Fuse blows when using overdrive

[MIG Wielder]

Hi all,

When driving or ticking over, my IGN indicator starts to light up on my dash. Flickering but never fully highlighted... Car runs perfectly

Thanks

Hi Colin , Slight misunderstanding on this.
You seem to have 2 separate electrical problems.
This problem is most likely a faulty alternator or its connections. If you don't fancy diving into the internals of the alternator the best solution is a replacement.

as soon as I flick into overdrive (when driving) my 35a fuse blows and I lose indicators, fuel gauge, Rev counter, wipers and heating. I then pull over, replace the fuse and carry on with everything working fine... so long as I don't engage overdrive again.
Thanks

.... and this problem is most likely the wiring into the gearlever.

I've modified my previous note as Mart suggested btw.
Thanks both,
Tony.

[calderfisher]

Happened to me also. Had to raise the gearknob slightly to avoid wires touching gearstick tube, Was also getting a shock as well as a blown fuse.

ATB
Craig

[Edin Dundee]

I'm hugely surprised at the electric shocks, shouldn't happen from 12 volts surely. Is it the solenoid coil discharging to earth? It happens to too many people to be anything else (myself included)?

[Jon Tilson]

The coils in your solenoid act like a mini ignition coil. Hence the bigger than expected shock.
Much worse in the spit if the seat has got damp...

Jonners

[colinwoods]

Hi All,

So... I replaced the alternator with a new one and the red IGN light is no longer on. Car seems peachy. Problem one solved!

However, as for the overdrive, well that's just being pedantic. When I switch the overdrive into action the fuse was still popping but now the overdrive switch does nothing. It's just a dead switch. (I obviously changed the fuse and all instruments are working fine).
So I removed the gear stick knob, removed the gear stick cover and plastic tray and also pulled the carpet up so I could see everything thing from the wire sticking out of the top of the gear stick down to the over drive itself. the wires looked OK but I didn't really know what I was looking for except lose wires (none were found to be lose). I bought a new overdrive switch and gear knob, replaced it. Put it all back together and I'm still getting zero action from my overdrive. Car works fine including all instruments. Just nothing from the overdrive.
I'm guessing I should replace all the wiring from the switch to the overdrive but it might be difficult for me. Or of course maybe the overdrive itself needs replacing?

Any ideas?

Thanks again

[Mahesh]

Is you horn working?,

Even if it is, to my memory it shares a common relay with the overdrive,
might be worth a quick look.

[colinwoods]

Horn works fine...

[Edin Dundee]

**!!%@ grrrr!!!!
I'll start again, bloody hotel crappy wifi arrggh
An original Dolly has no relays, none, zip nada.
Two fuses, that's your lot. This makes fault finding very easy - or very difficult, depending on your experience/point of view.

[80Sprint]

Use a meter to test first you have 12v at the switch and after the switch when operated to find out if the issue is before or after the switch. Then move to the solenoid to check voltage there.

[Mahesh]

Mines had a relay shoved in for some reason, will remove once the car is back, another electrical item on the list.

But as per the guys, according to the repair manual, it's fuse box to overdrive selector, gearstick switch, and then overdrive solenoid.

If you meter the gearstick switch first, it will then guide you as to which way your voltage is missing.

Your 15 mins away from me, but I can't help till after the weekend.

[Jon Tilson]

You mean overdrive inhibitor on the selector mechanism, being pedantic.

Also don't forget the loom connector by the gearbox, the one with the starter loopback. If your reversing lights work then this connector is working. If they dont it may be worth looking at. Power for both is on the same pin....

Jonners

[colinwoods]

Mines had a relay shoved in for some reason, will remove once the car is back, another electrical item on the list.

But as per the guys, according to the repair manual, it's fuse box to overdrive selector, gearstick switch, and then overdrive solenoid.

If you meter the gearstick switch first, it will then guide you as to which way your voltage is missing.

Your 15 mins away from me, but I can't help till after the weekend.

Hi Mahesh

I'd really appreciate your help as electrics are definitely not my bag. I don't even know how to meter the gearstick.
FYI, after changing the Alternator and OD switch I now have no action from the switch at all. It's totally dead. The OF doesn't kick in the fuse wouldnt blow. I swapped the two wires round just to make sure it was plugged in correctly and o get same result.
However! Just today the fuse has blown three times when not even engaging the overdrive (this might be because I plugged my phone charger into my cigarette lighter thingy and maybe that's related?)

So, I'm flummoxed. If you are cool to come round, or I could bring the car to you if easier, that would be great!
I'm also looking to get my rusty sills replaced and will be taking her to 'bodyteq' in Greenwich/deptford. Does anyone have any experience or knowledge about how much it l's likely going to cost me to replace all sills on both sides?

Thanks all. (Let me know what best for you Mahesh)

[Jon Tilson]

I strongly supect that your stick loom has chafed through the holes in the gearstick and is shorting out. The stick loom goes live when you move the lever into the 3rd and 4th side of the gate. If its live and shorting this will blow the fuse....

Your instruments indicators wipers and heater will then all stop working.

You need a new stick loom....anglian triumph do them for about 10 quid...

Fitting is fiddly but doable...

Jonners

[colinwoods]

Thanks Jonners,

By loom you mean the wires going from the OD up through the gear stick shaft and to the actual switch? If so, I'm not sure how I'm going to get my hands in the small hole of the car chassis to the gear box (over drive bit) itself. Looks proper fiddly but I'm determined to crack in and fix it. The cause sounds very plauseable.

Can I not use just normal wiring from the local DIY or halfords or is it a particular wire?

Thanks again!

[Mahesh]

Sorry for not being able to reply, been at stonleigh all day.

I can come over Monday evening, pm me your details.