QuestionQUESTION: i have a 2001 dodge dakota tht wont start when hot but does when cold. WHen warmed up and i try to start all i get is clicking from three relays under hood. fuel pump relay, engine relay, and rad fan relay. after awhile ill try again and i can here fuel pump click on and truck will start. summer is here in florida and truck would not start at 2pm after sitting all day in sun. thanks for the help
ANSWER: Hi Travis,
When you say "getting clicking" from three relays..." I assume that is several clicks in short succession until you release the key from the start position, correct, or is it happening when the key is simply in the "run" position, before you move it to "start"?
That general behavior of relays happens when the voltage on the system is too low to lock up the relays in their closed position. It could be due either to the battery being low in charge/reaching the end of its warranty life, or it could be due to excessive drain current on the battery even when you have just put the key in the 'run' position, before even trying the starter, which would still point to the battery being the issue. When you turn the key to the run position the voltage should not be drained that much (except for the fan motor which you might try disconnecting if that is the case, and if that prevents the clicking and allows for a normal start then the fan motor might be drawing the voltage down).
If the clicking doesn't happen until you move the key to the start position, then the starter motor may be drawing down the voltage more than it should or again it could be a weak/tired battery.
If you have a voltmeter put it across the battery and note the voltage to begin with, then turn the key to 'run', and then turn the key to 'start' to see how much the voltage is dropping down.
Let me know what you learn.
Please read the PS (below) and respond to it.
Thanks,
Roland
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QUESTION: the clicking starts when i put the key to run before i try to start it. if i try to start it ,it will turn over but not start. i will put a volt meter on it tomorrow. the battery os only 8 months old.
ANSWER: Hi Travis,
I would suggest that you check the battery clamps and the far ends of the wires that are connected to the - post clamp to be sure you have solid connections for the battery itself and the return 'ground' pathways that return current to the - post of the battery. Before putting a wrench on the + post clamp disconnect the - post clamp so as to avoid a short circuit should the wrench when on the + post accidentally touch metal nearby.
The relays clicking when key is simply in the run position does nonetheless suggest that the voltage is being pulled down. So check the voltage on the battery with the key in the run position and let me know. The fuel pump relay should close and the fuel pump hum for about 1 second when you turn the key to run, then it cuts off. But when you move the key to start the relay closes again, the fuel pump should hum, the starter motor should respond, and the engine should start. Is the starter motor working properly now when the engine is hot?
The other thing to do is test for fault codes using the ignition key. Turn the key: "on-off-on=-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by a 4-digit number preceded by P. If so, let me know the number.
Thanks for the rating and nomination which you are entitled to do again is you would like.
Roland
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QUESTION: hi thanks for your help. ive rated you a ten. i had the battery checked and it is good as new. 12 volts when in run position. it will start still when cold. sometimes when i turn to run it will click a couple times, then it quits and i will hear fuel pump hum for 1 second then when you turn the key it will start. but other times it will just click repetitively. the clicking is coming from three relays. ive changed them and had no success. i get a "no bus" code sometimes from the odometer window. no other codes appear.
sometimes to get it to start i will just keep turning the key back and forth from off to run until i hear the fuel pump. i dont understand why it will start 5 seconds after it didnt start. and if it was the fuel pump why would three relays be clicking? thank you for your time
AnswerHi Travis,
I notice that the fuel pump and radiator fan relays are both powered by the same fuse and that fuse is powered by a specific section of the ignition switch, and that section of the ignition switch is also powered by a single fuse. So it would be good to check the voltage on both sides of those 2 fuses when you have the problem that you describe because it may be that one of the fuses has a crack in its internal wire which opens and closes spontaneously when it is drawing current through it or the ignition switch section may be flaky. The fuses in question are fuse E (20 amp) in the power box under the hood, and fuse 10 (10 amp) in the fuse box in the cabin. So use a voltmeter to look at the voltage reading on both ends of those two fuses when you are having the problem and the relays are clicking so as to notice if the voltage is fluctuating on one or both sides of the fuses that I listed in synchrony with the clicking.
By the way, I am not clear what you mean by the 'engine relay' which you said also clicks when you have the problem. What is its purpose, does it have another name?
Thanks for the earlier rating and nomination. You are allowed to do that again for each of my answers if you believe that I deserve it.
Roland
