Electrical Gremlin

[20fathoms]

Howdy all,
I was a TDR member over ten years ago and its great to see the original forum is still going strong. I'm looking for some help with an electrical gremlin on our bone stock 1990.5 non-IC W250 with a G360 and NP205. More background below but does anyone know what the relay/resistor in the attached pic is?
Three spade with pink, yellow, and yellow w/pink tracer wires. The three wire pigtail appears out of the main harness under the dash next to the clutch pedal linkage. This relay/resistor? has 22.4 ohms across the top horizontal spade and the vertical one (closest in pic). I have an FSM w/ wiring diagrams for the 1991 and later vintage but I can't seem to positively ID this relay/resistor; there are no readable markings on it.

Background:
The truck been mainly used in the pasture for the last 6-7 yrs and we're trying to get it road ready again. Recently replaced starter solenoid brushes/plunger, lift pump, and throttle shaft bushing and top side seals on the IP. When the starter failed, the dash cluster WTS and "brake" lights stopped working, radio went out, I could not hear the grid heater cycling, no seat belt chime, and KSP went out (diagnosed by white smoke until warmed up). I'm guessing the preceding failures are due to a fusible link or two. The speedometer hasn't worked since '97 and I dug into that this weekend. R&R'd the dash/inst cluster to test the all the wires and circuit boards. Once back together, the truck would not start - with the key on, the key halo, turn signals, headlights, all worked but she wouldn't crank, no sounds whatsoever...no even a click from the solenoid or starter relay. Thinking clutch safety switch I dug around under the dash and found that the pictured relay/resistor? was waay hot, to the point I could only hold it for 15 secs or so before I had to let go. I'll bypass the clutch safety switch (just for a diagnosis) and test the fusibles next but would appreciate any input on what this relay/resistor is and why its so hot when the batt hooked up and truck off

Many thanks in advance.

 

[DavidC]

Looks like a flasher. I do not know if they still used a voltage regulator for gauges as the one's I use to see plugged directly into a board behind the gauges.

Dave

 

[20fathoms]

Thanks Dave. Would a gauge regulator show continuity with 22+ ohms? The yellow wire has me thinking ignition but that's just a guess

 

[DavidC]

Yes it could. Guess one way to find out is to see if gauges work with it unplugged.

Dave

 

[DavidC]

#ad

This is the regulator I found for 1990 instruments so I guess that is not what I may have thought. Hopefully somebody knows if it is not for turn signals or 4 way flashers.

 

[mwilson]

I had a fuzzy recollection that the thingy was a timer for the ignition halo....and I think I recalled correctly..

It gets hot by nature...

https://www.rockauto.com/en/moreinfo.php?pk=932681

 

[20fathoms]

Thank you Dave. With the "thing" unplugged I still had blower motor, voltmeter, headlights, turn signals; it still won't crank to I can't test temp and oil. I manually checked the fusibles on the driver's side fender well and they all felt solid, no evidence of burn-outs or easy stretching...I kind of hate to perf a wire to chk continuity but it may have to happen. Troubleshooting the starter relay now, so far no crank with the batt and ignition terminals jumped; ground is next.

 

[20fathoms]

MWilson, thank you! That looks identical to what I have...low and behold when I unplug it the halo turns off, didn't notice that on my initial check. Dave thank you as well for digging in on my problem.

 

[RWherley]

Could be your ignition switch is bad, I had a issue a few years ago where mine would crank but would not open the shut down plunger on the fuel pump to let it run

 

[20fathoms]

After retracing my work I discovered the plug joining the vss wires (and others) to the main harness at the passenger firewall was not fully seated...a craniorectal inversion on my part. She now fires right up. Thank you all for your input!

 

[Steve Graham]

The item in pictures 1st post is the timer for the glow ring around the ignition switch. See schematic page AD 53, called the ignition lamp time delay relay.