New engine - but is it getting fuel?

[NotEnoughTrucks]

I'm going to go visit my old cab this weekend. Hopefully, I can get some pics of the area in question.

2 days of work came my way and our springtime weather is taking its sweet time in arriving this year.

[sgauvry]

Yes.  We have snow melting from a 10 inch drop we had last week.  Supposed to be 52 today but nothing but rain between now and Saturday.  Temps around 50 each day.  Finally!

[sgauvry]

Hey gents -

Few things to update -
Found what I think is the tank selector switch. Here are some pics:





There are only 5 poles to connect to inside the switch, but there are 7 wires coming to the back of the switch.  2 jumpers, possibly?

Here's the bad news:  The ignition switch that is bolted to the steering column totally came apart.  However, prior to doing so, I had a tremendous billow of smoke coming from the starter solenoid and voltage regulator area of the truck.  Since the ignition switch started to come apart as I turned the ignition key to off, it would not stop the process of cooking components.  Had to run over and disconnect the battery.  The cooking of components meant that, even with the ignition switch replaced with a new one, I now have NO power coming to the dash cluster.  That means no gauges, no wipers, no turn signals/flashers, no heater, no cranking, NADA!  I do have headlamps and dome light.  The engine will crank when jumping the solenoid.  

All fuses are good.  Is there a hidden fuse box I do not know about?  Possible bad voltage regulator?  Shot inertia switch?  Ideas?

Thanks, gents!  Can't move forward to this gets figured out.  

[Gary Lewis]

Ouch!  That's gonna be a problem.

First, you will need to acquaint yourself with this section of the EVTM: Electrical/EVTM/1986 EVTM/Charge & Power Distribution.  There you'll see several fuse links, one or more of which is probably fried.

You can usually tell a fried fuse link because when you pull on it the wire is gone inside and the insulation will stretch.  Fuse Link L feeds the headlights so it must be good.  But Fuse Link M feeds the ignition switch and that is the likely culprit.  

[sgauvry]

Hi Gary -

Yes.  I have been looking at that.  Not seeing a fuse link M.  

Page 15, 16 - (With Alternator Warning Indicator) Gasoline (without auxiliary battery)
Fuse links I, H, G, F, E, N, S, D, B, C, P.  There is no Fuse Link M.  

Fuse link E, possibly?

Will also tell you I checked voltage downstream of each fuse link.  12.4 volts on all readings.  

Thanks!!

Steve

[Gary Lewis]

Look at Page 20 Figure 1.  Granted that's for the diesel, but I'm pretty sure that M was in the same place for a diesel as a gasser.

[sgauvry]

The pic on page 20 is for an aux battery and M is for a system with an ammeter.  On that page, fuse G is for the alternator warning indicator, but also for a system with an auxiliary battery.  Or am I reading this wrong?
Back to pages 15 - 16, Fuse link H runs to the ignition switch, wire 37 yellow.  Will also check Fuse link E wire 38, bk/o runs to fuse box.  

Sound like a plan, man?  

[Gary Lewis]

Fig 1 on Page 20 is looking at the passenger's side fender, and is not for an aux battery, which would be on the driver's side.  And, Fuse Link M is for all vehicles in 1986 as they appear to have included an ammeter on all of them.

For 1985 the EVTM shows that it is called Fuse Link I for vehicles that have a warning light.  But it is the same circuit #37 with an orange 16 gauge link (the 1986 is a green 14 gauge) that goes from the starter relay back to the yellow wire going to the ignition switch.  

[sgauvry]

Yep!  Fuse Link I is the one!!  Will check that next chance I get.  But if it's sending through 12.4 volts downstream of the fuse link, it is ok, right?

Thanks!!

[Gary Lewis]

Yes, if you have voltage downstream then it must be good.  But remember to fix whatever shorted before you replace the fuse link.  You can buy fuse wire at many parts stores.

[sgauvry]

Gary Lewis wrote

Yes, if you have voltage downstream then it must be good.  But remember to fix whatever shorted before you replace the fuse link.  You can buy fuse wire at many parts stores.

I checked all of the fuse links after things got toasted.  All are showing 12.4 volts downstream of the fuse links.  

I have since replaced the cause of the barbecue (the ignition switch).  

Since all fuse links are good (I will double check but I did check them all before) what is the next step?

[Gary Lewis]

I'm confused - even fuse link I is good?  If they are all good and you've replaced the culprit then proceed on with trying to start it?

[sgauvry]

Yes.  All fuse links are good (read 12.4v downstream of the fuse link) and when the key is turned to the on position, there is no power same as if the key is in the lock position.  No gauges, no turn signals/flashers, no wipers, no heater, etc.  Just headlamps and a dome light.

I'll re-check and get back to you.  I'm interested in the fuse link wire that runs to the fuse box as well, Fuse Link E.  

Will try to do it today and let you know.

Thanks, Gary.  

[sgauvry]

Tested again - Fuse links that were tested are fuse links to the starter solenoid. All tested at 12.4v.  As I said before, with key turned to the on position, there's no power to gauges, turn signals/flashers, heater blower, and when turned to start position, no cranking.  I do have headlamps and the dome light.  

Fuses are all good.  Since it'll crank with the starter solenoid jumped, the solenoid must be good.  The voltage regulator was likely fried, but that wouldn't cause the no-power issue I'm having.  Right?

What else is there to check?  Shot fuse box?  Shot safety switch?

[Gary Lewis]

Circuit 37, as shown on the previous link, feeds the two parts of the ignition switch shown on Page 16.  So, if the fuse link is bad then none of those things would work.

But, it is possible for the fuse link to be bad but still show 12v if you don't have anything turned on.  It could have a really poor connection internally such that it won't run anything but still give a decent reading when the ignition switch is off.

So put your volt meter on and then turn the key on and see if anything like the heater works and what the voltage does.

[sgauvry]

Gary Lewis wrote

So put your volt meter on and then turn the key on and see if anything like the heater works and what the voltage does.

The problem is that there's no power to anything except the headlamps and dome light.  The heater blower has no power.  So the test won't work.  Other ideas, possibly?

[Gary Lewis]

I understand that nothing runs.  But, if there is 12.4v at the tail end, meaning closest to the cab, of Fuse Link I then we have to figure out what is going on.

One possibility is that you get 12.4v on your meter when everything is turned off.  But, if you try to power something then that voltage goes away.  So, have you tried to test the voltage while the key is on and the blower is turned on?  If not, please try.

If you have, then you need to check the yellow wire going into the ignition switch.  See if it has the 12.4v - both with the switch off and with it on.

[sgauvry]

Ok!  That worked!!

There's a single wire coming off the solenoid that has two fuse links spliced to it.  The wires on both fuse links appear to be orange and black.  One of those runs to the main light switch and one runs to the fuse panel.  My guess it is the one running to the fuse panel.  

So, is this a matter where I replace the entire wire, or just locate a bad section of wire?  

Thanks, Gary!  You're on it, again!!!

[Gary Lewis]

Yes a 16 gauge fusible link.  That should be what is bad as it is at least one if not two sizes smaller than the rest of the wiring harness and is designed to fail there.  But, it isn't just smaller wire.  It has a flame-proof insulation that won't melt off when it gets really hot.

So go find some 16 ga fuse link and replace the one that is burned.  

[sgauvry]

Thanks again, Gary!  Let us hope this is the last issue with the electrical components.  

I ordered several fusible links, of different gauge as specified in the EVTM, enough to cover the wires going to the solenoid.  Might as well replace them all while I'm at it!  

Steve