1985 Turbo Esprit - replacement relay for headlamp lift motors

[jdfish]

One of the original relays has gone missing. Does anyone know of a correct replacement relay?

The other relay is a 5 pin but it seems to have a diode symbol on it.

[snowrx]

Your schematic looks like a most common changeover relay, but the pins should be marked 87 and 87a. I think the "diode" designation is just indicating movement or the normal position of the contacts.

Some vendors will label a relay that energizes both contacts as 87 and 87 rather than 87 and 87b. 

The wiring diagram for the headlight lift motors shows a changeover style, fitted to every car made.

The headlamp main and dip beams use the other style, connecting 30 to both 87's.

[jdfish]

Thomas,

Thanks for the clarification and details. You are correct that the two 87 contacts are in fact  87 and 87a.

I have changeover relays and when i insert one into the missing relay space the headlight pods do the "up down, up down" cycle repeatedly. time to look for a bad ground??

 

[snowrx]

The motors, like a windscreen wiper, should control the "park" position, and thus the cycling, of the pods up or down by way of the contacts in the gearcase. I would expect one side or the other to have an issue if it was a problem there. Unless the motors or pods had been removed or modified changing the geometry of the stop point. 

Not sure what could cause both to be  popping up / down,  possibly  intermittent power from the light switch or flash circuit, or as you mention an intermittent ground on that circuit?

The service notes have several pages in the wiring diagram for the headlight lift, and a search of this forum or LotusTalk will find lots of posts about how this TR-7 derived system works (or doesn't)  Bear in mind later (Stevens?) cars used different motors and some sort of module, so ignore those threads.

[snowrx]

Individual motors may coast past their park point, due to slop in the armature, lack of weight in the pod, or iffy contacts in the internal switches, but if both are doing it, and it came on simultaneously, the plot thickens. 

http://www.google.be/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCIQFjAAahUKEwjGg6TdtKHGAhWDhywKHZMnAV4&url=http%3A%2F%2Fwww.wedgeneering.co.uk%2Fimages%2FLucas%20Pod%20Motor%20Strip.ppt&ei=1AGHVcbJD4OPsgGTz4TwBQ&usg=AFQjCNH6Wv1-3j-vaEHRr5ZvuHdSDM7bTg&sig2=NAtdzSPGPzBuvvHbfVqBag&bvm=bv.96339352,d.bGg

 

https://www.thelotusforums.com/forums/search/?&q= motor headlamp switch&page=2&search_and_or=and&sortby=newest

I'm not sure how a bad diode presents symptoms, but at a last resort they are cheap to swap if you have the motors apart for cleaning. 

TR7HeadlightMotorOperation.docx

[jdfish]

Last week I installed refurbished pod motors from SJ Sportscars and they run fine. Last night i "borrowed" the relay for the rear heated screen and installed in the missing relay slot ....no luck, then checked the fuses in the panel to the left of the steering wheel and found one that had blown. Replaced it and the pods work fine now. So happy to have this sorted, thanks Thomas.