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multiple instrument cluster issues - jamespi - 03 Aug 2013


I think I might have a bad connector or bad earth somewhere as not much of my instrument cluster actually works.

I replaced the fuel sender but the fuel gauge sits at zero all the time. The fuel warning light is not lit up. I did have to clean a lot of the bulb holders to get the lights to light up, but I don't think I tested all the bulbs.

Sometimes when I first put the ignition on my dash clock flickers on and off randomly.

The temperature gauge was working fine for a couple of weeks but last night the needle was just hanging straight down to the floor and now doesn't move.

The voltmeter works, but registers 8 - 10 volts with the engine off and 11 -13 with it running. When i put a handheld voltmeter on the battery it registers ~12 when off and just under 14 with the alternator running. I've just ordered a new alternator belt as it slips a lot and looks pretty knackered. The alternator was a recon from a Renault Espace (~105 amps?) that was fitted a year or two ago.

The odometer goes round but the speedo spear just sits at zero.

The tachometer either registers way too high or thrashes around wildly, and it reacts by spiking when you do things like dip the headlights or the cooling fans kicking in.

The oil pressure gauge works and registers reasonable values.

Just to mention what I would guess isn't related but just in case it is, my engine dies just after starting when cold and splutters for 30 seconds or so and needs a bit of coaxing but runs fine after that. (guessing from what I've read it's the WUR or CPR but I will put pressure gauges in and post about this in the appropriate place).

I'm going to take the instrument cluster out on sunday and inspect the connections and maybe try connecting a 9v battery to the gauges to see if they react, but any advice would be greatly appreciated. I definately don't want to be driving around without a temperature gauge.


Re: multiple instrument cluster issues - Guinney1971 - 03 Aug 2013

not sure what your problem is here, but quite a few people, including Club Technical Expert
'Richh' are at events this weekend including Carfest North, so it might be early next week before
you get a reply.

Re: multiple instrument cluster issues - jamespi - 03 Aug 2013

ok cheers

Re: multiple instrument cluster issues - RobScott - 03 Aug 2013

sounds like a bad earth matey, do you have a wiring diagram?

Re: multiple instrument cluster issues - Chris Williams - 03 Aug 2013

With the exception of the speedo not working it does sound like you may have an earth issue, but the multiplugs where they connect to the back of the cluster and the 'tracks' on the back of the cluster can also cause issues, I would try the earth first, I think it's the one located on the frame behind the drivers side wheel. This is also where the speedo drive is, could be a faulty angle drive.

Re: multiple instrument cluster issues - Rissy - 04 Aug 2013

Definitely many funnies going on there. Funnies normally means a floating reference, so yeah, make your earths are good for a start. In case you don't already have it, you'll be wanting to take a look at the circuit layout...

Re: multiple instrument cluster issues - jamespi - 04 Aug 2013

Ok, I found the earth on the chassis just behind the left horn, which was a big ball of rust. The bracket that it was bolted through that joins the radiator assembly to the chassis was a crumbly brown stick of corrosion which i didn't have the patience to try and unbolt from the radiator, but it seemed like the earth was being made through the threads of the bolt rather than the washers as that part of the chassis is coated anyway, so i replaced the very rusty bolt and sandwiched the two earthing tag rings between fresh new washers to keep them out of contact with the manky bracket.

This had no impact on my instrument issues, but I'm sure it was a good idea anyway.

I took the instrument cluster out and dismantled it completely. I cleaned up all the connectors, and tested all the tracks in the plastic circuit thingy (this thing has the production quality of sinclair zx81). I connected a 9V battery to the gauges to see if they reacted and all but the fuel gauge did. I also tested all the bulbs & holders and found two or three that needed a bit of cleaning to light up. I reconnected it all to the car and lo and behold the rpm gauge now works perfectly! (I thought I had a fast idle problem, but the gauge was just reading to high. Sits nicely at 750 now, and revs up to plausible seeming values). The temperature gauge also has now returned to the correct cold position, but i couldn't warm it up to test it as my header bottle has ruptured at the neck (see my other thread under the "engine" section).

Regarding the speedo - i haven't tried to move the car yet, but i discovered when dismantling the clocks that the trip reset stalk had disintegrated and had trapped the speedo spear under the 0 mark. When I manually spin the shaft where the angle drive attaches the speedo bobs up proportional to how hard i spin it. Given that the odometer has been going round fine, I expect the speedo to work fine now.

It seems like the only remaining problem is the fuel gauge. I noticed that someone had left marks on the back and redone the riveting so it has been opened up before. So I drilled out the rivets and had a look inside. Nothing looks wrong - except that one of the legs has a blob of solder at the top with no wire attached to it so i think one of the coils may be detached. I can't see a loose wire to reattach. I think it's beyond repair (to a mere mortal like me). To buy one from Delorean i need to buy that whole section of the cluster with the oil pressure guage too (which isnt cheap). If possible I'd like to source one of these gauges individually - they may have been used on some other cars back then. It also looks like the oil pressure, voltmeter and fuel gauge are the same unit with a different colour-coded resistor bolted across two of the legs so i could repurpose the oil pressure guage to be a fuel gauge. As it stands the fuel warning light should come on for now, but I will drain the sender to double check this when I get the chance.

Re: multiple instrument cluster issues - jamespi - 04 Aug 2013

Rissy - thanks for that wiring legend - I've never had a copy up till now so in the past I've had to deduce what a lot of the numbered components on the wiring diagram were! I am fairly familiar with the wiring diagram for a lot of the car, as almost every electrical system on her has been faulty in some way. Now that she's on the road the instrument cluster has reared its ugly head but I seem to be largely on top of it now - thanks for your help! And everyone else!

Re: multiple instrument cluster issues - Chris Williams - 05 Aug 2013

Quote:thanks for that wiring legend
I have some colour A3 laminated wiring diagrams if you want one or indeed anyone who wants one. (Just cover costs) basically the same as you can download from hear: ... ng-diagram .

That's good if the speedo now works, DMCH/Ed do a replacement trip re-set shaft kit as well now. (may be worth doing whilst the speedo is out?) Could also be worth checking out the angle drive as well as the club has ordered a batch of good replacements so if your is bust you can at least get a new one on order if you wish. viewtopic.php?f=20&t=3831

Re: multiple instrument cluster issues - jamespi - 05 Aug 2013

Does anyone have any idea if there were any other cars that used the same gauge coil units as a Delorean? I do want to have a fuel guage but I'm loathed to shell out £122 on a new cluster segment for the sake of something that like looks like it would cost about £5 to manufacture. All I need is the canister with the coil and needle in it.

Re: multiple instrument cluster issues - Rich Hanlon - 06 Aug 2013

Well, you can almost guarantee the guts of it are shared with another car as you say, and 99% it'll be a British one - so perhaps have a look at the likes of Rimmer Bros etc who cater for BL, ARG, Jag etc and see if anything looks familiar. (Lots of pics and exploded diagrams)

If you can find a manufacturers reference anywhere on it that might help the search.

Failing that, are there any decent traditional spanners-in-your-pockets scrappies on the IOW?

Re: multiple instrument cluster issues - Chris Williams - 06 Aug 2013

Quote:All I need is the canister with the coil and needle in it.

It may be worth contacting Mike (Mrdashbo) on the forum, he's had some spare cluster parts from me including a couple of the bits you require. He may have one spare he wants to move on?