i had this posted in newbie, no responses, so i hgtd there and moved it here.
I'm sort of scratching my head where to start on this one..... any help greatly appreciated.
I've got a buddy who has a 1993 k1500 extended cab 4.3z tbi 5speed manual pickup. he has been experiencing a bit of a strange set of circumstances for a few weeks and i wont have time to try to assist him until Sunday.
the truck has full instrumentation, no dummy lights, and is all electrically stock.
he had his starter fail on him, so he replaced it. truck starts ok now.
shortly after, it began to act odd.
his charging gauge on the dash drops off to nothing while driving. sometimes the check gauges light comes on, and twice when i drove it today the brake light came on. (non abs, fluid level ok, no brake symptoms whatsoever)
when the gauge dropped, they all dropped. the fuel level, coolant temp, all of them, the headlights dim,.. wipers slow down, and heater blower motor slows.
he figured he had a charging issue, so he went and replaced alternator and battery. then he figured when that didn't solve it he had a ground issue. he installed new grounds, nice beefy clean grounds. one from bat to engine, bat to frame, and bat to body. all clean, tight, new, and well routed. in two or three weeks the truck has never failed to start, nor has it left him stuck anywhere.
this is where it throws me off a bit. when driving the truck,.. you can get it to act normally by dropping to second gear, and punching it. while under substantial load in second gear only, headlights return bright, wipers speed up, blower motor speeds up, all gauges work normally, including charging, and truck runs great. as soon as you shift to third, it returns to its normal problem. i have a snap on micro vats, i performed an AVR, battery tests excellent, alternator passes, idle amperage seems low, about 18 amps, but at the prescribed 2000rpm alt test puts out a recorded 48 amps. starter draw normal. starter mounting tight, connections appear sound and clean.
found and downloaded all required wiring diagrams for truck tonight
I'm wondering what would be the most efficient strategy for inspection. i suspect there may be a short or issue with the i/p , and plan to pull the i/p out on Sunday when i have a little time, to check for burnt connections, or anything obvious, and road-test with i/p out to see if by process of elimination it changes anything. i also plan on inspecting the alternator harness and wiring to check for brakes, abrasion, or pinching.
has anybody experienced anything similar?
cliffs:
93 k1500 4.3z 5sp
runs as if its without appropriate amperage/voltage under all circumstances except hammer down second gear. new alt, new battery, new starter, good battery/chassis/body grounds to battery. no visible wiring burns or failures, passes wiggle tests at idle. batt, alt, and starter verified functioning.
thanks in advance.
I'm sort of scratching my head where to start on this one..... any help greatly appreciated.
I've got a buddy who has a 1993 k1500 extended cab 4.3z tbi 5speed manual pickup. he has been experiencing a bit of a strange set of circumstances for a few weeks and i wont have time to try to assist him until Sunday.
the truck has full instrumentation, no dummy lights, and is all electrically stock.
he had his starter fail on him, so he replaced it. truck starts ok now.
shortly after, it began to act odd.
his charging gauge on the dash drops off to nothing while driving. sometimes the check gauges light comes on, and twice when i drove it today the brake light came on. (non abs, fluid level ok, no brake symptoms whatsoever)
when the gauge dropped, they all dropped. the fuel level, coolant temp, all of them, the headlights dim,.. wipers slow down, and heater blower motor slows.
he figured he had a charging issue, so he went and replaced alternator and battery. then he figured when that didn't solve it he had a ground issue. he installed new grounds, nice beefy clean grounds. one from bat to engine, bat to frame, and bat to body. all clean, tight, new, and well routed. in two or three weeks the truck has never failed to start, nor has it left him stuck anywhere.
this is where it throws me off a bit. when driving the truck,.. you can get it to act normally by dropping to second gear, and punching it. while under substantial load in second gear only, headlights return bright, wipers speed up, blower motor speeds up, all gauges work normally, including charging, and truck runs great. as soon as you shift to third, it returns to its normal problem. i have a snap on micro vats, i performed an AVR, battery tests excellent, alternator passes, idle amperage seems low, about 18 amps, but at the prescribed 2000rpm alt test puts out a recorded 48 amps. starter draw normal. starter mounting tight, connections appear sound and clean.
found and downloaded all required wiring diagrams for truck tonight
I'm wondering what would be the most efficient strategy for inspection. i suspect there may be a short or issue with the i/p , and plan to pull the i/p out on Sunday when i have a little time, to check for burnt connections, or anything obvious, and road-test with i/p out to see if by process of elimination it changes anything. i also plan on inspecting the alternator harness and wiring to check for brakes, abrasion, or pinching.
has anybody experienced anything similar?
cliffs:
93 k1500 4.3z 5sp
runs as if its without appropriate amperage/voltage under all circumstances except hammer down second gear. new alt, new battery, new starter, good battery/chassis/body grounds to battery. no visible wiring burns or failures, passes wiggle tests at idle. batt, alt, and starter verified functioning.
thanks in advance.