stevec205gti 0 Posted November 20, 2006 Yet another ignition amp question........ Does the backplate/back of the amp act as just a thermal connection to dissipate heat, or a thermal and electrical connection to ground? I've spent over an hour searching through old posts and there's no definates......yet!!!! (In case you haven't guessed my car's still stranded onthe driveway!) Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted November 20, 2006 Does the backplate/back of the amp act as just a thermal connection to dissipate heat, or a thermal and electrical connection to ground? Not a great help but possibly both an earth & heat dissipater. IIRC on the inner wing mounted coils the aluminium plate should have an earth wire running from it to the battery negative. There is an earth wire on the plug which afaik should earth through the main loom earth stud on the gearbox. If you suspect this, remove the rubber boot from the back of the plug & run a temporary wire from there to a suitable earth point & see if you have a spark. (assuming thats whats missing). Graham. Share this post Link to post Share on other sites
Anthony 1,003 Posted November 20, 2006 As far as I know the ignition amp doesn't need an earth on that plate, and it is purely there as a heatsink. Certainly I've just plugged ignition amps in without grounding them before to test them and the car has started fine. As Graham said above though, the main body earth does connect to the ignition amp plate (on cars where it's on the passenger side anyhow). Share this post Link to post Share on other sites
stevec205gti 0 Posted November 20, 2006 I've got a good earth from the plate to the battery (0.3 ohms) but was intrigued about whether wopping on too much heatsink compound was having an adverse effect on the amp's running Share this post Link to post Share on other sites
