burning up pm

[86shelby15psi]

for some reason i keep burning them up there both was used so maybe they was on the veruge of going out or something? its a 86 s/c

[86lance]

prolly have a short with something to do with ur asd going to ur pump,at least thats what ive been told with my pm frying. Otherwise maybe they are just old?

[86shelby15psi]

i hope it that there old

[86lance]

im hoping the same with mine

[turbovanman²]

If you fried 2 in a row, you probably have a short. Check your grounds, make sure there good.
This is how you build a great ground tester, it will find weak ground by actually pulling current whereas multimeters pull like 1/100th of an amp thru. I have find many a bad or weak ground with this simple setup. Grab a old halogen sealed beam headlamp, get the connector-any parts store or wrecker has them. Make sure to use the high beam side-usually the low beam side is blown anyhow-add some lengh of wire-2 ft and some spade terminals. You can grind the terminals down so they fit where the mini plastic fuse goes. This will pull 20 amps or so.

Now, disconnect the PM, find out which wires are ground-hook one side of the lamp to power, now probe all the grounds one by one, the light should glow bright-if its dim-trace and fix the ground, if dead, same-fix, if bright-move on. Check the sensor grounds too. Now when done, hook one wire to ground, check all power wires-they should all be bright. You can also check other wires for grounds and powers that shouldn't be there.

This also works if you keep blowing fuses, simply remove the fuse and insert where fuse went. This lets the circuit work as the filament acts as a resistor. When it glows bright-your short is present-trace, wiggle wiring until it goes out.

[cordes]

If you fried 2 in a row, you probably have a short. Check your grounds, make sure there good.
This is how you build a great ground tester, it will find weak ground by actually pulling current whereas multimeters pull like 1/100th of an amp thru. I have find many a bad or weak ground with this simple setup. Grab a old halogen sealed beam headlamp, get the connector-any parts store or wrecker has them. Make sure to use the high beam side-usually the low beam side is blown anyhow-add some lengh of wire-2 ft and some spade terminals. You can grind the terminals down so they fit where the mini plastic fuse goes. This will pull 20 amps or so.

Now, disconnect the PM, find out which wires are ground-hook one side of the lamp to power, now probe all the grounds one by one, the light should glow bright-if its dim-trace and fix the ground, if dead, same-fix, if bright-move on. Check the sensor grounds too. Now when done, hook one wire to ground, check all power wires-they should all be bright. You can also check other wires for grounds and powers that shouldn't be there.

This also works if you keep blowing fuses, simply remove the fuse and insert where fuse went. This lets the circuit work as the filament acts as a resistor. When it glows bright-your short is present-trace, wiggle wiring until it goes out.

This should be a FAQ if it is not already. Great post Simon.

[Turbodave]

Good advice, I think my old man uses a similar method.

[Lee'sdaytona]

yeah thats a fantastic idea!
-Lee

[86lance]

anything else you could use instead of a big halogen head lamp? i have this exact same problem of a power module going out? If the lamp shines brightly that means that pin for the power module is good?

[GLHNSLHT2]

Just don't stare at the light too long

[turbovanman²]

anything else you could use instead of a big halogen head lamp? i have this exact same problem of a power module going out? If the lamp shines brightly that means that pin for the power module is good?

You need to use a headlight, go buy one, there like $10.

Depends on what your checking-if your checking proper grounds-it will be bright, if you checking power-it should be bright. If your checking shorts-bright is bad-your shorted to ground.

[deuce dodge]

SIMON ROCKS.GO DOG!!!!!!!!!!!!

for us cheep guys go to pic n pay fer a $1

deuce

[86lance]

off to the yard i go to find a headlamp.

[cordes]

off to the yard i go to find a headlamp.

That is where I get the vast majority of my parts from. It really hurts to pay for new parts, when the old ones work just fine.

[86lance]

i actually called my buddy up and he had a few brand new ones layin around so i snagged a high beam one and i think i found my problem

[turbovanman²]

i actually called my buddy up and he had a few brand new ones layin around so i snagged a high beam one and i think i found my problem

Do tell, sheesh,

[86lance]

my number 2 pin on the power module was very dim thru the headlight so i put a wire with a 20 amp fuse in it and it popped immediately,so i jumped power between my battery and my coil and low and behold my fuel pump buzzed on and off,im guessing my fuel pump died( shorted out and ruined my power module)

[Tony Hanna]

This also works if you keep blowing fuses, simply remove the fuse and insert where fuse went. This lets the circuit work as the filament acts as a resistor. When it glows bright-your short is present-trace, wiggle wiring until it goes out.

I used both sides of an 1157 wired into 2 male spade connectors to replace the fuse powering the gauges in my old '78 Camaro. It had an intermitant short and I was too lazy to find it and fix it. The bulb made for an excellent current limiting device and whenever it would get bright and the gauges would stop working, I'd just root around under the dash with my boot until it went out and the gauges started working again.
Yeah, I know that's aweful and I should have fixed it right, but it was a beater and I didn't feel like messing with it.