The Triumph 2000/2500/2.5 Register Forum

I have been searching through the previous topics and there is lots of discussion on the topic over overdrive relays, but not where it is.

I had my overdrive working fine after a new solenoid. Its worked ok for several months, but it has failed again.

I think that it is the relay because I cannot hear anything and with a test buld there is no illumination at the solenoid with the overdrive on, meaning no power is getting to it.

Where is the relay hidden, I can't find it so I am looking in the wrong place. Is it easy to get to? What is the best way t get to it.

Thanks

Jeff

I think you have answered your own question if there's no power getting it.
Most overdrive issues (failure to engage) are caused by poor electrical connections. I've never had the relay fail.
On my Royal Blue Mk1, the overdrive stopped working earlier this year. A quick clean of the two bullet connectors underneath that are quite exposed to dirt / damp, cured it immediately.
The wiring in the car rarely gives problems, unlike the Mk2 which suffers from breaks in the wiring where it passes through the hole on the gear lever.
On the Mk1, the overdrive relay is an aluminium rectangular box about 2" X 1" in size with two legs for the mounting screws, fastened at the front off the offside inner wing above the control unit (regulator). Worth cleaning these connections too.

You're right. I cleaned up the connections to the solenoid and can't hear the relay click or get the solenoid to work, but with what you say Jonny dog I will give this another go to be on the safe side. But looking at the wiring diagram the two relays by the fuse box are not the relay (65) in the manual. Is it the upper or lower relay? The wiring diagram does not suggest these two are the ones due to the colour of the wires and those in may manuals including the blue book.
Maybe just another duff solenoid. What do you think. A types overdrive by the way. I like your royal blue Mk1 if that's the one you brought to the national. Good honest motor.

Jeff

There are from memory relays for the horn which has purple wires, the lights, and the overdrive. It should be relatively easy with the aid of a friend to work out which is which by getting them to listen or even by touch feeling for the 'clunk'. Good luck.

Hi

There are two relays there, I will do what you say. But like I say, none of the wires to either of them are the colours list in all my books.This worrying me a bit because, if I can't hear anything, and both click on test with lights and horn, then which one is overdrive relay? I will try tomorrow when I get a chance. Jeff

The overdrive relay is on the left-hand inner wing, near the washer bottle, just above the inspection lamp sockets.
I've just confirmed on mine by pulling off one of the wires, and the OD doesn't click if the wire is removed.
The colours on mine agree with haynes - White, Brown, Yellow/Purple, Yellow/Green.

That's on an original 1967 car. If yours was not orginally fitted with overdrive of course the relay might be anywhere.



Of the two relays over by the regulator:
The lower is headlight flasher, the upper is horn.

Clifford
I think you are correct! My memory isn't that good! My car didn't have OD when produced and is running a J type, so do not have a relay!

As an aside, i think fitting a relay to a 'J' type overdrive car is a good idea. The 'inrush' current when the overdrive is operated is quite large and I expect well beyond the rating of the gear knob switch. I have had these switches fail in the past, due to (I think) excessive current!

Just a thought really!

Cheers,
Mike.

Clifford Pope wrote: ↑

Fri Nov 24, 2017 4:46 pm

The overdrive relay is on the left-hand inner wing, near the washer bottle, just above the inspection lamp sockets.

That makes sense - the wiring for the overdrive runs on the passenger side, as does the overdrive wiring on the Mk2.
I've only owned my Mk1 for 33 years - its about time I knew where the relay was actually located, instead of thinking it was on the offside inner wing !!