Instrument panel – removal for bulbs / bypassing or fixing t

[Billy Smalls]

Hi There

I thought I would write a description of how I bypassed the rheostat on the instrument panel (IP); this is the small black knob on the left hand side of the panel. I believe this is a common problem, as the rheostat is basically a copper contact point that is turned around a ring of copper spring – the copper oxidises and causes problems, it also makes a horrible scratching noise as you turn the knob.

You can also use this method to gain full access to bulb-holders etc.

Okay, mines a 1970 RHD automatic, so I will describe for that. This is a DL model, so a simple single carb. This is for the older ribbon speedo set up.

1. Take off the fuse compartment ‘panel’
2. On the right hand A post, just by the air vent, unscrew black panel by your right knee – 1 self tapped.
3. Remove steering column casing – black plastic, 1 screw on top, 3 screws underneath. I’m not certain this is essential for access, so try without maybe.
4. There are 2 white plastic tubular ‘nuts’ fixing the IP from the rear. 1 top left of IP and 1 bottom right of IP (as you look out windscreen)
5. To unscrew these blind, reach your hand though the fuseboard panel and up behind the IP. And for the RH one, bend the panelling by your right leg (it won’t snap) and reach up behind the IP – they unscrew about half an inch out – don’t forget to unscrew ‘clockwise’ as it were
6. Disconnect the speedo cable – it is top right of the IP (as you look out windscreen) – it is set at an angle, with an outer bezel ring that once unscrewed allows you to pull the speedo cable male part from the IP female part. DON’T BEND THE SPEEDO CABLE TOO MUCH
7. You should now be able to lift the IP forward enough to expose the PCB / innards!!
8. If yours is an auto, then there is a metal ‘plate’ that holds the gear ‘indicator’ cable. There are 2 alloy ‘turning keys’ that once turned 180 degrees, allow you to remove the gear indicator and cable for ease of IP removal
9. You will need to unplug some cable plugs now – so get a marker pen out and mark them up with little symbols / crosses / numbers. On mine there were 4, including 2 that form a sort of yin-yan circle.
10. Now the IP can be pulled out without any obstruction
11. You’ll see the rheostat and my rubbish description of it will become clearer!!!
12. The rheostat slots onto the PCB with 2 spade connectors– though it may feel like it’s secured as the spade connectors are stiff / corroded a bit (you may also see a small pile of copper oxide dust beneath where it sits!!)
13. If you want to utilise the rheostat then it looks like you can take it apart by prising two tiny metal tabs and cleaning it up – personally that can wait, so I simply wired the 2 spade connectors on the PCB together
14. To put it all back together really is the reverse, offer the IP up and:-
15. Plug the sockets back in, starting at the rear for ease – 4 of them in total
16. If auto – slot the gear indicator ‘box’ back into it’s slot and secure with the 2 little ‘wings’
17. Reconnect the speedo cable by reaching round – slot the male part into female and screw the bezel ring to secure (it may have slipped down the cable towards engine – so don’t panic if it’s not there)
18. Reconnect the 2 white plastic tubular ‘nuts’ to secure the IP – will take a moment to work out where they screw on, but not too tricky.
19. Reattach the steering column casing – it may have warped a bit over time, so jiggle it round a bit, but not too much or you’ll snap the lugs along the edges of it where it joins.

I could probably have worded all that better and if I had more time I’d have taken snaps – but my daughter was in the backseat asleep and she woke just as I was re-connecting the speedo

Total time not having done it before – 40 minutes
Tools – medium crosshead, bit of copper wire should you choose to bypass, marker pen

Please do question me on any of this – would like to put some knowledge back into the forum……

Cheers