You should have the round 2 prong circut breaker for the turn signal. The 4 way flasher uses another circut breaker just like the one for the turn signal. It is located on the under side of the in cab fuse box. If the 4 way flasher works and the turn signals don't, the turn circut breaker is probably bad.
On the starting fluid, if the glow plugs are disabled it is ok to use sparingly. If just one gp is working, it is not a good idea to use it. If you are going to use starting fluid, unhook the glowplug relay. That way the glows are totaly out of the picture.

 

The FLAPS dude is wrong (imagine that!). There is a FLASHER (not a relay, not a breaker, but a FLASHER) for the directionals and a separate flasher for the emergencies. One is facing you in the interior fuse box and one is on the side of the fuse box you can't see. I forget which is which, but by removing the visible one, it'll be easy enough to figure out.

That #1 fuse under the hood probably energizes more circuits in the cab than just the radio. Check your owner's manual; I don't have one at hand. It depends on whether that fuse is for the switched power or the always-on power for the radio. If it's for the always-on power, it's a common thing with aftermarket radios. Factory radios are usually wired so the main power draw is from the switched circuit, and the always-on circuit only provides a trickle of power for the clock and preset memory. Aftermarket radios "flip" that; they draw the majority of the power (for amplification, etc) from the always-on circuit, and use the switched power circuit just to trigger the on/off switch.

This is one case where the factory design actually makes more sense. The unfortunate consequence is that the always-on circuit can be overloaded by the amplifier power to the aftermarket radio. Usually this blows a fuse or melts a wire or connection, but it could be causing other issues. That's why, as suggested above, you should just decommission the radio (not by the fuse, but by the connector for the radio) for now.

Come to think of it, that #1 fuse might also be the always-on power for the emergencies.

 

Replaced the little $3 2 way flasher and the turn signal works now. The fuse is still out and the emergency flashers work. I went looking for loose wires and found an extra two relay box, that is supposed to be attached to the under the hood fuse box, dangling upside down just inside the firewall. I turned it back upright and it poured a little water out. That can't be good. It says relay 1 and relay 2 on top of the box but I can't find any reference to it in the owners manual. There are relays 1-5 in the under the hood box with #5 unused but this is actually a separate box with only two relays. Can anyone tell me what they are and any consequences of water in the connections? It was hanging upside down.

Anothter question. Can you tell me what I should see on a volt meter on the four posts of the glow plug controller. Seemed to have power to all four with the key off. Didn't know what I was looking, or hoping, for so I thought I'd ask before messing with it any more.

 

I believe the two relay box that you're referring to is the relays for the "towing package" or "camper package". They are the relays for the camper charge wire and the reverse lights in the 7 pin round "camper" plug.

As for the GPR, with the key off, there should be battery voltage to one of the large terminals and you'll probably see voltage at both of the small terminals. The way the relay works, one of the big terminals is battery power, the other is the wiring to the GP's. One of the small wires is battery voltage and the other (the ground side of the relay coil) is pulled to a ground by the PCM to turn the relay on. That's why you'll likely see voltage there with the key off. With the key on you should see battery voltage at both the big terminals and at one of the small terminals and the other small terminal should be a ground (until the PCM turns the GPR off). Also, make sure your meter is set to be reading DC voltage. You probably already know that, but some don't and you can usually get a reading of some kind using the A/C setting, but it won't be right.

 

I have that little extra relay box and was always wondering what it was. its immediately behind and slightly below the main engine compartment fuse box (not dangling) in my truck :-)

thanks FTE - learn something new every day!

EDIT: just went looking in the online manual and found a page in the electrical section that tells me that it exists, but doesn't help at all with what relay does what. anyone know of any better info on the trailer wiring? looks like the trailer wiring is shown in the wiring diagrams, but no reference to specific relays. also - some of the markings are quite cryptic. like big 'home plate' looking wire terminations that just say 'trailer power feed' and things like that. also, there's an interesting little wire to nowhere coming from the trailer power relay that says 'customer use.' what does that mean/where is that located, so that I can 'use' it.

...sorry for the hijack, but the reference to the extra relays go me going ;-)

 

What kinf of ohmmeter reading should I get on the non battery side?

Thanks for the help

 

You won't get an accurate ohm reading on the non-battery side (assuming you mean the other big terminal). The resistance of the glow plugs together will be too close to a dead short to give you an accurate reading. What you want to do is measure VOLTS at that terminal. Another thing you can do is to turn t he key on and measure volts between the two large terminals. If you get a reading greater than 1 volt you need a new relay.

 

Here is what I am finding in the workshop manual:

This is labeled "Trailer Tow"



And it says this:

Trailer Towing Package Wiring

Vehicles equipped with the trailer towing package have the following additions to support the trailer wiring:

• A set of relays in engine control sensor wiring (12A581) (Bronco) or engine compartment (14A346) (F-Series) and connector on the rear lamp wiring (14405), located in the rear bumper area.
• The trailer feed wiring (13A576) is supplied with the vehicle and installed at the time of pre-delivery.
• Vehicles are equipped with a wiring feed, located under the instrument panel, for a trailer brake control unit.

That's about all I've got.... but here is a link to the manual in case you want to look more for yourself. This information is under the "Electrical Distribution" section.


http://www.thedieselstop.com/faq/949...an/stjmain.htm

 

thanks nate - I found the writeup part in the manual, but not the wiring diagram.

interesting that the trailer turn signal lights are just straight wired to the vehicle turn signals, I guess. everything else gets a relay.

 

Originally Posted by OldWoodsDiesel
I have that little extra relay box and was always wondering what it was. its immediately behind and slightly below the main engine compartment fuse box (not dangling) in my truck :-)

I bet you can't dump water out of yours, tho.