tr7triumph.com

Hello Everyone,

I have a headlight in my TR7 that will only go up. I

I have a collection of used headlight motors, I was wondering how is the best way to bench test them.

Thanks
Terry

Can't answer directly, just be careful of the fingers testing in situ. There are diodes and things beyond me in the control. However, have you checked and cleaned the connectors in the engine bay behind the headlights. I think there is power to lift and power to lower and if one of the contacts is bad all sorts of things can happen. Suggest first moves are to break, clean and remake the two plug in connectors behind the headlight, check and clean the earth adjacent and as a next move take the switch in the dash apart and clean it. Once you are sure all this is OK progress with more forensic methods which others will advise.

All my headlight problems have been caused by dirty contact in the plugs in the engine bay , just behind the lights. Both the 7 & the 8 have played most of their tricks over the last 15 years. Look for a problem there before taking things off.

Hasbeen

Agree with Hasbeen, almost all headlight problems are caused by dirty/bad connections, that is always your first go to solution. Check and clean the plugs behind each headlight in the engine bay and the earth connections on top of the chassis rails.
Another common problem area is inside the main light switch which gets a build up of green gunge but can be easily taken apart and cleaned.

Someone posted how to make up a bench test harness some time back, I have the pictures so will add them to MyDrive and put a link here.
.............................................

try this:-

https://drive.google.com/file/d/1hziHnE ... sp=sharing

The red connectors behind the headlights power the motors.

Don’t be tempted to put your fingers under the headlight pods to assist them unless you want to lose a finger or two. Disconnect the red connectors before manually raising or lowering them.

The red connector powers the motor but the two single wires control up/down I believe.

One of the jobs still left to do for my '76 car.
My plan is to connect the bare lift motors into the wiring of one of my two running cars and see what happens.
I will probably fit the lever arm to the axle, as this will make it easier to judge the action.

dursleyman wrote:Another common problem area is inside the main light switch which gets a build up of green gunge but can be easily taken apart and cleaned.

When I take the car out or open the garage, I raise the headlights on the headlight switch, then the flasher stalk and turn on the rear fog lights to scrape off the switches’ oxidation. The fog light bulb contacts are the worst, having to be cleaned up every 6 months. (I haven’t driven it in fog for 20 years!)