Where to mount DDM HID Ballast to prevent Tachometer jump?

[DarienFalks]

My HIDs cause my tachometer to jump when I switch from high beams to low. Right now they are zipped tied to the back of the headlight housings. Is there a better mounting point where they wont interfere with he cars electrics?

Thanks!

[SW530]

I doubt its the physical proximity to your cam sensors or the ECU. It could be either the power or ground is tapped into something it shouldn't be instead of having its' own circuit. Investigate the wiring.. You could even build a cheap RC or LC filter if you find you're only tapped into the stock headlight circuit, but I doubt it. We're using 55w HID's (and separate fogs) on both an E-34 and E-30 with zero issues.

[DarienFalks]

I doubt its the physical proximity to your cam sensors or the ECU. It could be either the power or ground is tapped into something it shouldn't be instead of having its' own circuit. Investigate the wiring.. You could even build a cheap RC or LC filter if you find you're only tapped into the stock headlight circuit, but I doubt it. We're using 55w HID's (and separate fogs) on both an E-34 and E-30 with zero issues.

I thought maybe the DDM ballast were not shielded very well and were putting out too much EMI? Still they are not close to the LKM and I am using the 55w 4500Ks for lows and 35w 3000k for fogs.

[Hofmeister]

I'm having the same issues. I have my fogs mounted in the bumper and shielded with foil. The lows I haven't touched. Its a sometimes problem too.

[slocar]

If you're not running a harness with a relay for them, do that first ...

I had issues with my e36 where all the gauges would drop to zero then spring back to life when I turned on my HIDs ... the wiring harness took that issue away and has been issue free for 5 years now.

[Binjammin]

This is pretty well covered. Mount them low and outside the body of the car if possible.

Not outside the fender, but outside the frame horn.

[Tre0Tre34]

I want to say someone had mounted their ballasts inside the framerails behind the bumper cover.

No personal experience with hids on an e34 though.

[sse34]

Good quality ballasts fix this issue to lol

[SW530]

I thought maybe the DDM ballast were not shielded very well and were putting out too much EMI? Still they are not close to the LKM and I am using the 55w 4500Ks for lows and 35w 3000k for fogs.

Really, first make sure they're properly wired. This should include either their own power feed or a relay through a stock power feed. The grounds should be bare metal clean and once connected spray with a clear coat whatever.. you probably have a can laying around. If that doesn't do it (It will), ground the exterior of the ballast body. Wrapping them in foil or even in 18g tin won't do a thing if the foil/tin isn't then grounded. But since any decent ballasts come in metal cases. (http://www.amazon.com/gp/product/B00FC229Y6/ref=wms_ohs_product?ie=UTF8&psc=1). just ground them. The connections must be clean, soldered unless using posi-locks (http://www.amazon.com/Posi-Lock-Connectors-Superier-In-Line-Tightening/dp/B009RPFMP2/ref=sr_1_4?ie=UTF8&qid=1406268124&sr=8-4&keywords=posi-locks) (all but the very best crimp on connectors are garbage and even the best isn't as good as posi-locks) They sell weather sealed posi-locks too. A

(http://www.amazon.com/Posi-Products-Posi-Seal-Weathertite-Connectors-4-pack/dp/B00HTR29JW/ref=sr_1_19?ie=UTF8&qid=1406268459&sr=8-19&keywords=posi+products)Add some of this silicone tape to your gear (http://www.amazon.com/gp/product/B00BSXAH06/ref=wms_ohs_product?ie=UTF8&psc=1) too.. this was originally made for the military. We used it over 25 years ago to seal antenna connections against the weather. Stretch it around a connection and let the sun or engine heat fuse it together. Wonderful stuff. Hams use it too. They say it seals leaky hoses.. dunno about that, but it is good stuff.


Take your time, wire them right, mount the ballasts so they don't jiggle around, some people actually lay them inside the headlight buckets.. and your HID's will last forever and not interfere. We have them on four of our cars (the longest one going on 8 years) and I've put them on that many more for family/friends.. usually after they've installed them themselves and had major issues. I've seen some horror.. wires not even twisted together taped up.. ballasts hanging and almost hitting the ground, and worse.

[SwissCheeseHead]

Good quality ballasts fix this issue to lol

Was just going to say that. I had DDMs for about 6 months before the tossed them and went with TRS. They have a lifetime warranty sure, but the ballasts spent more time in transit (getting sent back and forth for said warranty) than on the car. Mine never fired the bulbs. Spend some extra money and get good ballasts.

[djb2]

Posi-locks aren't as good as a real crimp. They might produce a better typical result than the cheapest crimps in the hand of a beginner, but to get a good crimp you need enough pressure to deform the wire and create spring pressure in the crimp terminal. That usually requires a good crimp tool. In some cases a reliable connection can be made by pressing a solid wire into a deep groove 'V' terminal, but that usually requires matching the terminal to the wire diameter and insulation type.

Wrapping ungrounded aluminum foil around an object will cut the high-frequency impulse noise. But in this case it's unlikely that high frequency noise is the problem. It's most likely a low-frequency current surge, or even just a voltage drop. Look for bad grounds, or bad placement of the power tap.

[SW530]

Posi-locks aren't as good as a real crimp. They might produce a better typical result than the cheapest crimps in the hand of a beginner, but to get a good crimp you need enough pressure to deform the wire and create spring pressure in the crimp terminal. That usually requires a good crimp tool. In some cases a reliable connection can be made by pressing a solid wire into a deep groove 'V' terminal, but that usually requires matching the terminal to the wire diameter and insulation type.

Wrapping ungrounded aluminum foil around an object will cut the high-frequency impulse noise. But in this case it's unlikely that high frequency noise is the problem. It's most likely a low-frequency current surge, or even just a voltage drop. Look for bad grounds, or bad placement of the power tap.

1. The problem being a $10 set of combination crimpers, wire cutters, strippers aren't going to do the job.. and a real crimp tool is beyond what most are going to spend(not to mention good crimps).. if they even know one existed. And even with a good crimp, even with soldering, you have a press fit connection (crimp on male/female ends) that on something that vibrates and has temp extremes will move back and forth which affects long term reliability. This is less of a problem with a posi-lock especially if you lock-tite the threads.

2. No might about it. Virtually anyone who can read the directions will get a 'good' long term connection using them.

3. Or amplify it. This is why any good tempest shielding's weave and coverage is dependent on the desired suppressed freqs. But agreed, this isn't it.

4. Yup, absolutely.. right on the money. But both require good connections and considering the OP's question and probably his original wiring job.. wanna bet on posi-locks or his crimping skills? ;o)


In all seriousness I agree posi-locks aren't the best solution. But all considered I do think the OP could use them effectively and would have a much less chance of making a workable fix. I've spent many long tedious hours building custom looms with mil-spec connectors.. but for a 20 year old project car.. I'm not spending that much time. Wait.. not true. I went this route with my true love.. but not the other 10+ I put HID's on. And you can re-use posi-locks..

[JesterMX6]

i have DDM ballasts. I have one mounted on my strut tower and the other zip tied to the front rad support.. zero problems when using them.

rad support, top of the picture

https://farm9.staticflickr.com/8495/8328944812_9df38d2c23_c.jpg (https://flic.kr/p/dG127L)
deja vu radiator installed (https://flic.kr/p/dG127L) by jestermx6 (https://www.flickr.com/people//), on Flickr

strut tower, bottom of this picture.

https://farm8.staticflickr.com/7048/6825166400_358a563959_c.jpg (https://flic.kr/p/bp7LbL)
engine bay 2012.03.10 (https://flic.kr/p/bp7LbL) by jestermx6 (https://www.flickr.com/people//), on Flickr

[Binjammin]

i have DDM ballasts. I have one mounted on my strut tower and the other zip tied to the front rad support.. zero problems when using them.

rad support, top of the picture

https://farm9.staticflickr.com/8495/8328944812_9df38d2c23_c.jpg (https://flic.kr/p/dG127L)
deja vu radiator installed (https://flic.kr/p/dG127L) by jestermx6 (https://www.flickr.com/people//), on Flickr

strut tower, bottom of this picture.

https://farm8.staticflickr.com/7048/6825166400_358a563959_c.jpg (https://flic.kr/p/bp7LbL)
engine bay 2012.03.10 (https://flic.kr/p/bp7LbL) by jestermx6 (https://www.flickr.com/people//), on Flickr

Those are the old ones, the new digital ballasts are the "slim" ones. Jesus, I don't think they've sold those since like 07... and I don't think DDM made them back then anyway.

[JesterMX6]

i got mine in 2010. didn't realize they had a newer model. mine are still working great and i've had zero issues. not sure if they're manufactured by DDM themselves, but they get the job done with no errors and no interference.

[Binjammin]

i got mine in 2010. didn't realize they had a newer model. mine are still working great and i've had zero issues. not sure if they're manufactured by DDM themselves, but they get the job done with no errors and no interference.

The point I was getting at was that I think the problems are with the slim ballasts.

[JesterMX6]

yeah i didnt realize that.

[DarienFalks]

Really, first make sure they're properly wired. This should include either their own power feed or a relay through a stock power feed. The grounds should be bare metal clean and once connected spray with a clear coat whatever.. you probably have a can laying around. If that doesn't do it (It will), ground the exterior of the ballast body. Wrapping them in foil or even in 18g tin won't do a thing if the foil/tin isn't then grounded. But since any decent ballasts come in metal cases. (http://www.amazon.com/gp/product/B00FC229Y6/ref=wms_ohs_product?ie=UTF8&psc=1). just ground them. The connections must be clean, soldered unless using posi-locks (http://www.amazon.com/Posi-Lock-Connectors-Superier-In-Line-Tightening/dp/B009RPFMP2/ref=sr_1_4?ie=UTF8&qid=1406268124&sr=8-4&keywords=posi-locks) (all but the very best crimp on connectors are garbage and even the best isn't as good as posi-locks) They sell weather sealed posi-locks too. A (http://www.amazon.com/Posi-Products-Posi-Seal-Weathertite-Connectors-4-pack/dp/B00HTR29JW/ref=sr_1_19?ie=UTF8&qid=1406268459&sr=8-19&keywords=posi+products)

This is my first HID install, so I'm very noobish to them. I zipped tied the lows to the rad support and the fogs are zip tied in the lower part of the bumper. I did not ground anything, I simply plugged and played these bad boys. Let me get some pics up here of my ghetto mounting on my lunch or after work.

[sea6speed]

Pics would be good. The ballasts DDM pictures now on their website look to be completely different than the old kits from a few years ago. I had good luck with those at the time, but I've been hesitant to try the new style (slim/digital) ones.