Wizard Imports Limited
TEB7A-24 7 Way Bypass Relay
This 7 way bypass relay may be used on 24v negative earth vehicles which require a bypass relay to be fitted for circuit protection or to avoid confusing the bulb failure warning systems when towing a 12v trailer or caravan.
7 way bypass relay with 7 terminal outputs arranged in 12N sequence including reverse.
Statutory sensing of trailer flasher function without the normal voltage drop avoiding potential dimming of flasher bulbs.
All circuits fully snubbed for EMC protection.
Normal rules of competency apply to anyone fitting this relay to a vehicle.
It should be fitted to negative earth vehicles only.
Great care should be taken if the relay is fitted to a vehicle having multiplexed circuitry, and no attempt should be made to interrupt or interfere with the BUS, the ESUs or the power cable of a multiplexed system. Power sources should be taken from the main fuse box or battery and signal sources from the regular 24v system directly feeding the various rear road lamps.
Fit 12N socket and cable according to instructions supplied with the socket kit.
Fit 12S socket and cable where required (i.e. if reverse light is to be attached) according to instructions supplied with 12S socket.
Route 28/0.3 cable (2.0 sq mm) from car battery centre post (i.e. 12v tapping) to boot or fuse box, fitting an inline 15a blade type fuseholder, but removing the fuse at this stage. Alternatively a 24v – 12v Switch Mode Converter may be used to generate the 12v output to the trailer.
Offer up the relay to the above cable clusters and make secure connections through the terminal blocks on the relay according to the chart Below.
Connection to Relay
28/0.3 (2.0 Sq mm) cable from car battery 12v centre post
Do not make any connection if relays’ buzzer is to be used.
Otherwise connect to panel lamp on console via light signal wire and then from the panel lamp to earth.
12N Cable. Yellow Lead
“ “ Blue Lead
“ “ Green lead
“ “ Brown lead
“ “ Red Lead
“ “ Black Lead
12S Cable. Yellow Lead
Using scotch locks, solder joints or similar, attach the various leads coming from the underside of the relay to the car loom, teeing in at a point close to the car lamp circuit that is being sampled and avoiding any multiplex wiring or other devices.
Signal Wire Connection to Vehicle Loom
Near Side Flasher
Off Side Flasher
Off Side Tail Lamp
Near Side Tail Lamp
Secure firmly to vehicle chassis via ring terminal
Secure the relay to the harness or similar preferably using a tywrap,
Insert the inline fuse and test. If a test board is used, it should have 21w bulbs on the flasher circuits as the buzzer only works under load conditions.