Howdy all:

My son purchased a 1998 Sentra and the rear window defogger was not working.

Checked the 20 amp fuses; all good.

Did a continuity check of the defroster grid on the rear window and there was good continuity noted.

Pulled the switch from behind the counsel and noted when I clicked it it would not click in the open position the way the hazard light switch next to it did. Did a continuity check with it depressed and it checked out fine (light came on).

Reinstalled the switch, activated it and used a wedge to keep it depressed thinking it would close the circuit and activate the defroster....no joy.

Purchased another counsel switch off of e-bay, installed it and still no joy

Took the + lead off the defroster on the rear window, stuck the + end of my multi meter in it while placing the - lead from the meter to ground on the door jam with the meter set at 10amps DC with the car running... 0.000 noted.

At a loss as what to do next...any suggestions would be greatly appreciated. Note: I am not an electrician so pls reply using layman terms as much as possible...

Thx

 

Hi MM the following information may help for you............
There are 3 fuses that control the rear defogger, and 1 relay.
The fuses are 10 amp HEATER, 10 amp MIRROR-HEATER, under the dash.
The 30 amp DEF fuse is in the fuse box under the hood.
The relay is the DEFOGGER relay,which is on the back side of the fuse panel under the dash.

The rear passager panel the one that cover the side rear window there a relay connector in there that were the power to window go that defectif that gonna FIXYA.

Also, check for a loose wire on the defroster grid (on the back glass), this is the most common problem.

A common thing to fial on these- assumning the grid is ok,and wires are still attched to grid, is the rear def / antenna module.It is behind rt. rear quarter trim panel.The modules burn up, and also melt the connector. the module and connector would need to be replaced.