Carpokes

Just confirmed with a multimeter on my car. Pin B1 is dead with the headlights off, and gets "12 volts" voltage (positive) when the headlights are turned on. The actual voltage level on B1 is controlled by the dash light dimmer, with a high of 11.5 and a low of 10.8 volts (with the engine off). I noticed before when developing my cluster LED kit that the power output from the dimmer is generally a volt or more less than the battery voltage, at least on my car.

Thanks Tom

I tested the pins with multimeter and neither is getting 12 volts, key on, headlights on. Headlight switch is brand new.

Going to splice in 12 volts to both and call it a day. Just need to get a resistor to dim the new led bulb for fan knob as it’s a tad too bright

Appreciate your help!!

kwest3904@gmail.com wrote: Tue Jan 23, 2024 7:50 pm Thanks Tom

I tested the pins with multimeter and neither is getting 12 volts, key on, headlights on. Headlight switch is brand new.

Going to splice in 12 volts to both and call it a day. Just need to get a resistor to dim the new led bulb for fan knob as it’s a tad too bright

Appreciate your help!!

When you say both -- not sure what you mean? I think if you send 12volts to B1, that would do it to keep the climate control lights on all the time. If your instrument cluster lights are working/dimming, you can tap into the wire that drives those lights and send it to B1 so that the CC unit light work as intended... I can look up which wire that is if interested. All the dimmable lights are 'supposed' to carry that same signal.

ah, you are correct. Per your replies prior:
All lights except fan knob
B1: 12v
B5: ground

Fan knob light
B1: 12v
C2: Ground

I found pinouts for the headlight switch, will make sure plugged in correctly, test it, etc.




If cannot find any issue with headlight switch, I will then confirm at HVAC connectors that there is ground to B5 and C2 and if not if getting 12v at B1. As last resort will direct wire negative to B5 & C2 and/or 12v to B1

I'd suspect the b1 power wire before the grounds, only because there are multiple grounds that work to power those lights and it seems unlikely they they are all bad yet the climate control unit still works (just with no lights). If you test b1 with a multimeter, it should jump to almost 12v when you turn the lights on, and go up and down a bit when you adjust the dimmer. If that checks out, then I'd pull the cover off the back of the unit and see it there is an obvious solder joint crack on the B1 terminal. If you don't get power on B1, but the instrument cluster lights still work and can be dimmed, then pretty much the only possibility is that that particular wire of the harness, or some connection point in it, is broken/disconnected. That signal from the dimmer branches out to several places under the dash (I.e., everything that dims with the dimmer dial). So, rather than hunt down the break in your harness, or hardwire 12 volts to B1, you can just tap into that signal somewhere else (like where it goes into the cluster) and connect that to the wire going to B1, if that makes sense. That way everything would work as designed.

Great idea! THANKS!

Succes
Not sure why but no power to B1
Spliced in direct to it

kwest3904@gmail.com wrote: Sat Jan 27, 2024 10:52 am Succes
Not sure why but no power to B1
Spliced in direct to it

Awesome, did you find a post-dimmer light signal to use?

Tom wrote: Sat Jan 27, 2024 11:07 am

kwest3904@gmail.com wrote: Sat Jan 27, 2024 10:52 am Succes
Not sure why but no power to B1
Spliced in direct to it

Awesome, did you find a post-dimmer light signal to use?

No, just ran to accessory +
Other than fan knob bulb (replaced with LED) they’re pretty dim even at full voltage. Need to get resistor on the fan bulb though as it’s a tad bright.

I'm not sure how much resistance you'd need to dim that bulb to your liking. If not much, then be careful with the wattage rating of the resistor. If that bulb is, say, a 2 watt bulb, you'd fry a quarter watt resistor unless it supplies enough resistance itself to bring the circuit under a quarter watt. I don't really have any idea if you'll need a couple ohms or a couple hundred. I'm thinking it would be less effort/risk, with a more factory result, just to connect the 12v dimmer signal to B1 on the CC unit. You can get at the 12v dimmer signal by tapping in to the grey/blue wire going to Pin 17 of the "C" edge connector on the instrument cluster (on the oil pressure/volt meter side of the cluster). Maybe when you install the 911-style gauge kit. Here's a picture of that wire. You can see I've already tapped into mine, to have the radio lights dim with the dash...