Hi, I am hoping someone can help me out I have a 2000 Blazer LS 4 Door 4.3V6 and it has a 4 pin flasher/turn signal realy and I would like to replace it with a 3 pin adjustable speed relay and just wanted to know if this is possible at all as I see the pins are in the same place but with just one missing....I do understand that some modification would have to be done is this is at all possible.....

This is the relay I have


and this is the one I would like to use

Thanks in advanced to all for the info and help...it is much appreciated

 

In the stock configuration, there are two separate power sources to the flasher, one from the TURN fuse (#10 - 20A - IP fuse block) and one from the HAZ LP fuse (20A - underhood fuse block). These could be combined, but you may need to put a diode on the TURN fuse input at the flasher to eliminate feedback through the TURN fuse circuit. The TURN fuse circuit is only powered in RUN & START whereas the HAZ LP fuse is powered at all times.

What I cannot tell from the diagrams is if the circuit for both the HAZ LP fuse & TURN fuse are active at the same time ever or if when the hazards are on, it (the multifunction switch) disconnects the circuit to the TURN fuse. You could test this by testing for power at the flasher. Cavity A1 is from the TURN fuse and should have power in RUN & START (I think only when the turns are also active), B1 is from the HAZ LP fuse and should have +12V at all times (I think only when the hazards are on), B2 is the ground, and C1 is the output back to the multifunction switch. If A1 has power with the engine running and the hazard switch activated, then you will need a diode or another relay to break the connection to the TURN fuse circuit when the hazards are active.

Alternatively, you could test continuity on the flasher itself. If the pins corresponding to A1 & B1 show continuity, then the multifunction switch must connect/disconnect the appropriate circuits to prohibit back feeding. Looking at the picture you posted of the 4-pin flasher module pin A1 would be the one on the left in the row of 3 while B1 is the middle pin in the row of 3. If these two pins show as open, then you must do the testing on the wiring in the truck as described above.

 

@swartlkk

Thank you for that but that seems like a lot of work and I don't want to touch the wrong place and short anything out so, I think I will just leave it flashing faster like it is now....Thanks

 

Flashing faster? As in hyper flashing because you have a burnt out bulb or changed to LED'S? If that's the case you can replace the burnt oUT bulb, DE-solder the lamp detection leg in the relay, or replace the relay with a ep29 led relay.