Hi,

even after motor has started, the starter still cranks (when key returns to ignition position). I need to remove the keys to have the truck stop cranking.

What can it be? Is it the starter relay? can it be something else?

Thanks,
Leo

 

If you remove the wire with the rubber boot from the starter relay does it stop cranking?

If it does the most likely problem is a short in the ignition switch.

 

Hi 87 XLT!

I tried and it doesn't.

 

In that case, it sounds like the contacts in the relay are fused together & you need to replace it.

Edit, something does not compute here.

If the starter relay is fused together the only way to get it to stop cranking is to disconnect a battery cable, but in your 1st post you said removing the key from the ignition would stop the cranking.

Did you remove the negative battery cable?

 

That sounds right but what's strange is that I bought the truck a year ago and the relay seemed new at that time or freshly installed. We started having snow yesterday, it's probably the humid temperature having the relay to arc. Even then I'm wondering, usually relays are robust and last long.

Could it still be the ignition switch malfunctioning?

Thanks!

 

Yeah, it could be, but i'm still not exactly sure what this thing is doing.

Time for a simple little test.

Pull the wire with the rubber boot off of the starter relay.

Connect your voltmeter to the wire & connect the negative lead to the negative battery post.

With the key off you should read ZERO volts.

Turn key one click & you should read ZERO volts.

Turn the key to start & NOW you should read 12 volts.

Try this & post back with your results.

 

Wires on starter relay are tight and clean. Hoe to check a leaking relay if that is?

I forgot to mention, the starting problem only occurs for 30 secs to a minute.

Thanks,
Leo

 

Well those voltages are good, so it looks like the problem is the starter relay hanging up.

I read a thread from a guy who had replaced the relay 4 or 5 times & kept having this same problem.

He decided that tightening the nuts on the relay was somehow distorting the relay & causing the contacts to stick closed.

He cured the problem by using 2 nuts on each of the large posts. You might want to try that.

 

87 XLT,

First, thanks for all your help. Finally, I think the problem like you mention has no choice to be the relay unless that there is another part that I'm not aware of that could interact the voltage path. Those relay must be cheap made, the canadian dealer just told me they sell alot but gave me reason that they fit on lots of models...they still sell alot from my point of view so that probably makes it cheap made. They sell it for 43$.

I'll take your advice and lock them with dual nuts to keep tension of the post.

Thanks again!
Leo

 

Good luck with it & I hope that cures the problem.

 

Leo, that $43 must be C$, right? In US, I think I paid less than $20, and closer to $10 for a relay. I did not get a FoMoCo part, but got an aftermarket from Advance.
It was doing what I think you describe. Scared the beans out of me when I let go the key and it kept cranking. I jumped out of the truck and pulled the small connector on the relay and it kept going. Finally pulled the battery cable to make the starter stop. The same relay fit my wife's car, and it finally quit after 240K miles. On her car, I'd move the key and nothing would happen. Anyway, good luck.
tom

 

Thanks 87XLT!
Tom, it did scare the hell out of me, it was a total loss of control, I didn't know what was going on since it was the first time I was experiencing such a problem. The only way I found at that moment to kill the truck was to put it in gear and hold the brakes. Yes 43$ CDN from the dealer for a Motorcraft, I decided to buy a good quality jobber one they referred me to the ''Standard'' brand name for 21$.
I didn't install it yet, I'll have to wait this weekend for extra time. It's less cold this week and it has only done it once and for 3 seconds.

Guys, again, thanks for all the support. I'll let you know if it wasn't the source of problem.

Leo

 

Hi Guys!

I just changed the starter relay and I have the same problem.

I have no clue of what it can be now. I've rechecked the positive sense snap on cable that goes on the relay and voltage readings are correct. 12V is only present when the starter is engaged with the ignition switch on ''start'' position.

Anyone has a clue?

Thanks in advance,
Leo

 

Leo, the new relay may not be working correctly. Once energized, it is keeping the path connected internally from the + terminal on the battery, through the large cable to the connector on the relay, through the relay, through the large cable to the terminal on the starter.
That is the only way for power/energy to get to the starter.
HOWEVER:
If your starter is stayed engaged and connected to the flywheel, not energized by the battery, but being spun by the engine, then you need to remove the starter and clean it up or inspect the teeth on the fllywheel and the starter to see if there is a wear pattern that could be hanging the teeth together.
tom

 

Tom,

all the way I thought it was an electrical problem but as time pass by, I think it's more a mechanical problem. I doubt it's the relay, it's brand new and I believe in their solidity. Like you point out in your second affirmation, the problem is most probably the starter that is kept engaged in start. I'll remove it and try to clean some pieces, if doable.

Thanks again for your help,
Leo