Bizarre front/rear heater issue

[Rangeroad]

Can't figure this one out. Both my front and rear heater/blower stopped working. Figured it was the fuse and be an easy fix. All fuses in relay box and fuse panel on driver's side are fine. I read in a previous thread that there are fuses behind the glove box. I've taken the box off but can't find any fuses back there ('97 2.7l model), not sure if it relates to my model.

I had passengers in the back seat prior to this happening and I had heat running in front and rear. Both were working excellent. Then 2 days ago I turned on the heat in the morning and have nothing. No motor at all.

One thing I haven't checked are the relays. However, to have both heaters go at the same time is just too weird.

Any advice appreciated, thanks.

 

[Whitson Metalworks]

Check the relays and check the switch too, on a side note...heat?? It's already hit the 90's here in Fla lol

 

[smallfry]

Theres a relay and a fuse under the passenger seat.

Remove the passenger seat and pull back the carpet both of those items are on top of the housing for the rear heater.

 

[Rangeroad]

Ha, yes well its still chilly in the mornings and evenings up here in Canada!

Will a 12v. multimeter work for checking the relay points in the box? I don't think (2) switches could possibly go at the same time, unless the front switch is in tandem with the rear heater?

Thanks Smallfry, will check under seat.

 

[Rangeroad]

Fixed! Heater relay in engine bay box was the culprit.

Electrical question: I thought fuses were supposed to blow before relays? Anyone know the reasoning for when/why relays go bad?

Checked and troubleshot the rear heater blower when seat was out. Seemed in good shape.