I replaced the old round relays as they were older than me. Problem is now they do not work. I got some three plug horn relays from Napa. ground lead goes to the horn/reverse light switch, hot wire goes to the power lead, and then the power out to the horn/reverse lights, just like the wiring diagram...problem is they dont work and all the wiring has been double checked.
what am I missing here? It is very frustrating.
Thanks in advance.

-Erik

Ron sounds a little frustrated himself, so I'll chime in. Basically you need to understand the relays better. Use a multimeter to make sure you understand when the relay is open and when it is closed. i do this by using some leads from the battery, I attach leads where I think they should be, mimic the action of the switch (in the case of the horn this is a switch that grounds) and see if I am getting voltage where I want it. I then use this information to install the relay. It sounds like you you think you wired it right, so my explanation is that you have the plug i.d. mixed up, or if all else fails you have bought defective relays (I doubt it, I use Ford type relays as they are cheap and seem to last). Finally, I still have the old round relays in my 220 and have never had a problem with them, this begs the old adage "if it ain't broke..."
Check out the link that Ron gave you, it is well laid and pretty much explains as much, if not more, than I know about electrics, and I can wire/diagnose anything on a 120 and have been known to successfully take on much more complex vehicles. It's a bit steep a first but the learning curve in auto electrics flattens out fairly quickly, a few Eureka! moments and it all becomes old hat.

Thanks Patrick and Ron,
it turns out I am not going completely insane (to date anyway)The relays I got only had numbers on the leads, and no references except the scrap note from the kid at the counter about which did what...turns out they were the wrong relay :)
so i'll try again after work and see what progress comes. This car did not have a horn relay and the reverse relay was original and looking rough, so that is why i replaced them Patrick.

Erik;

...in that case, it sound like you need to triple check the wiring! Besides how can you think that one of us can possibly help you figure out what's wrong with what little info you gave!

What, specifically, did you find when you "double checked" the wiring? Did you try the relays out of the car? Based on what did you work them into your harness?

What are you missing? Dunno, but the new relays need power and ground across the coil to work...I suggest you get unfrustrated, adjust you additude, and check some more...it ain't rocketscience.

This MIGHT help: http://www.intelab.com/swem/an_automotive_electrical_primer.htm

Good Hunting!