Want to change the H3 from 55 to 130 w
 

I would like everyones opinion on what problems they think I will get by changing my H3 from the existing 55 to 130w you need to remember that our cars have glass lights and can stand a lot more heat then the plastic ones. In fact the pack say the bulbs are not suitiable for the plastic lights. I was going to put in two relays to do the switching so the standard wiring harness doesn't take the load.
By the way forgot my maths how many amps does a 130w light draw at 12 volts.
Tony

Looks like you had a good trip.:) I have had 100W in the high beams on mine for 4 years now, no trouble. You just have to change the relay from the 8 amp to a larger one to handle the extra amps. I swapped the 8A for a 30A that plugs in the fuse box OK. This relay will handle the 10.8A that each 130W light will pull.

I don't know if the reflector is metal or plastic, but I have had seen any thing that would suggest that they are being affected.

Harvey.;)

Tony, (Nice to have a name to address.)

You are looking at a standing current of say 9.3 Amps with the engine running and 10.8 Amps engine stopped.

However in respect of switching the lights, you are involved with another important issue, i.e. inrush current. When a lamp is cold, the filament resistance is very low and this results in a very high current at switch on. Any contact involved is subject to this excessive inrush current.

I would suggest installing the lamps and observe if they are bright, and or measure voltage at the lamps. The existing wiring could very well prove adequate and all satisfactory. Do not worry about possible heating of the wiring if there is only a small voltage drop.

The OEM relay will have been conservatively rated and could very well put up with the extra load. If cost is a factor, try it for a period. :)

Merry Christmas, Trevor.

So you reckon, its OK for him to run the 21.6 amps through the standard relay, "to see if it will put up with it".
The relay won't be hard to find, it will be the one that is smoking and turning a crisp colour.:eek:

Harvey.;)

Thanks guys its good to get some sound advise on this job. I travel into the desert in Australia a lot and a dead car can mean a dead me so I think I will change the relay now. Which one is it I have to change as I thought there was one for the left and one for the right side.
Tony

I got off my a__ and went and had a look there are two relays on the side of the fuse box "Relay Head RF" and "Relay head LH". As well there is one marked "Relay 8 Head". I looked at all of them and could not find a amp rating on any of them so I will just replace al three with higher rating. What I did notice was that the book said that fuses 24,25 and 26 on some cars have 5 amps higher rating so I will change them as well to play safe.
Its a bit hard to go out and work on the car at them moment as the temp has hit 41 c in the shade they say we may see 46-48 this summer.
Tony

Should have said which relay. The lows have a relay for each one. The highs have the one, R8 front row.

Really if you want to run 130W, I would leave the R8 relay, and fit a Bosch 30A relay to each lights high, out near the lights. As they are going to be on for long periods of time. Just check the bulb plugs every now and again, to make sure they aren't melting. You can get holder plugs with heat resistant wire, that won't melt so easy.

Matt probably knows what to use.

Harvey.;)

In the opinion of one who claims to know more about relays than I do. :rolleyes:
Ex Owner, managing director, systems designer. Relays (NZ) Pty. Ltd. Associated with Relays Pty. Ltd., Melbourne.

Lights installed replaced the the fuses re lights from 15 to 25 figured it would be safe. Couldn't find any relays so I will go with the existing ones for a while as Trevor suggest so we will find out if it was a bad move.
My latest question is that I mesured the voltage at the battery at 12.1V then with old bulbs drop to 11.7v then changed to new ones voltage then 11.4 v. This was done with out the engine running so my guess it will be worst case. When engine is running the voltage is about 13.5V at battery so I don't think the .7v drop is that big a deal.
What do you guys think? They make a great difference to the amount of light. I had tried driving lights but if I hit a Roo the light goes into the body and will damge the car, so better to keep the front clear.
Tony

Tony,

Note that the left and right relays switch BOTH high and low lamps. i.e. the high lamps are controlled via TWO relays. Thus separate circuits are provided for the low lamps on the grounds of safety. The R8 relay provides secondary switching of the high lamps for full beam. RL and RR will normally switch up to 9.58 amps each and R8 10.8 amps using 55 and 65 watt lamps as specified. I am confident that the OEM relays will have a 20 amp rating.

My suggestion was that you first test the system with the higher wattage bulbs, without involving your self in a lot of work. If heat did not prove a problem, you could then tackle any voltage drop issues.

The OEM circuitry is one hell of a mess and is poorly deigned. e.g. The lighting switch carries full load currents and there are long cable runs. If you want to finally have the best of systems, go with Harvey's suggestion of direct connections via slave relays. I am sure you will know to fuse the circuits separately, close to the supply point. Nasty accident here recently, when a car hit a post and caught fire.

All the best with the project, Trevor.

I have been in a car when all the lights died and near hit a tree so I fugured that I might put a relay on each high beam that way if there is a problem I would only lose one. Now that you tell me it all goes throught the switch I will change them for sure as as the higher amps may burn out some other parts. Thank for your help guys.
Tony

Tony,

You do nat have to change any other parts. If you put in directly connected slave relays for the high beams, you will have removed this load from the lighting switch and associated wiring. You will then have an excellent arrangement. The low beams are always on and are controlled independently by way of safety, as I have previously mentioned.

Do you use different bulbs than us because over here the H3's are our FOG lights.

We don't have the fogs Dave,. H3 on both 55W lows, 65W highs. I use 65W lows, 100W highs, a bit better.

Harvey.;)

I have an ex JDM, which has both fog lights and high and low beam.