Ok folks, I need your help. How can I test a relay to see if power is going through it? I know that power is going into it because I can hear it buzzing when energized. What I don't know is whether the power is making it out of the other side. It is a starter relay on my wifes van. It wouldn't start and I thought it was probably the battery. I changed that and still no start. I thought it must be the starter...took that off and had it tested...turned over great, but stuck in the start position and wouldn't kick off...took a new starter home thinking that must be it...put it on (I invented several new curse words in this process ) and still the same result. Decided that it must be a bad battery cable. Drove back into town and got one of those and replaced it. More cursing, same result. Now I'm wondering if it is the relay. I'm about $130 into it now and don't really want to fork out another $30 for the relay if it's not bad. Any ideas? Any help would be GREATLY appreciated!!!
You didnt say what year van you have but Ford uses either the one pictured below or a round one. They both operate the same. There are 2 large terminals and usually 2 small ones. The large terminals are the current carring ones. #1 is connected to the battery and #4 to the starter. When energized, these two terminals are shorted together putting 12 volts to the starter. Terminal #2 is the one that energizes the relay. It usually has a "S" mark above it. When your key is in the start position, 12 volts will be put on this line to energize the relay. To test, you need a test light or volt meter. You can also jump 12 volts from 1 to 2 buy just shorting it with a screwdriver. A relay needs a good ground to operate. Ground is obtained through the mounting bracket. Make sure it it clean and tightly mounted. Terminal #3 is just an output to supply 12volts to the ignition system while in the start position. Sometimes this terminal is not there.
building on what dennis said, try this: remove red cables from terminal number 1. screw them stogether tight and wrap them with something so they don't touch the car (or you'll get a NASTY short). put an ohm meter across the terminals 1 and 4 and have somebody turn the key to starter position. you should get somekind of reading . if not, replace the solenoid.. by the same token, if your helper lets go of the key after you get a reading (assuming you get a reading) and you still get a reading, the solenoid is sticking in the "closed" position. replace the solenoid.... but wait... there's more! if you think the solenoid is sticking by trying this test, switch your meter to dc current, remove the lil wire from the solenoid, and have your helper try again. if you get 12 volts (more or less) but you still get 12 volts after your helper releases the key, i don't think it is the solenoid. but since we are dealing with the ever fascinating world of auto elctrical, before doing this, you may wait until somebody else reads this and verifies my procedures. i'd hate to see you do major electrical damage to your car. best of luck! let us know how you make out!
This is only true if your getting 12 volts to the small "S" terminal while the key is in the start position. I dont recommend trying to read current unless you know what your doing. Current is measured in amps. Current through a small coil like the solenoid is not much, but if you hook it up wrong you can smoke your meter if its not fused. Stick with measuring voltage. A test light is one of the best tool you can put in your tool box. If the solenoid is sticking, the starter will run all the time.
testing 101 easy, use the "kiss" method. Take the cable that runs to the starter off the solenoid and put it to the battery side, with starter installed. Either it'll work or it won't. And that still doesn't mean it's a bad solenoid. Check for ground at the solenoid and make sure your engine is grounded good also. If the block isn't grounded the starter current ain't goin happen. Solenoid ground bad, ain't happenin either. Most people change the solenoid thinking it's bad when alll they do is fix a ground problem when the make the change out.
uhhh i wasn't checking draw... just continuity across the starter side of the solenoid... i need to learn to make myself more clear
This part caught my attention. Do you mean that when you turn the key to 'start' you hear the solenoid making a real loud vibrating kind of buzz? This usually mean the starter is not getting enough juice(battery needs charging or is bad, cables are making a bad connection, etc.) Generally the solenoid does not buzz when it is energized, although I have observed a faint humming when I have the car connected directly to a "fast" battery charger and some of the AC is getting into the car's electrical system...
Thanks Guys...I found it Thanks everyone, After I posted the message and then went off to work the next day, I had time to give it some thought and cool off a little. I decided it probably was a bad ground somewhere. I removed the negative battery cable and found a bad spot on it where it had rubbed against something. Replaced the cable ($10) and it fired right up. Word to the wise....don't work on your ride when you've only slept about 5 hours in 2 days. It definitely impairs your decision making ability. I didn't think this deal through completely from the beginning and wound up forking out a little over $150 when I should have checked the obvious things first. Oh well, live and learn....
grounded gee seems like that was mentioned in a post earlier. They ain't no good if you don't read them.
Tell me about it... I posted the message and then had to go to work, I'm a firefighter. I thought that I would be able to check on the replies while at work, but the IT guys from the city are hooking up fiber-optic cables so I couldn't access the net to check on the progress. The next morning, we had some guys call in sick (sunny & 70 ) and I had to work an overtime shift. Oh well, I had some time to think it over, and figured I had replaced everything else, so I checked the cable when I got home and realized where the problem was. I sure appreciate the responses though. The next time I hope I can help someone else. BTW 48 hours on duty is no fun. I do it all the time, but it doesn't seem to be getting any easier.
