Okay. I thought there was something wonky about those readings. I got the directions for the tests online. I've only ever tested car fuses by pulling and looking at them.

I'll be back.

 

No problem, we’ll get you fixed up.


George

 

think i caught something in this, tested resistance on what? are those fuse numbers? 0ohm outright on a fuse to me says it may be blown, any conductor will have a small resistance load, that is how i test things such as motors or compressors at work, i dont remember off the top of my head what fuse #2 is and if you are referring to an IP Fuse or an UH Fuse, but put the meter in Continuity mode and real quick probe both blades of every fuse in the IP/UH fuse blocks and verify all fuses are correct per the diagram on the cover panels. the meter should beep when there is continuity between the probes and its recommended you check that the probes are continuous with themselves often.

There are small test points ontop of the fuses you can use to avoid having to remove every one. Then do a VOLTAGE check in DC Measurement mode(if multimeter is not autoswitching) KEY ON/ENG OFF, with the fuses George had mentioned, Verify its within a tenth of a percent or so of battery net voltage, measured at the battery cable terminals. you can use nearly any bare spot of metal on the truck including stabbing the F out of a framerail. since frame grounds should keep you within range, if not then you have a battery cable issue to look at also.

 

My mech guy and I Snap-On scanned the bejeepers out of that truck without finding much that was useful.
There were no codes.
The computer saw the fuel level, the battery charge and the engine temp and also saw that the gauges weren't displaying.
We saw no problems with the ignition.

We did voltage readings on fuses 2, 4, 11, 19 and the EMC 1. All were very close to 14.5.
I retested the continuity of those fuses and got straight zeros.

Next, I plan to disconnect the neg battery post and check continuity. An intermittent short could explain the total blackout of the electrics, but not the ongoing non-functioning gauges.

Is there a circuit connecting those gauges that may have gotten broken? Would that cause them to come on, or to go out?

In other news: While poking around with the scanner, I saw a security report that read something like “ (this is) wrong but valid”, which may be the reason my Security light comes on and goes out intermittently.

Also, something I found out and haven't see mentioned here: My key (singular) sometimes gets locked in the ignition. It releases with a faint click after some variable length of time, 5sec to 5 min.

 

OK so what that tells us is that the voltage feeds to the ignition switch, the switch itself and the feeds from the switch to the fuses are all good and your battery voltage/alternator are good . The ignition switch was a primary suspect but not anymore. Do you have the dash apart with access to the IPC and its connectors because next up would be power to the IPC and all relevant grounds.

George

 

double post

 

If you do decide to tackle the connector, power and grounds to the IPC, here is the schematic for your truck. Ill be glad to walk you through it. A simple quick check is the ground attachment point for the gauges which is G201 listed as "right side of dash". That ground also passes through splice pack SP203 on its way to G201 which is listed as behind the ashtray.




George

 

I printed that schematic and I'll take it to the mech, who has had the dash apart while routing the fog light wiring to a dashboard switch. This may not happen until after the weekend.
I'll report back.

 

Now that there is some forward movement, I figure I should update. The problem seems with the instrument cluster.

After a lot of research and discussions, I learned why nobody wanted to take on the job; cos it's a time consuming PITA, so I ordered a soldering station that arrived today. I have a friend who repairs old circuitry as a hobby and agreed to tutor me one the operation. I also have the very similar instrument cluster in my parts-car Blazer to practise on. My Jimmy still runs with the bezel and dash hanging loose, so it may be some time before the end of this story, which I will report when it happens.

Also – it appears that the dead truck scenario was likely due to a loose battery connection left over from the fog light install.

Thanks George and all who responded. I'll be back.

 

Let me know if you need any guidance with soldering. I’ve been thinking about doing a soldering tutorial anyhow.

George