Allsortz Posted June 4, 2016 Share Posted June 4, 2016 Hi everyone, im in the process of rebuilding an M998 Humvee and getting to the stage where I'm ready for an MOT.. HOWEVER I need to do something with the rear lights as they are in American format ie indicators and brake lights are on same system.. I'm not particularly good with electrics.. So far everything is numbered and connects up with waterproof connectors and I'm reluctant to call any auto electrician who will start chopping into the loom! hopefully other people have dealt with this and any advice would be great fully received! thanks Dan. Quote Link to comment Share on other sites More sharing options...
g0ozs Posted June 4, 2016 Share Posted June 4, 2016 Hi Whereabouts are you located ? possibly if someone knows they are nearby they can be of practical help. I believe the wiring diagrams should be available on line if you know the TM number but I would expect that as long as there are separate brake and indicator bulbs behind the red glass it should be possible to connect a separate indicator in parallel with the indicator bulb socket (which will involve cutting into the wiring close to the lamp cluster) and leave the original bulb out. I guess it is to some extent a matter of originality vs practicality whether you fit something like a landrover indicator alongside the original or look for a military light cluster that includes separate indicator and brake light sections. At one time the French used a lot of US-style light clusters but had separate indicators so a search of the Marmon or Hotchkiss Jeep parts dealers may turn up something suitable. Regards Iain Quote Link to comment Share on other sites More sharing options...
g0ozs Posted June 5, 2016 Share Posted June 5, 2016 (edited) Apologies - finally found a legible diagram for the M997 version online at http://www.kascar.com/Real4WD/manuals/M996-M997-Wiring-Diagrams.pdf - and if yours is similar then the same wires (circuits 22-460 and 22-461 from turn signal switch pins E and C) and bulbs are used for turn signal (T/S) and stop which means that they can't be easily separated. It might be hoped that you could use the separate indicator connections that should be present on the NATO trailer receptacle and use them to control new separate indicator lamps. If it's a standard NATO trailer socket then pins B and J are stop, and pins M and N are separated turn signals. Of course as this is a US vehicle with combined stop and tail lamps, only B and J are connected There are independent indicators (circuits 460 and 461 from turn signal switch pins A and B) at the front end of the vehicle: and I think the least bad options may be to run new wires from them to the back for independent new indicators It may be wise to use LED lamps for the new rear indicators to minimise the additional current in circuits 460 and 461. This leaves the problem of the rear brake and indicators being combined. The brake and indicator unit outputs are combined somehow in the main lamp switch and the input D to the rear indicator part of the turn switch appears to be the brake light control signal. I think the circuits 22-460 and 22-461 are connected to the brake light switch if centred and one side to the appropriate indicator output if the turn signal is in use ? If so I suspect that one side will flash and the other will be on all the time, if brakes and indicator are applied together ? If that is the case, then simply feeding the circuits 22-460 and 22-461 directly from circuit 22 without going through the turn switch should work to get working brake lights with no flashing when the indicators are on. Physically I don't know how easy the back of the turn switch is to get at, if you need to do this. Having written the above, I guess it is only necessary if the indicators will be tested with brakes applied, or vice-versa. I am an electronic engineer (so can read circuit diagrams) but not an auto-electrician - hopefully the above extracts are enough to guide an auto-electrician so that they can avoid either creating a complete new indicator and brake harness or cutting into the original one. Regards Iain Edited June 5, 2016 by g0ozs Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted June 5, 2016 Share Posted June 5, 2016 Wiring diagrams and other useful information for M998A here:- http://www.hummerknowledgebase.com/HMMWV.html Electrics here:- http://www.hummerknowledgebase.com/electric/index0.html 1 Quote Link to comment Share on other sites More sharing options...
m109a3uk Posted June 5, 2016 Share Posted June 5, 2016 Nice truck where did it come in from? Fancy one myself! Hi everyone, im in the process of rebuilding an M998 Humvee and getting to the stage where I'm ready for an MOT.. HOWEVER I need to do something with the rear lights as they are in American format ie indicators and brake lights are on same system.. I'm not particularly good with electrics.. So far everything is numbered and connects up with waterproof connectors and I'm reluctant to call any auto electrician who will start chopping into the loom! hopefully other people have dealt with this and any advice would be great fully received! thanks Dan. [ATTACH=CONFIG]115753[/ATTACH] Quote Link to comment Share on other sites More sharing options...
datadawg Posted June 7, 2016 Share Posted June 7, 2016 Hi everyone, im in the process of rebuilding an M998 Humvee and getting to the stage where I'm ready for an MOT.. HOWEVER I need to do something with the rear lights as they are in American format ie indicators and brake lights are on same system.. I'm not particularly good with electrics.. So far everything is numbered and connects up with waterproof connectors and I'm reluctant to call any auto electrician who will start chopping into the loom! hopefully other people have dealt with this and any advice would be great fully received! thanks Dan. [ATTACH=CONFIG]115753[/ATTACH] Dan, not sure if you have resolved your problem, but if not, try posting on steel soldiers forum. It's the US equivalent of this site, and there are a lot of HUMVEES in circulation here now, so I'd expect a lot more people are familiar with them on that site. Quote Link to comment Share on other sites More sharing options...
TooTallMike Posted June 7, 2016 Share Posted June 7, 2016 Hi, Having done similar wiring changes to various M-series vehicles I can tell you it will be necessary to either modify the wiring loom or disconnect sections and bypass them. Modifying is much neater. The entire loom is designed to operate the lighting the American way so the functions are combined at source and therefore have to be separated from there. If you want to modify the existing loom you will need to identify 'spare' circuits running to the corners such as those for blackout/convoy lighting which can be adopted for the functions you need to separate out. Regards - MG Quote Link to comment Share on other sites More sharing options...
Allsortz Posted June 9, 2016 Author Share Posted June 9, 2016 Hey guys, thanks so much for the info, especially the wiring diagrams.. ! I think I'm gonna either try to run wires from the front indicators or rig up some device to connect to my trailer socket.. I have found a guy who has done similar mods before but getting him to work on my truck is proving difficult at present but I'll keep you posted on the progress.. I have had a good look on STeel Soldiers site but as this is a truely European problem have not had much luck there.. TBH I only want to get it through its MOT and then I'd be quite happy running with the US setup.. i have set the truck up with LED lights front and rear so the voltage isn't an issue.. Though I left two marker lights with normal bulbs as this helps the LEDs work properly so I have been told.. Seemed to work too with Std flasher unit. I bought the the truck a year ago from EBay, it's previously been used for film work on world war Z Green Zone and Sniper apparently! Just fitted a Rhino spare carrier and now checking the hubs. I'll post a few more pics when I'm done.. Quote Link to comment Share on other sites More sharing options...
Allsortz Posted June 9, 2016 Author Share Posted June 9, 2016 Quote Link to comment Share on other sites More sharing options...
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