quote Link to post Share on other sites
Patrick Brady Posted January 9, 2020 Author Report Share Posted January 9, 2020 Many thanks for two very quick responses: RobH, for a very technical reply which is reassuring; RogerH, for a practical reply. I didn't know about the options - have wired to the solenoid, which has worked. Cheers, Pat. Quote Link to post Share on other sites
ianc Posted January 10, 2020 Report Share Posted January 10, 2020 Like Roger, I have wired my high-torque starter motor via the solenoid because I have a solenoid with a pushbutton, so can operate the motor whilst standing alongside the open bonnet. Helpful when undertaking compression testing as one can hold the accelerator wide open at the same time and watch the pressure rising (I have a tester which works like an old-fashioned tyre pressure gauge). Ian Cornish Quote Link to post Share on other sites
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