No power!!

[aasltmike]

Got in the Ty this morning to go to work and cranked the engine. It started turning over briefly then died with dash lights and dome lights on. Turned the key to the off position and went to crank again and nothing lit up! :rant: No dash lights, no ignition beep, the alarm did not go off, no dome lights. Checked my connections at the battery and checked fuses in the fuse panel. All fuses are good, cables between the battery, ground, alternator and starter are good and no blown fuses. Used the multimeter on the battery and it's showing 12.3 volts. Anyone have a troubleshooting logic tree for no power, no start? Hints on where to start?

 

[the baPhoon]

Re: No power!!

I had the dreaded purple wire ground out and cause the exact same symptoms. Insulation was missing in huge sections grounding on the firewall. :shrugs: just a thought.

 

[Don W.]

Re: No power!!

Check the fuseable links at the alt.

 

[aasltmike]

Re: No power!!

Will have to check both those options there. Already checked the fuse at the alternator and it was good. Didn't think to check those fuseable links, though. One other symptom I forgot to add was now even with the key in the off position and the door open, I have no dome lights. Absolutely no power whatsoever, but when I took the positive cable off the battery and put it back on the post, it sparked a little.

 

[gkrcr882]

Re: No power!!

I had the purple wire short out on my DP once too, saw a puff of smoke from the fusible link. Scared the crap out of me. Also check your ground connections, for it to be affecting the whole truck it has to be a fairly large open in either the B+ or ground side.

 

[Don W.]

Re: No power!!

I had the purple wire short out on my DP once too, saw a puff of smoke from the fusible link. Scared the crap out of me. Also check your ground connections, for it to be affecting the whole truck it has to be a fairly large open in either the B+ or ground side.

Don't know 'bout Ty's but on the Sy the entire truck is fed off those two links, Except the CHAC (10a at the alt.) Unless you've modded it. If you did fry them then you'll need to find the cause.

 

[BoostedSUV]

Re: No power!!

Check the ground to the back of the head, the connection at the alternator, the connection at the dist block on the firewall, and as mentioned the fusibile links. Those are the main wires controlling just about all power to the truck.

 

[sly dvl]

Re: No power!!

I'd double check your battery. Leave your meter on the battery and open a door or turn on some lights. If the voltage holds then the battery is reasonable. I've seen/had batteries that show decent voltage, but as soon as you put the smallest load on them - nothing.

Just a thought...

 

[aasltmike]

Re: No power!!

Can't check the battery that way because I have no power at all coming into the truck to put a load on the battery. Gonna take it out and get it tested at Advance to see if the battery is bad. Fuseable links tested good and I'd done the Big 3 upgrade on my cables with 2AWG wire. Tested continuity on all those and they were good, too. Purple wire is good, too. When I did the Big 3, I wrapped the purple wire in heat-resistant tape, put split loom around it and wrapped that in heat-resistant tape, too. More to come, though.

 

[sly dvl]

Re: No power!!

That's what I'm saying. They battery may have an open-circuit-voltage reading (12.3 volts) but as soon as you try to pull any current out of it the battery falls on its face, giving you the impression there's no connection to the rest of the system because the battery is now down to 3 (as an example) volts.

Put a meter on it and turn something on. If the voltage remains the same then you know you have a wiring issue.

If there's one thing I've learned in 20 years of wrenching it's "check the simple things first".

 

[aasltmike]

Re: No power!!

Did the check like you said and voltage stayed the same. So, now I know it's wiring. Tracing the wiring schematic, power comes off the positive battery post into the starter solenoid then into the purple wire. The purple wire then changes to yellow going into the ignition switch on top of the steering column if I read it correctly. Did I read it correctly? I did a continuity test on the purple wire to the yellow wire into the ignition switch and no continuity. If the purple wire does turn to yellow going to the ignition and did the continuity check right, then it would seem my purple wire grounded out. Here is a schematic I marked with colored arrows. Am I tracing the circuit properly and do I have the flow right? If I do have the routing right, I am going to re-check continuity tomorrow and go from there.

 

[sly dvl]

Re: No power!!

Close, but no cigar. :lol: Your arrows are backwards. The battery cable does head down to the starter, but is attached to the "B" terminal on the starter solenoid. From there, there should be several fusable links (although your schematic doesn't show any. Maybe they all come off the alternator?) that then feed into your fuse box.

The purple wire comes FROM your ign. switch and is connected to the "S" terminal on the solenoid. This is the signal to the solenoid to begin the cranking sequence. Current leaves your ign. switch and goes into the starter solenoid, and then to ground. This action closes a high current switch in the solenoid and allows a large amount of current to flow into the starter and then to ground.

In short, I'd suspect a fuse link has failed. Give each link a gentle tug. If it stretches and comes apart, there's your problem.

 

[aasltmike]

Re: No power!!

My fuseable links are on the back of the alternator. I'll check on those tomorrow to see if they come apart. Continuity can be checked on those if they don't come apart, yes?

 

[sly dvl]

Re: No power!!

Continuity can be checked on those if they don't come apart, yes?

Absolutely. But I'll bet a gentle tug will do it...

 

[Don W.]

Re: No power!!

Fixed????

 

[aasltmike]

Re: No power!!

Not yet. Work and prepping for my leave starting on Saturday to go visit the wife's family in Missouri for Christmas. I meant to let sly dvl know that I tried pulling on the fuseable links yesterday, though. I had to pull pretty good on them and they did not come apart. I tested continuity on them and continuity is good. I'll get a chance to work on it some more this afternoon. Would like to get her up and running again before I head out this weekend, so we'll see.

 

[sly dvl]

Re: No power!!

Damn. I was really hoping that was it. My Sy has a few more fuse links on the firewall coming off a plastic block. This is also where the hood light gets its power from. I assume Ty's are the same, so that would be the next place I'd check.

 

[aasltmike]

Re: No power!!

Damn. I was really hoping that was it. My Sy has a few more fuse links on the firewall coming off a plastic block. This is also where the hood light gets its power from. I assume Ty's are the same, so that would be the next place I'd check.

I'll check to see if my Ty has those this afternoon and let you know.

 

[sly dvl]

Re: No power!!

One more thought after reading your initial post again. Where are you getting the 12.3 volt reading from? I know it's your battery, but do you have a dual terminal battery (top & side posts)? I ask because I have seen the plate straps break internally leading to the side posts, while the top posts remain unaffected. Do you have 12.3 volts @ the alternator stud?

 

[Don W.]

Re: No power!!

One more thought after reading your initial post again. Where are you getting the 12.3 volt reading from? I know it's your battery, but do you have a dual terminal battery (top & side posts)? I ask because I have seen the plate straps break internally leading to the side posts, while the top posts remain unaffected. Do you have 12.3 volts @ the alternator stud?

Good point. And if that's the case they make little converter cables to go convert from top to side posts. Although, if so, might want to change the bat anyway.

If there's 12v at the alt term it doesn't mean there's 12v getting to the truck. Just remembered aren't there a few fuses that are hot all the time? Should check there also. My main (full S series wiring diag) book is at the shop or I'd check. And, as has been mentioned, 12 volts at the bat doesn't mean there is enough amperage coming down the line to run anything. I've seen that before also.

Just thinkin' out loud...