I have a 2003 F250.

I have a set of Lightforce Striker 170s already installed in my truck.

They are wired to a 30 amp relay which gets power from my aux fuse block. The power wire is ran from the fuse block to terminal 87 on the relay.

I have this pair of lights wired to a three way toggle switch in the cab. ON - OFF - ON. Up means the lights come on any time the key is on. Middle means they are shut off, and the bottom position means they turn on when my high beams are activated.

Worked great.


I wanted the new set of HIDs to be controlled by this same three way switch so yesterday I installed a pair of Lightforce Blitz 240 HIDs. I installed the ballasts and grounded them directly to my battery. The power wire I ran to my existing relay and hooked the power to the 87A terminal of the relay.

I reinstalled the fuse in my aux fuse block and the new HID lights came on 100% of the time, whether key off or key on.

I did some research on this type of relay and learned that 87A will have constant power when switched off which I guess explains why the new lights came on immediately.

OK, no big deal right? So I went to Napa today and bought a new relay with DUAL 87 terminals (no 87A). So I installed that today. Put the fuse back in, providing power to the relay.

Now none of the lights come on, not even the old set I had previously installed. My high beams also no longer come on. Low beams work fine but when I turn the high beams on the headlights shut completely off.

I checked the fuses and my factory high beam fuse is blown and the 3 amp fuse in the cab is blown that powers the toggle switch to turn on the relay. OK so this explains why the lights aren't turning on but why are these fuses blowing?

With the new dual 87 terminal relay installed I replaced the fuses in the cab, flipped on the toggle switch and the same fuses blew again. The 30 amp fuse that provides power to the relay from my aux fuse block does not blow though.

What am I missing here? It seemed like it should have been a straight forward install. I'm real confused especially as to why the other fuses are blowing when none of that wiring changed. All I have theoretically done is change relays and connect another wire to the second 87 power terminal on it.

My relays are wired into the plastic blocks so all I have to do is unplug them and plug them back in, so none of that got changed around either.

 

Lights (Load) should be on #87
Power (Feed) Should be on #30
#85 (+) & #86 (-) are the Coil Switch (What activates the Relay)
#87A Is "Hot" when the relay is at rest. Off when the Relay is energized.

Hope this helps.

Tom