macafee2 Posted May 21, 2019 The TEB7AS relay used to operate trailer electrics has started screaming. Any idea why? what could be cause and fix could be? The trailer is not plugged in. Not had an issue before and its been there for a few months but was originally wired to an ignition live. Cant recall how long its been connected to a permanent live Do these burn out if wired to a permanent live? Instructions say connect to permanent live. macafee2 Quote Share this post Link to post Share on other sites
AlwynMike Posted May 22, 2019 Can you adjust the trigger voltage on your model? Quote Share this post Link to post Share on other sites
macafee2 Posted May 22, 2019 9 hours ago, AlwynMike said: Can you adjust the trigger voltage on your model? no idea. I think there is a screw in one corner but what is cause of the screaming? macafee2 Quote Share this post Link to post Share on other sites
xtrailman Posted May 22, 2019 For around £25 I would just change it. I had one for 5 years with no issues fitted to two cars. Quote Share this post Link to post Share on other sites
AlwynMike Posted May 22, 2019 51 minutes ago, macafee2 said: no idea. I think there is a screw in one corner but what is cause of the screaming? macafee2 I thought that your car voltage was just on the trigger point for the relay and it was chattering on and off rapidly. More thought was that there is a fair amount of hysteresis built in to stop that sort of thing. Tweak it to see if it stops - or replace! Quote Share this post Link to post Share on other sites
xtrailman Posted May 23, 2019 Its a bypass relay not a VSR, so no voltage trigger point adjustment. It used only for the road lights and indicators. Quote Share this post Link to post Share on other sites
AlwynMike Posted May 23, 2019 1 hour ago, xtrailman said: Its a bypass relay not a VSR, so no voltage trigger point adjustment. It used only for the road lights and indicators. Apologies for my lack of knowledge and assumption! Quote Share this post Link to post Share on other sites
Black Grouse Posted May 23, 2019 2 hours ago, xtrailman said: Its a bypass relay not a VSR, so no voltage trigger point adjustment. It used only for the road lights and indicators. Smart relays usually have a trigger voltage adjustment - to sense when the engine is charging - when it is, voltage is over 13.8v, when it's not it's below 12.8v Quote Share this post Link to post Share on other sites
xtrailman Posted May 23, 2019 2 hours ago, Black Grouse said: Smart relays usually have a trigger voltage adjustment - to sense when the engine is charging - when it is, voltage is over 13.8v, when it's not it's below 12.8v There was nothing to adjust on mine, all it needs is a live feed. Quote Share this post Link to post Share on other sites
Black Grouse Posted May 23, 2019 31 minutes ago, xtrailman said: There was nothing to adjust on mine, all it needs is a live feed. Some smart relays have the adjustment hidden under the label. Quote Share this post Link to post Share on other sites
xtrailman Posted May 23, 2019 2 hours ago, Black Grouse said: Some smart relays have the adjustment hidden under the label. TEB7AS is just a bypass relay no adjustment, but permanent live feed required. TEC3m is a VSR and does have a screw for voltage adjustment. Quote Share this post Link to post Share on other sites
macafee2 Posted May 23, 2019 On 22/05/2019 at 17:59, macafee2 said: no idea. I think there is a screw in one corner but what is cause of the screaming? macafee2 I was wrong, no screw macafee2 On 22/05/2019 at 18:14, xtrailman said: For around £25 I would just change it. I had one for 5 years with no issues fitted to two cars. why change it blind? If no one has any ideas what the cause and if I cannot find a reason, then change it it will be, I have a spare. I'll make my life easy, the soldered wires I'll cut and fit to a terminal block then the wires from the new relay can fit into the other side of the terminal block. The wires have been soldered into the cars harness as not fault was anticipated. macafee2 Quote Share this post Link to post Share on other sites
xtrailman Posted May 23, 2019 At £25 to change or nothing if you have a spare its the easiest option just to replace it. No professional is about to take it apart to find the fault, although in your case I would just to see if anything obvious is to be seen . Assuming the spare works ok. Only thing I can think of would be the indicator buzzer circuit is faulty. Quote Share this post Link to post Share on other sites
macafee2 Posted May 24, 2019 Took it apart and can see corrosion so fitted the spare. Seems ok but I need to hook up a trailer to test under load. macafee2 Quote Share this post Link to post Share on other sites
xtrailman Posted May 25, 2019 Sounds promising, thanks for the feedback. Quote Share this post Link to post Share on other sites
