Fuse 19 (Hot in start or run) blowing
#1
Fuse 19 (Hot in start or run) blowing
So my 96 ranger died while I was driving. I thought it was the fuel pump but later found it was fuse 19 which was blown. The fuse runs runs to the pcm relay's coil and also goes to the ignition coils..
so after i realized the fuse was blown, i replaced it and the truck started and blew the fuse again after a few seconds.
I was checking for shorts in the pcm relay and ignition coil wires and gave it 1 more try with a new fuse in and it ran fine.
I am scared to go for a drive and have the truck fail on the road again.
any ideas or anything i should check? Can a faulty ignition coil blow this fuse?
so after i realized the fuse was blown, i replaced it and the truck started and blew the fuse again after a few seconds.
I was checking for shorts in the pcm relay and ignition coil wires and gave it 1 more try with a new fuse in and it ran fine.
I am scared to go for a drive and have the truck fail on the road again.
any ideas or anything i should check? Can a faulty ignition coil blow this fuse?
#3
Unfortunatly the same thing happened 2 me.19 blew then i put a new one in started up ran for 2 days then it blew again.put a new one in drove around the corner and it blew again. so i put in a new one and it blew right as i cranked it...i probobly blew 5 fuses trying it... i took everything apart and thought it was my pats moduel,when i put evrything back in it would start after i played with the pats everytime..2 days later.it blew again..i opened the fuse panne put anoher one in it started but if i touched the fuse it blew..i thought it was a short in the use block itself...untill i relized if i pulled out the fuse to the right of 19 tried cranking it put the fuse back in it starts and runs fine....now it dies and blow when i give it gas in reverse wtf!!! idk what to do anymore...
Last edited by 01prerunner; 08-08-2011 at 03:01 PM. Reason: spelling errors
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Donbran (10-19-2020)
#7
2001 Mazda B3000
HELP....so last week my truck died while i was driving it. I coasted to the shoulder and spent 3 hours going throuth the electrical system trying to figure out why everytime i replace the #19 fuse (pcm system/ignition coil) it instantly blows. I ended up changing the electronic ignition switch and replaced the fuse and it ran fine....until yesterday it died again...now I'm stumped...brand new ignition coil, ignition switch, spark plugs and wires, also brand new fuel pump...
#8
RF Veteran
iTrader: (1)
Welcome to the forum
#19 in cab fuse box does power the ignition coil directly, but only powers the PCM relay's coil, .5amp, not PCM or other components, and it power it thru the Power Diode(see below)
It also powers the transceiver in the steering column, the "ring" around the key slot, its a 4 wire connector at the base of the column, red/light green stripe wire may be shorted which could blow #19
In the engine fuse box is the Power Diode for for #19, drawing here: https://www.justanswer.com/uploads/a...12407_bat1.gif
V34, above C101
These rarely fail, but can, pull it out and have a look for signs of overheating
#19 in cab fuse box does power the ignition coil directly, but only powers the PCM relay's coil, .5amp, not PCM or other components, and it power it thru the Power Diode(see below)
It also powers the transceiver in the steering column, the "ring" around the key slot, its a 4 wire connector at the base of the column, red/light green stripe wire may be shorted which could blow #19
In the engine fuse box is the Power Diode for for #19, drawing here: https://www.justanswer.com/uploads/a...12407_bat1.gif
V34, above C101
These rarely fail, but can, pull it out and have a look for signs of overheating
#10
Welcome to the forum
#19 in cab fuse box does power the ignition coil directly, but only powers the PCM relay's coil, .5amp, not PCM or other components, and it power it thru the Power Diode(see below)
It also powers the transceiver in the steering column, the "ring" around the key slot, its a 4 wire connector at the base of the column, red/light green stripe wire may be shorted which could blow #19
In the engine fuse box is the Power Diode for for #19, drawing here: https://www.justanswer.com/uploads/a...12407_bat1.gif
V34, above C101
These rarely fail, but can, pull it out and have a look for signs of overheating
#19 in cab fuse box does power the ignition coil directly, but only powers the PCM relay's coil, .5amp, not PCM or other components, and it power it thru the Power Diode(see below)
It also powers the transceiver in the steering column, the "ring" around the key slot, its a 4 wire connector at the base of the column, red/light green stripe wire may be shorted which could blow #19
In the engine fuse box is the Power Diode for for #19, drawing here: https://www.justanswer.com/uploads/a...12407_bat1.gif
V34, above C101
These rarely fail, but can, pull it out and have a look for signs of overheating
#11
RF Veteran
iTrader: (1)
Its a bit misleading, it doesn't power the PCM system just turns on the PCM Relay when fuse #19 is powered up
PCM relay has a separate fuse that powers PCM, injectors, and other engine systems
Transceiver looks like this: https://i.ebayimg.com/images/g/35cAA...M4m/s-l300.jpg
Its mounted on the key cylinder and the 4 wires run down the column and plug in to the vehicles harness
The connector can be green, white or grey
PCM relay has a separate fuse that powers PCM, injectors, and other engine systems
Transceiver looks like this: https://i.ebayimg.com/images/g/35cAA...M4m/s-l300.jpg
Its mounted on the key cylinder and the 4 wires run down the column and plug in to the vehicles harness
The connector can be green, white or grey
#12
2001 Mazda B3000
So...my tranceiver looks ok, there's no bad wires or anything that looks wrong there, it cranked last time no problem when i changed out the ignition switch, but i can't afford to change the ignition switch every week...could the pcm relay be blowing the fuse or shorting out the ignition switch? I'm horrible at wiring issues...not very good at this lol
#13
#14
RF Veteran
iTrader: (1)
Then I would do this
Unplug the Coil pack
Use an OHM Meter to test the Red wire to Ground(engine metal), it of course should not show 0 or low OHMs
Leave it unplugged and turn on the key, or "key over", see if fuse blows, the coil pack is the biggest amp draw, it runs at .8-1.5 OHMs, which is almost a dead short
If fuse blows it could be Red wire has a short, but ohm meter should have shown that
But pull out the Power Diode, and repeat turning on the key, see if fuse blows, if so all thats left is the Transceiver, unplug it and repeat test by turning on the key
Those are the only 3 devises on that fuse
Coil pack
Power diode
Transceiver
Unplug the Coil pack
Use an OHM Meter to test the Red wire to Ground(engine metal), it of course should not show 0 or low OHMs
Leave it unplugged and turn on the key, or "key over", see if fuse blows, the coil pack is the biggest amp draw, it runs at .8-1.5 OHMs, which is almost a dead short
If fuse blows it could be Red wire has a short, but ohm meter should have shown that
But pull out the Power Diode, and repeat turning on the key, see if fuse blows, if so all thats left is the Transceiver, unplug it and repeat test by turning on the key
Those are the only 3 devises on that fuse
Coil pack
Power diode
Transceiver
#15
Ok
Then I would do this
Unplug the Coil pack
Use an OHM Meter to test the Red wire to Ground(engine metal), it of course should not show 0 or low OHMs
Leave it unplugged and turn on the key, or "key over", see if fuse blows, the coil pack is the biggest amp draw, it runs at .8-1.5 OHMs, which is almost a dead short
If fuse blows it could be Red wire has a short, but ohm meter should have shown that
But pull out the Power Diode, and repeat turning on the key, see if fuse blows, if so all thats left is the Transceiver, unplug it and repeat test by turning on the key
Those are the only 3 devises on that fuse
Coil pack
Power diode
Transceiver
Unplug the Coil pack
Use an OHM Meter to test the Red wire to Ground(engine metal), it of course should not show 0 or low OHMs
Leave it unplugged and turn on the key, or "key over", see if fuse blows, the coil pack is the biggest amp draw, it runs at .8-1.5 OHMs, which is almost a dead short
If fuse blows it could be Red wire has a short, but ohm meter should have shown that
But pull out the Power Diode, and repeat turning on the key, see if fuse blows, if so all thats left is the Transceiver, unplug it and repeat test by turning on the key
Those are the only 3 devises on that fuse
Coil pack
Power diode
Transceiver
#17
RF Veteran
iTrader: (1)
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