Toyota Prius Forum banner

1 - 9 of 9 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I own a 2002 Prius with DRL's and do not regret the purchase of the option. However, there are times when you don't want any lights on. I have installed a DRL override circuit on my Prius last weekend and it works great. The circuit consists of the addition of a 1000uf 25V capacitor, a small rectifier diode, a pushbutton switch, and a DPDT relay from Radio Shack. All the parts cost about $10.

Installation involves unbolting the passenger side underhood fuse block and turning it upside down. A wire (the one from the DRL relay to the ground side of the headlamps) must be cut. The relay contacts are placed in series with the cut lead. A pushbutton switch mounted at the base of the dash requires a small lead to be routed to it from the circuit (capacitor, diode, and relay) mounted under the hood.

Once the Prius is started, and the parking brake released, the DRL's come on as always. When the pushbutton switch is depressed the DRL's are shut off. If you turn on the headlights, the circuit is reset and when the headlights are shut off the DRLs come back on. Using the headlight switch for "flash to pass" does not reset the circuit to turn off the DRL's unless you hold the headlight stalk on for about two seconds. The nice thing about the mech is that it always reverts back to DRLs each time you start the vehicle--so you don't forget. The mod results in no current drain on the vehicle 12 volt battery when the Prius is "off".

Installation took me a good 3 hours (obviously it was the 1st time--but I am an electrical engineer) and it is not for those who are not comfortable in wiring simple electrical components, splicing and routing wires.

If there is interest I can post the circuit and some pics on the installation. This is the way that DRL's should have been wired in the first place.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #2
Richard, I would be very interested in info on the circuit and info on installation. I initiated a post on the Prius side, (I should have put it on the mechanical side), and would love an installation similar to yours. I would prefer to also have the DRLs come on automatically and have to shut them off. I think your idea is a great one!
Thanks for the post,
Tom Thomson
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
I notice that when my parking brake is engaged the driving lights STILL stay on. Is there something I am not doing. Of course there is nothing about these in the manual.

Thanks

[%sig%]
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #4
Actually what I would like to see is a photo electric cell that automatically turns on all the lights when it starts getting dark. Like my other cars do.

[%sig%]
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #5
Attached is an Adobe PDF with the schematic and discription of the DRL shutoff circuit mod for the Prius. Hopefully you will find the information useful.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #6
Dick, thanks for posting the info and the excellent directions. I had to order a capacitor from Radio Shack (they had nothing close in stock). The capacitor costs $.72, but the charge is $2.50 to ship. I have the relay, diode, and an AC pushbutton switch (they didn't have a DC switch in stock). I'm not great at reading electrical schematics, so I may have a question as to how to connect the electrical circuit with the capacitor, relay, and diode. I can tell it took a bit of time to write this up, so once again I really appreciate the info. This is exactly the way I want my DRLs to work.
Tom Thomson
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #7
I'M WITH TC I WOULD LIKE TO HAVE AUTO ON FOR LIGHTS, BUT ALSO BE ABLE TO TURN ON MANUALLY. AUTO SHUT OFF WOULD BE A NICE FEATURE WHEN ACC TURNED OFF.

I'M A SOCIAL WORKER WHO LIKES ELECTRICAL PROJECTS AS A HOBBY. THANKS FOR THE INFO .
STEVE B
CROSSVILLE TN.
02 MOON BLUE
GOT IT 04/26/02
1100MILES
 

·
Registered
Joined
·
15 Posts
Prius DRL Override Circuit

To this post I have attached the PDF file containing the info required to modify the Prius DRL circuit. This is the original info that I published in May of this year, but has apparently been "lost" from the board. I have received several E-mails requesting the info so it's back here as an attachment.
 
1 - 9 of 9 Posts
Top