Relay on firewall - location?

[davepl]

I cannot figure out the location of the 3-prong, 1-bolt relay that goes on the firewall. Could be for the TH400 or emissions or trailer, I have no idea at the moment, but could really use a photo of the proper location!

Thanks,
Dave

[hugger6933]

Dave what have you got what are you doing ?I have a 70 that has a relay thing on the side of the heater case between the heater case and the dist mounted to the firewall. Is that what you seek? I also have a relay mounted over by the steering column between the column and the inner fender. Is that Closer to what your looking for? The 70 I am work in on in my shop right now is a no air 3 oot wit ha V-8. I have a68 original big block now small block with T400 and air out back I can look at if that will help. But on th 68, the T 400 kick sw is under the dash on the throttle pedal I think.

[Tom Vogel]

[QUOTE= But on th 68, the T 400 kick sw is under the dash on the throttle pedal I think.[/QUOTE]

On my 69 it was on the intake manifold right under the throttle linkage. The horn relay goes next to the steering column I believe, it has one bolt head screw.

[davepl]

I think I have 3 relays; there's one under the aux battery tray that I presume is the horn relay. Or it might be for the camper wiring.

There's another on the heater/ac box.

There's a third that came from or near the firewall; it could be related to kickdown, but it might also be for the trailer wiring.

So, it's the one on the driver's side as Tom describes, which is probably the horn relay as he says. Problem is I have a dozen holes and none seem to match up with the single bolt and the tab on the relay bracket.

Also, the assembly manual shows it on the fender, which isn't right at all.

So, if anyone has a photo, or can take one, please share! In the meantime, here's a map of the other holes in case it's handy for anyone:

[davepl]

Hold on, maybe I did take a picture! The baggie I put it in I wrote "Relay on firewall", but it probably is this one on the INSIDE of the firewall.

So, I think I've solved the location, but still curious as to what it is. Given the green wire, horn?

BTW, unrelated but I had to make an adapter yesterday because the replacement harnesses don't account for the aux battery tray which places the horns in different locations (both on same side).

[Bigdav160]

Yes, horn relay.

[WIDESIDE72]

Originally Posted by davepl

Hold on, maybe I did take a picture! The baggie I put it in I wrote "Relay on firewall", but it probably is this one on the INSIDE of the firewall.

So, I think I've solved the location, but still curious as to what it is. Given the green wire, horn?

BTW, unrelated but I had to make an adapter yesterday because the replacement harnesses don't account for the aux battery tray which places the horns in different locations (both on same side).

All trucks with dual horns have them mounted on the driver side. Trucks with one horn mount the horn on the raised ledge nearest the radiator. Trucks with a second horn mounted it toward the outside of the radiator support and used a jumper harness about a foot long to power the second horn. IIRC trucks with one horn used a low note and the high note was added when equipped with dual horns.

[WIDESIDE72]

He horn relay is mounted directly anove the fuse panel inside rhe cab and has red green and black wires on my 72, with a pigtail about 6" long.