Dodge Repair/'03 Ram: horn stuck "on"
QUESTION: I have a 2003 Dodge Ram 1500, and my case is every time the temperature drops below 32 degrees the horn will sound and stay stock till I disconnect the positive terminal, and this seems to happen around 3:00 am wend the temperature drops the lowest. Can you give me some troubleshooting so I can take care of this problem?
ANSWER: Hi Derrek,
The most likely cause is a faulty horn relay which would be located in the power box in the engine compartment. So look into that box to find that relay and if there is another one with the same part number that is not essential for a test purpose/driving at this moment then remove the old horn relay and try the substitute. If that stops the problem then buy a new relay. Otherwise the horn switch at the steering wheel is the next item to consider but it is more difficult/costly to replace and less likely the reason.
Revision in response to your evaluation:
The '04* horn wiring diagrams show there to be a relay in the power box but the specific drawing of the relays in that box does not list a horn relay. However there are several unused relay sockets shown and I would believe that one of those sockets has the relay. Specifically at the end of the box closest to the fender there are supposed to be two spare relay sockets but if you have only one then a relay on either side of the open socket is probably the horn relay. You can cut off the horn by removing fuse 45 until you find the horn relay in that box. You could also try removing the relays in the box one at a time until the horn shuts off. Let me know where you find it to be, please, as this is a 'mystery' to me also.
*I don't have the '03 or '05 diagrams, but '06 shows the power box to be different from that in '04. So I do believe the '04 box is just like your '03 as they don't change the box every couple of years.
---------- FOLLOW-UP ----------
QUESTION: I am looking for a horn relay diagram for a 2003 dodge ram 1500
Please let me know if you find a layout for the relays in the power box in the '03 engine compartment. I have the '04 wiring diagram that shows the use of the relay and the fuse that powers it (#45), but as I said the drawing of the box doesn't show the relay, but there are several "spare" slots, one of which is the relay no doubt. And a plug on the bottom of the power box shows the dark green/orange wire coming from the relay via pin 14 of the 26-pin plug on the end of the box and going to the horns but again, no way to ID which relay that wire is attached to other than it is probably a relay in the end of the box near the fender.
Another way to find the relay is when the horn is stuck "on" try pulling the relays out of the box until the horn stops. Or have a helper sound the horn while you touch each relay until you feel the one that clicks.
If you would like to see the wiring diagram itself let me know your email address and I'll copy it and attach it to an email. Don't use the @ symbol but instead us "at" or the address will be erased from your follow-up question.