Electrical question

[miket]

Hey guys (and gals):

I need some help. I have a 71 Cheyenne 1/2 ton, 350 4 barrel with auto trans. Truck is original and in very good condition. Problem is, I pressure washed the engine compartment today and now the truck will not fire.

Essentially, I covered the carb and cleaned everything (like I have done many times before). After putting the air cleaner back on and connecting all of the hoses, I attempted to start the truck. It fired once and then died. The starter works fine and spins the truck over. It has the original standard ignition setup with points and coil. I removed the Distributor cap and of course found a bit of moisture which I cleaned out...still no fire. I ended up replacing the coil and condensor and tested for juice at the coil while starting....6.5 to 7 volts...sort of odd. Battery is new....truck drove great all day today before I decided to clean the engine compartment ( Iguess thats what I get!). I also hooked up a timing light and looked to see if I got anything while cranking...nothing.

I understand their is an ignition coil wire that is energized off the starter solenoid...does anyone know if this could be the culprit? Any ideas?

[Longhorn Man]

The coil you mention while cranking is the same coil that you just replaced. IT should be getting a full 12 volts when you crnak it....check for a yellow wire going from the starter, to the coil. This is just to make start up easier, and not really something that should keep you parked.
Since you placed a timing light on there and got nothing, then for one reason or another, there is no power getting to your wires...at least, not the #1 wire.
I would go back in the cap, check for any moisture, (WD40 sprayed in there will help to displace it) and double check (even replace) your points and condenser. Look at all the wire connections on your coil and the like.
As for your cleaning practice, if you have a stock air filter assembly, there is no reason to cover it. I normally keep mine running while I spray it down. A little water going into your engine will actually help. It vaporises, turns to steam, and knocks carbon deposits off of your combustion chaimber. This is an old school trick to help with an emissions test. However, we are talking very small amounts...not shoving the spray nozzle in the carb.

[SWINGSAX68]

I would go over the Distributor once again.......try using a blow dryer to dry the cap and then once over the innards. might work. moisture can stay in there for a lot longer than one would think.

[ChevLoRay]

Old trick.....use toilet paper to dry out the distributor cap, etc., following washing the engine. Use it on all electrical connections to wick the water out of the nooks, cracks and crannies that can hold it. Also, WD-40 will displace water in other places. You can look on the label to see if usable for your problem. Also, there are electrical cleaning sprays that may prove helpful.

Next time: Use a gallon-size baggie and cover the distributor. Take a medium to large size plastic margarine container (empty, of course) and turn it upside=down over the carb. You can make a hole in it to fit the hold-down screw and use the wingnut to hold it on.

Finally, consider going to an HEI ignition system. It's more reliable and the cap doesn't have that sliding door in the side to let moisture in.

Just my nickels-worth.

[miket]

Okay guys and gals:

Thanks for your posts. I got it fixed! for what it's worth here is what I learned...

The yellow wire coming from the starter (going to the + side of the coil) is the one and only wire that energizes the coil...

The OEM coil requires a resistor that apparently steps down the voltage...

This resistor is not needed on some aftermarket coils (even though they don't mention it in the instructions)...

Completely cover the distributor and carb when pressure washing the engine!

Thanks averyone. The distributor was still wet where I couldn't see and I used the coil resistor on a new aftermarket coil that didn't require it, so I disconnected it, sprayed WD40 in the distributor and it fired up.