17 replies to this topic

[blue cube]

a resister would do the trick afaik right??

im not an electronics guru, so i dont really know what do stick in both sides,
but im sure alot of us have the same problem, and im sure a quick drive down
to radio shack can fix it

so does anyone know or can anyone figure out what kind of resister is needed
to bridge the stock line???

[Serge]

5th time I'm posting this... really need to make a FAQ.

You can add a dummy load to compensate for the lower current drain. I would use a DMM in series to measure how many amps are drawn with a regular halogen and then with the HIDs. Subtract the two and you will know the amount extra current you need to drain.

Using the formula R = V/I; where R = resistance we want, V = voltage of the circuit (12V), I = current drain.

So given a halogen bulb drew 4.5 amps (55W @ 12V, 55/12 = 4.5834) and we'll say a HID ballast draws 2.9 amps (35W @ 12V, 35/12 = 9.167), the difference is 1.6 amps.

R = 12/1.6 = 7.5ohms. You'll need a large 7.5 ohm resistor, atleast 20 watts.

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...item=7955610380 <-- this might suffice.

[maiku]

18W 7.5ohm resistor?
holy moly
thats huge

i thought it shouldn't bring up the bulb failure light
lots of S70's here have hids (look NW) and they don't have the warning

[Serge]

18W 7.5ohm resistor?
holy moly
thats huge

i thought it shouldn't bring up the bulb failure light
lots of S70's here have hids (look NW) and they don't have the warning

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...item=7955610380 <-- 6 ohm 50 watt.

[Slater]

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...item=7955610380 <-- 6 ohm 50 watt.

Man even that is gonna get hot as heel.

Easiest way is to remove the bulb in the cluster.

Second easiest way is to follow these instructions:

http://www.xenonvalot.com/xenonfixvolvo.html

- Slater

[Serge]

Man even that is gonna get hot as heel.

Easiest way is to remove the bulb in the cluster.

Second easiest way is to follow these instructions:

http://www.xenonvalot.com/xenonfixvolvo.html

- Slater

It's rated for 50 watts. Pulling 20 isn't going to make it super hot. Plus, if you mount it right there are no issues.

There is no fix like the one on the xenonvalot site for P1s.

[Slater]

There is no fix like the one on the xenonvalot site for P1s.

You sure about that? P1s have a CEM too, just in a different spot. It HAS to work the same way with the shunts. May be as simple as finding the right one. That artucle gives the required resistance change - that's all the info you need.

- Slater

[Serge]

You sure about that? P1s have a CEM too, just in a different spot. It HAS to work the same way with the shunts. May be as simple as finding the right one. That artucle gives the required resistance change - that's all the info you need.

- Slater

Oh P1s have it. Just not in the same way P2s have it.

[blue cube]

5th time I'm posting this... really need to make a FAQ.

You can add a dummy load to compensate for the lower current drain. I would use a DMM in series to measure how many amps are drawn with a regular halogen and then with the HIDs. Subtract the two and you will know the amount extra current you need to drain.

Using the formula R = V/I; where R = resistance we want, V = voltage of the circuit (12V), I = current drain.

So given a halogen bulb drew 4.5 amps (55W @ 12V, 55/12 = 4.5834) and we'll say a HID ballast draws 2.9 amps (35W @ 12V, 35/12 = 9.167), the difference is 1.6 amps.

R = 12/1.6 = 7.5ohms. You'll need a large 7.5 ohm resistor, atleast 20 watts.

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...item=7955610380  <-- this might suffice.

thanks man
sorry, didnt mean to piss you off.

[Serge]

thanks man
sorry, didnt mean to piss you off.

Don't worry about it

Just more insentive for me to make a FAQ.

[theunderlord]

I know of 4 people that have HID's... none of us have the idiot light. Either on 70 series or 850. So... that leads me to think that you wired them up differently...

am i wrong to think this guys ?

[Zappo]

I have HIDs in both headlights and fogs. I have never had a failure light when both sides are working. If I disconnect one side, the light will come on just like it is suppose to.

I am not sure how you can wire it wrong. Only 2 wires, and if you reverse them, it doesn't work. At least that is what happened to me. I know on the 850's the light is triggered if the load between the left and right sides of the car is off by a certain amount or more. If you only get the failure light when you turn on the headlights and both headlights come on, I would test to see how much power each headlight was using.

[blue cube]

im running another wiring harness with relay
thats why mine is coming on..

[beachnut]

I know of 4 people that have HID's...  none of us have the idiot light.

Make that 5 people ... easiest way to permantly fix the issue.

[Serge]

im running another wiring harness with relay
thats why mine is coming on..

Yeah, the relay draws very little. You could hook up the ballast directly w/o using a relay.

[blue cube]

im only using it beacuse it came with the kit

[drPheta]

I've been told that running the ballast w/o a relay could cause damage to it because of electrical spikes occuring during the switching on/off of the ballast directly with the 9006/9005/h1/etc harness.

This is probably why some of us are getting the idiot light, since we're all wiring one of a few ways. Some of which cause the load to be drawn differently compared stock halogen. (due to the recommended use of an 1N400d diode with a relay to prevent spiking)

This is where I've read up on HID lights for a long time
http://faqlight.carpassion.info/

From the site
How can I ensure that I do not fry my cars internal headlight harness?

During normal HID operation, you use only 42 watts (35W to run the bulb plus 7W in heat losses in ballast) instead of the 55 watts that the halogen bulb uses, which is less, but, during HID cold startup, and for the first several seconds during warmup, the HID system can draw up to triple the normal operating power to run the ignitor circuit during that time. As the bulb warms up, the current draw tapers down to the normal running level. By powering the ballast through a relay straight from the battery to HID ballast, the heavy load is removed from stock headlight curcuit. Triggering the relay only requires 0.1 amps, so stock headlamp curcuit has no problem powering that. A relay is just a remotely mounted heavy duty switch, and the trigger power that goes to it just draws a small amount of current through the headlight switch to run an electromagnet that mechanically closes the contacts inside the relay which in turn hooks battery power strait to HID ballast power terminal. This insures that you wont ever overdrive the ratings of your vehicle's harness.

and the image below and info can be found here on how to wire up the HID
http://faqlight.carpassion.info/headlamp-harness.html

Edited by drPheta, 28 April 2005 - 02:24 PM.

[Serge]

That's a good point. I completely forgot that the normal operating current of the ballast is different from start-up. I just suggest using a relay and a load resistor.

As for the diode, it's pretty important to have to prevent reverse-current damage from the relay. However, I don't think there is anything super sensitive on the other side. But good practice is to use a diode.