Weird wiper/washer-related(?) issue

[Rich_NYS]

I just realized it' appears to be unrelated to the wipers, but can't edit the title (??)

I've been diagnosing a "no wipers" condition. Today when I resolved it and was testing, I noticed another issue: when I flash the high beams, the fuel pump energizes when I release the lever (WTF?!) I also don't have washers, and don't hear the washer pump. I also noticed I don't hear the fuel pump energize when the key is in the "on" position, but the car runs fine (so obviously the pump gets power when cranking.)

I think there could be a wiring hack under the dash, I'll post a few pics.

[Bitsyncmaster]

The RPM relay is looking for an ignition pulse to run the fuel pump. Switching electrical loads can cause the ignition ECU to fire a pulse. I have seen it happen on my car which did not have the capacitor on the idle switch circuit. Hitting the gas without the engine running would fire the RPM relay to prime. I would not think the headlights would cause an ignition pulse since most of the wiring is forward of the ignition circuits.

Most electrical noise in cars comes from switching of inductive loads but incandescent bulbs do draw a high current when first powered on because the element in the bulb when cold has very low resistance.

[Ron]

I've seen several Ds that would 'prime' the pump when flashing the high beams. Cycling the switch, bumping the starter, charger/jumper cables...can do it too.
I'd ignore that for now and disconnect the washer pump and feed it directly with a couple of jumper wires to see if it is OK. If it is, make sure the Black wire has ground. Then look for power along: LGB (LightGreen/Black) wire -> Intermittent Control Module -> Wiper Switch -> Green wire (which has power since the wiper works). You should find the problem/hack along the way.

[Rich_NYS]

Thanks guys, I'll cover all those areas this AM.
I'm troubleshooting a few different things, and seem to be stumbling across additional issues. The wire hack I saw is shown in the pic below...it's a fused wire tapped into the live feed to the ignition switch. I'm trying to trace it, but it disappears into the area above the column so that's gonna require some digging (if I can't find it by removing the inline fuse.)

Additional thoughts on the fuel pump: it doesn't energize when the key is in the "on" position. I'm pretty sure it did a few years ago, but since then I think I removed a relay that becomes optional w/a carb setup.



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[Ron]

Ah, I thought you only suspected a hack. Anyway, there was a factory mod that had a tubular fuse near the brake pedal for the brake lights. IIRC, that was before your VIN, but someone may have done it as an upgrade.

[Rich_NYS]

Ah, I thought you only suspected a hack. Anyway, there was a factory mod that had a tubular fuse near the brake pedal for the brake lights. IIRC, that was before your VIN, but someone may have done it as an upgrade.

I have a few things I'm investigating, the pic is of [what I thought to be] a hack and I thought it could be related to the fuel pump energizing when I flash the high beams.

Also looking into the washer pump not working (low priority for now.)

I want to put my interior back together soon, so I'm focusing on the HVAC mode selector.

[Ron]

Carbs don't need the pump to be primed unless you let them sit so long that the bowl goes dry. OEM systems may or may not prime when you turn them on. It depends on the type of RPM relay, etc., i.e., not required. Manual says it should run one second after the last ignition pulse. Turning it on does not make it pulse... If you turn it on and off quickly several times or bump the starter, it will probably prime.
in other words, waiting on a switch kit is no excuse -- get back to work!

[Rich_NYS]

I've seen several Ds that would 'prime' the pump when flashing the high beams. Cycling the switch, bumping the starter, charger/jumper cables...can do it too.
I'd ignore that for now and disconnect the washer pump and feed it directly with a couple of jumper wires to see if it is OK. If it is, make sure the Black wire has ground. Then look for power along: LGB (LightGreen/Black) wire -> Intermittent Control Module -> Wiper Switch -> Green wire (which has power since the wiper works). You should find the problem/hack along the way.

Carbs don't need the pump to be primed unless you let them sit so long that the bowl goes dry. OEM systems may or may not prime when you turn them on. It depends on the type of RPM relay, etc., i.e., not required. Manual says it should run one second after the last ignition pulse. Turning it on does not make it pulse... If you turn it on and off quickly several times or bump the starter, it will probably prime.
in other words, waiting on a switch kit is no excuse -- get back to work!

Make up my mind!

[Ron]

Make up my mind!

LMAO!

Forget the pump AND get back to work...on the washers (while you wait on the kit).

[David T]

While voltage spikes could make the RPM relay pulse, so could a dip in voltage. Once the dip happens you get a spike when the voltage recovers. Point is the RPM relay is sensitive enough that any large event on the electrical system can make it pulse. That's one reason they can pulse when you turn the key. Bad connections, a weak battery, all kinds of things will affect that RPM relay. If it doesn't pulse, it just takes a couple of more seconds of cranking till you get enough fuel pressure up to start the motor. When it is cold you don't need full pressure to start it, the CSV will squirt at a much lower pressure than the injectors. That will be enough to get the motor to catch till the fuel pressure builds up enough to squirt out of the fuel injectors.