1993 S-10 Tail light/blinker issues....

(I only add this next part because it's ironic. When my wife was pregnant with my son, we'd drive by this truck on the carlot almost monthly. I wanted this truck badly, but with a son on the way-it was out of question financially. Then one day I saw it was sold. :disappoin So I gave up on it. Then about a week later my sister in law showed up driving MY truck! Wow- did that hurt! But I was glad she got it. )

My son, who earned his Eagle scout award at age 14, got to buy his "dream truck" a 1993 S-10 Ext. cab w/4.3l engine. It was 1/2 gift, 1/2 for sale, from his aunt/uncle. Very cool. Anyhow it was beater when he got it. We knew it needed a ton of work, but we figured with his determination, a lil common sense & what I knew about mechanical issues, plus our wallets we could get this project off the ground. Fast forward 2+years....


So here we are present day with issues:

With the headlights off, we turn on the L or R blinker....a very faint, and extremely slow blink........pause........blink.........pause..... .blink...
(both front and rear)

Turn on the hazards....both front and rear light up, still dim, but blinking faster....blink....blink....blink....blink....
(still no where near a normal speed of a flash/blink)

So we turn on the headlights.....then turn on the blinkers....both front blinkers work. But nothing in the rear now. Turn on the hazards....nothing in the rear blinkers with the lights on. Still slow blinking however.

We had driven this about a week ago after getting it back from the mechanic. He noticed the gas gauge going up and down irradically. So I figure this is an electrical issue of some sort. Then with this lighting issue I surmise it might be a bad ground. Ok, so I look up top, he crawls underneath and we search for bad grounds=loose, unhooked wires.

We were able to locate a loose/unhooked ground from the engine. We couldn't see where it was attached as it came from between the engine and the firewall. Using a mulitmeter, I zeroed it out in Ohms, and found it was attached to the engine. So I drilled a hole in the firewall (after not finding where it originally came from) and mounted it to the firewall. Then he found a broked grounding strap in the rear of the truck inside the left wheelwell. It was attached to the box, but the other end is broke off. We didn't find the other end anywhere.

We replaced any broke/bad bulbs in the tail lights, and front turn signals. Pretty much covered all the bases. Checked the ground from the battery to the inside wall of the engine compartment. Checked battery connections, fuses, virtually anything I could think of. Nothing.

The mechanic worked on this about a week or 2 ago. He changed out the fuel pump-due to rusty bolts he opted to remove the box and access the gas tank that way. He replaced the fuel pump, filter, transmission filter, spark plugs, and spark plug wires (what a bear that job is!). I don't think he got any wires pinched between the box and the frame-but anything is possible.

Whew! This short story has turned into a novel, but I wanted to give as much detail as possible. Any ideas of what is causing these electrical issues? Thanks for your time! ~Woody :smile:

(I only add this next part because it's ironic. When my wife was pregnant with my son, we'd drive by this truck on the carlot almost monthly. I wanted this truck badly, but with a son on the way-it was out of question financially. Then one day I saw it was sold. :disappoin So I gave up on it. Then about a week later my sister in law showed up driving MY truck! Wow- did that hurt! But I was glad she got it. )

My son, who earned his Eagle scout award at age 14, got to buy his "dream truck" a 1993 S-10 Ext. cab w/4.3l engine. It was 1/2 gift, 1/2 for sale, from his aunt/uncle. Very cool. Anyhow it was beater when he got it. We knew it needed a ton of work, but we figured with his determination, a lil common sense & what I knew about mechanical issues, plus our wallets we could get this project off the ground. Fast forward 2+years....


So here we are present day with issues:

With the headlights off, we turn on the L or R blinker....a very faint, and extremely slow blink........pause........blink.........pause..... .blink...
(both front and rear)

Turn on the hazards....both front and rear light up, still dim, but blinking faster....blink....blink....blink....blink....
(still no where near a normal speed of a flash/blink)

So we turn on the headlights.....then turn on the blinkers....both front blinkers work. But nothing in the rear now. Turn on the hazards....nothing in the rear blinkers with the lights on. Still slow blinking however.

We had driven this about a week ago after getting it back from the mechanic. He noticed the gas gauge going up and down irradically. So I figure this is an electrical issue of some sort. Then with this lighting issue I surmise it might be a bad ground. Ok, so I look up top, he crawls underneath and we search for bad grounds=loose, unhooked wires.

We were able to locate a loose/unhooked ground from the engine. We couldn't see where it was attached as it came from between the engine and the firewall. Using a mulitmeter, I zeroed it out in Ohms, and found it was attached to the engine. So I drilled a hole in the firewall (after not finding where it originally came from) and mounted it to the firewall. Then he found a broked grounding strap in the rear of the truck inside the left wheelwell. It was attached to the box, but the other end is broke off. We didn't find the other end anywhere.

We replaced any broke/bad bulbs in the tail lights, and front turn signals. Pretty much covered all the bases. Checked the ground from the battery to the inside wall of the engine compartment. Checked battery connections, fuses, virtually anything I could think of. Nothing.

The mechanic worked on this about a week or 2 ago. He changed out the fuel pump-due to rusty bolts he opted to remove the box and access the gas tank that way. He replaced the fuel pump, filter, transmission filter, spark plugs, and spark plug wires (what a bear that job is!). I don't think he got any wires pinched between the box and the frame-but anything is possible.

Whew! This short story has turned into a novel, but I wanted to give as much detail as possible. Any ideas of what is causing these electrical issues? Thanks for your time! ~Woody :smile:

Grounds? And or Voltage?
Your Volt/ohm meter is your best buddie on checking grounds and voltage.
Or even a good old type bulb test light will show voltage and ground.

On grounds.
Check battery to engine and battery to frame/engine to frame and cab to engine or frame.
If not grounding good clean/repair ground/or install a new ground wire/cabel.


Is the rear turn signals only electrical problem now?
Just slow blink or no blink or dim light?

Does rear lights tail and stop work good and bright?

Does it have a rats nest wiring where a trailer hight wiring plug in has been tied in with dirty/correded conector?