viper 5904 rear defrost not latching

Salutations all,

The Viper 5904 ....H2/3 (2nd harness, wire #3 (blue/white) is dedicated (-) 200 mA ground for the Rear Defrost.

I tried 3 times to program this output to "latch/ign" (feature programming menu 3, item 11, option 2). So far, my multimeter is still reading 650 mA "pulsed" for 1/2 to 1 second, 10 seconds after remote start. This is what I think is still the factory setting (menu 3, item 11, option 1).

I wired H2/3 to (Bosch 30A relay) terminal 86. I hardwired 87 & 85 straight to battery (inline 30A fuse at battery), and 30 hardwired straight to defrost.

If my programming did what I think it is supposed to do, H2/3 should have a constant 650 mA beginning 10 seconds aftter remote start, and hold until remote start times out, or shut off.

Please help.... I'm completely lost now.

Your relay wiring should be;
H2/3 to 85
86 and 87 to 12v+ constant fused at 30 amp
Cut the wire
Switch side to 87a
Rear window side to 30.
Diode across 85 and 86, 1N4004, band to 86. MANDATORY.
What vehicle?
N.B. to effect programming, door must be opened or green wire at H2/6 grounded.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I believe the Bosch 20/30A automotive SPDT Relay has the proper diode, but I thought in this application, 85 and 86 are reversible.

I actually have 2 relays (I also installed a trunk pop and motor). The relays are plugged into a twin base with a common 87 and 85 (why I swapped 85 for +12v side. Not sure what wire I need to cut, or why I am wiring anything to 87a for this?

The trunk pop works great. Both relays test OK.

While programming, I opened the door, turned the ignition on, then off (and pulled the key out completely before holding the control center button for 3 chirps, then 11 presses, then one more..hold and press "unlock" ....what am I missing?

H2/3 shows 650 mA for 1/2 second. This is a pulsed output, not latched. Am I wrong in thinking that I should see 650 mA for the 10 minute duration of remote start?

BTW - This is the wire that only activates when below 55 deg F (which it is)

My vehicle is a plain Jane 92 Camry automatic. The rest of the install (remote start, sensors etc...) worked fine on the first try.

You were right to make the point about the relay, no Bosch/Tycho don't "do" relays with built in diodes as standard.
86 by convention, i.e. that's how the car and the better alarm-R/S manufacturers do it.
The only important part is the band side of the diode to the (+) side of the coil.
Any way of utilising an aux to latch on with remote start?
Then relay that to feed the "hot" wire to the rear window.
Aux to 85
power to 87 and 86
cut "hot" wire and switch side to 87a
output from 30.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I figured out my problem was with programming the 5904. I wired the relays fine.

I was right to assume menu 3, item 11, option 2 did not "take"
It was activating for 1/2 second pulse rather than latch.

The 5904 communicates back to you with 11 chirps to "confirm" that this is the area you have "chosen". I selected option 2 during this sequence rather than wait fully for all 11 chirps to complete.
Make certain to wait patiently for all chirps to complete, or you will fail to re-program as I did. Don't wait too long either, or it will exit automatically. Timing is everything with this part.

Good luck,

Chris