using relays in place of the headlight motor control module (Page 4/4) Dukesterpro MAR 04, 03:04 PM So as a the only current designer of a replacment for the GM gen 2 module, as well as a easy conversion kit for Gen 1 Cars. FOR THE LOVE OF GOD, PLEASE DO NOT USE RELAYS AND TIMERS TO RUN HEADLIGHTS. That is of course if you like fires or burnt out motors. It is absolutely critical that your headlights are able to detect blockages and stop points like my module. https://www.youtube.com/watch?v=7oSIKKfNKjc If you want more reasons beyond what these fine gentlemen have already said. We can happily go over my 600 hours of testing for my capstone project theogre MAR 04, 07:49 PM Also Relays etc Specs printed on them & in data sheets are Resistive Loads mainly for AC Volts or if includes DC will have much lower volts. Read the sheets more then 1 paragraph & real sheet cover Inductive Loads like Motors & most are now rated for 1/4 to 1/3. Other Sheets don't say anything because of other issues like copy part made in China & other 3rd world countries. So most "users" don't bother w/ that including some self claim experts & wonder why keeps frying Relays, Switches etc. Example: Many here have Songle Relays from "Arduino" projects w/ 10a printed on them but never read the data sheet from Elegoo etc saying same thing that motor can only draw ~ 1/3 of amps printed on them. That ignoring back EMF that often burns the contacts shutting Off power to the motor. Leviton, Omron & others old brands nearly always have same "issue" to derate the contacts for all Inductive loads. Like the "wall switch" the runs most garbage disposers in home that often needs replacing every few years. The relay for top post, if made to OE car makers spec, is made to handle ~ 10a max Inductive to run F-pump, heater blower, etc that pulls typically 5-8a. Big problem is many new parts are cheaply made to total counterfeit and won't last long or weld the contacts causing big problems. And Fuses etc may not Blow/Trip before starting a fire because other parts have enough resistance they "see" no problem. Yes is a Relay in Gen2 Modules but does Not switch power, only set direction. The MOSFET are the switches rated 10a or more. Even then the 5a relay contacts still wear or burn. While that relay looks standard Omron part it isn't. Is a "custom" part for GM w/ high contact rating. IOW you can't buy exact same relay @ mouser etc. Mickey_Moose MAR 05, 02:03 PM quote Originally posted by theogre: While that relay looks standard Omron part it isn't. Is a "custom" part for GM w/ high contact rating. IOW you can't buy exact same relay @ mouser etc. ^^^ this ^^^ The actual part number for the relay in the module is: OMRON MY4-02-GM Note the final 2 letters, you can buy a OMRON MY4-02 anyplace, however as theogre said it is not the same part unless it includes the -GM at the end. I am not going to assume that the GM is for General Motors, but it could very well be and it was designed for GM specs. theogre MAR 06, 11:27 AM Omron & others did & still makes "custom" jobs for any buyer w/ big pockets ordering Thousands of parts minimum. I have little doubt number ends w/ GM is for GM + When you read spec on side of the Omron "GM" say 5a but "02" is only 3a. Is likes the "change" between is so small that near no-one can see a diff just by looking or even measuring. Even just change exact contact metal matters & can't easily tell looking. (Like Stant made OE caps for GM Ford etc. w/ relabel for them. Sometime could still find just S logo on "Ford" etc parts many years ago.) ⚠️ Even w/o switching power itself... motor pulls ~ 4a when everything works right. That alone will "overload" the contact section of 02 before you add other issues. Worse, "GM" parts designers only use simple resistor as "snubber" to protect the contacts. That helps but not same as better methods to control back EMF etc even at time was made. Likely design choice to fit Been Counters demands... (some page is wiring in the module but no time to link right now.) Is part of why cave gen2 page say don't a good plan to fix most problems w/ the module.