(DRL)Light and RPM issue

[Muzzy]

Hello All
I have a question about how the DRL should be setup and a strange symptom that may be due to incorrect wiring. There is no module setup in my Van, what has been done is that the low beam lights have been hard wired into the ignition through a relay. So as soon as you turn the key to “Acc” position the low beams come on and when switching back and forth from “NO light” to “Low Beams” it just turns on the side markers. Now here’s what happens, if you turn the Van off take the key out but still have the lights on everything in the van stays on until you turn the lights off. Now everything means the radio, front and rear heater, rear defrost… So what I have done for the time being until I can sort this out is disconnected the relay and I made a little note for myself to make sure I turn my lights during the day. Now everything turns off as it should and now I actually have an “Acc” position. But now what is happening is if the Van is running, and you turn the lights off the RPM’s go from around 700 up to about 950. It does this repeatedly without fail each and every time I turn the switch on and off. I’m not sure what kind of wiring has been done but I doubt the low beams are causing this much of a draw. Any suggestions or places to look before I start taking it all apart to find the problem?
Thanks In Advance

[jessef]

Probably spliced into the same circuit that the A/C is on which would bump the rpm up/down.

When I went through my battery configuration, I found a few pounds of 'extra' wire that was put in at some point.

Best to take a look under there and have the delica wiring schematic printed out as a reference.

[FalcoColumbarius]

Jay, TardisDeli.

[Muzzy]

Probably spliced into the same circuit that the A/C is on which would bump the rpm up/down.

My A/C has never worked. I have taken the belt off and the button is aways disengaged, would this still happen? Sorry this happens everytime I switch back and forth but only when the Van has warmed up.

[jessef]

There is an adjustment on the injection pump that bumps the rpm up when the a/c is turned on.

It's possible that your A/C switch has been spliced into via the DRL. If it was, it could bump the RPM's up 150-200ish when engaged. Have freon or the belt on/off doesn't matter.

[john n]

Install a diode on the hot wire to the headlights.
When the headlights are manually switched on it will backfeed through the ignition when the key is turned off.
If you also wire the relay through the park brake warning light system the lights will only come on if the park brake is off, this is very useful in cold start conditions, you'll have more amp hours available to crank and glow instead of wasting it on headlights.

[jaggedfish]

I have found that any amount of draw on the alternator will lower the revs - thus when you turn lights, rear defrost, etc off the engine revs will pick up. This is most noticeable when in park or neutral as there is no other load on the motor.

John N is on the right track I think.... power is backfeeding. His suggestion would likely work but I can't help but think that is a bit of a bandaid solution - no offense intended to John. I feel that the best solution is to fix it right by installing the DRL module or, at the very least, look at a wiring diagram to determine a more appropriate switchable source or remove the "bridge" that backfeeds the power when the headlight switch is "on". It is a complex problem.

I have found that the DRL module on Blue Jean allows only the amber lights, tail lights and the smaller white clearance lights (lower front end) to be on in the first position after "off" (no headlights). This allows the fog lights (switched independently) to do their job without glare from the white headlights while still having clearance lights from behind. Does this make sense?....

Thinking I'm rambling at this point but might be something helpful in there somewhere.

[jessef]

I have found that the DRL module on Blue Jean allows only the amber lights, tail lights and the smaller white clearance lights (lower front end) to be on in the first position after "off" (no headlights). This allows the fog lights (switched independently) to do their job without glare from the white headlights while still having clearance lights from behind. Does this make sense?....

Thinking I'm rambling at this point but might be something helpful in there somewhere.

The Grote DRL module from Canadian Tire/Lordco does just that.

Key position :

Acc / On / Start - Headlights on only (daytime running lights)

Light switch position :

Off - Headlights on only (daytime running lights)
Parking Lights - Parking/marker lights on / Headlights off
All Lights - Headlights on + Parking/marker lights on

[Muzzy]

I have found that any amount of draw on the alternator will lower the revs - thus when you turn lights, rear defrost, etc off the engine revs will pick up. This is most noticeable when in park or neutral as there is no other load on the motor.

Enough to make it increase by 150 to 200 rpm? I do notice a slight increase when the heaters and defrost are turnd off maybe 25-50RPMs at most (that's just a guess) but the big increase is always from the light switch being turned off. I haven't really had time to look into it. I'm hoping to get around it this weekend. So like I said previously I have disconnected the relay and wiring in question. This has stopped the back feeding. So obviously somewhere there is a splice that shouldn't be there. I just need to track it down and remove it.
After my drive home last night I stopped put in Park turned the lights, front and rear heater off and no increase in RPMs I did this a few times and it stayed consistent. But then this morning once I got to work same thing RPMs would increase by 150 to 200 just by turning the lights off. I scratched my head for a bit but had to get to work????
I have been looking at DRL modules from http://www.hamsar.com/drlkits.htm. They have all kinds, some with 2 lights, 4 lights, and Fog light option combinations. I do have a question would it be illegal to setup the "High beams" to come on when switching to the "low beam" setting (so having both high and low on at the same time) but have the high operate at somewhere around 60% output? To help compensate for the lack of illumination from the low beams. I know they are aimed higher, just not sure if it will blind on coming traffic or if I could get a ticket for that. Anyone know?
But John is right. All of our stepvans we manufactor here at work have the DRLs setup to the park brake. Park brake on = lights off, Park brake off = lights on. And I will definetly set it up that way.