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Discussion Starter #1
So I thought I had a bad speedo, as it cut out when my start button broke, and I was forced to jump it to get home. I rewired the start button the best I knew how, but while everything else works, the odometer and speedometer are still not working, even after buying a GarW unit!

See attached pictures - Did I do something wrong? This is a Billett button, and it is curious how that red wire is just chopped, but I assumed it came that way?
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Discussion Starter #2
OK, second thought, as I've been looking at the wiring diagram, and find this unlikely: Is there another point on the car I can check - let's say a few fuses that are related, etc? It's the odometer, speedometer, and tachometer...
 

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Couple quick questions to clarify . So does the start button work now ?

As far as the speedo it may be a speed sensor .I know I had a loose wire and that's all it took for it to act all weird.

Also prior to the garw install were the tach and odometer working

Sent from my Pixel 2 using Tapatalk
 

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Discussion Starter #4
Couple quick questions to clarify . So does the start button work now ?

As far as the speedo it may be a speed sensor .I know I had a loose wire and that's all it took for it to act all weird.

Also prior to the garw install were the tach and odometer working

Sent from my Pixel 2 using Tapatalk
The start button is working now, and I used the following wiring guide to wire it up:

So, on my old unit, the tach and odometer weren't working, so I sent them in for a $300 repair job, but it hasn't come back yet. (comes back today) - may have wasted that money, I guess. Doesn't matter - couldn't get the needles back to the right position, after re-soldering the leads (per another suggestion in this forum).

But here's the full skinny, as of this morning, on this situation:

I opened the door, and the GarW unit came on, after a few seconds. All the lights came on, but no display (no battery level, or tachometer, or speedometer, or odometer). I tried lights, and brake, and all these show up fine on the device.

When I closed the door, I turned on the car, and within about a minute, the GarW shutdown, and the ignition disable (security) light started blinking.

So here's what appears to be happening: The unit doesn't appear to know the car is powered on. This makes sense, since after having to jump the start button, when this all went down, I had no gauges, and the ignition disable light came on, while I was driving.

Here are some pictures:

Door open for a few seconds:
On door closed, it stays on this display, and the door open goes away.

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Engine running: (right now the red light would be blinking - you can see that the stereo has power, though...)
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There's no boot logo, or battery logo on startup, or shutdown.
 

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Discussion Starter #5 (Edited)
Update: GarW support has graciously given me some guidance, and insight on the issue. With this, I checked the following:

First I checked every fuse under the dash (as far as I know there's only 1 fuse cluster).
Then I checked every fuse under the passenger side bonnet (as far as I know there's only 1 fuse cluster).

GarW told me to check A3 for 12V, so I'm going to assume that A3 corresponds to the main white plug on the cluster, marked 3 (on the side with 1A).

With that in mind..

Here's what I checked (1 and 2 for sanity):
Pin 1: ~0v
Pin 2: ~0v
Pin 3: Fluctuates wildly between ~1v, and some other voltages in the mV range - it fluctuates so quickly, I'm unable to get a stable reading of what the true max and min are?

So I went down the 'A' side of the white plug, and only got a solid reading on the last pin, of 14V (I did this to check that my ground was solid, and that I could get a real reading from something).

So I checked continuity between the following (1 and 2 for sanity):

Pin 1: ~0 Ohms
Pin 2: ~0 Ohms
Pin 3: ~2.5 MOhms

Not a short, I guess.

Did I miss a fuse cluster?
I'm wondering if I should run a new line from ignition somewhere, to pin 3...

The fluctuating is weird. Ordinarily a wire will short, causing fuses to blow, or open, causing no voltage readings. Perhaps a partially broken wire somewhere?

Edit:
I was wrong - the B side had 12-14 on the last pins. The very end pin had 3V while off, and 12V while running. The next 3, or 4 had 12V. Now I'm reading all these with the plug in, so this may have some effect.

I also did another read on the A side with it plugged in. I just got nothing on A1-3, but I got a 1.8k ohm continuity reading.

I pulled off the entire dash to have a look at what I'm dealing with here. I don't even know where to begin.
 

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Discussion Starter #6
Knowing that this started with the engine start button, I tested one more thing, to add to my checks.
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The wire labeled "A" here is noted as a "bulb feed" wire. I would think the start engine button should be lit, whenever the acc is on. I read 0v out on A, when acc is on. I decided to check if the switch was lit by the headlights, so I turned the headlights on as well. Still read 0v.

Alright, so we can probably safely say that when I tried to bridge the leads on the start button, when the unit broke, I probably managed to bridge A to ground, or something along these lines, that does both 3A on the cluster, and A on the engine start bulb feed. Yep, dumb on my part - maybe I should have just called for a tow truck, but was stranded, and desperate.

So, that said, and with no wiring diagram, are there any thoughts as to what this might have taken out? The stereo still fires up in acc mode - thoughts? I'm tempted to run the acc line from the stereo, into that line. Maybe a bad call, depending on what happened here. If it just melted and split, as a clean break, well, I guess it would be OK. If it's bridging another wire, or something along those lines? Maybe not so much. I really wish a fuse would have blown instead...
 

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Discussion Starter #7 (Edited)
After a ton of help from Dan here, and the support at GarW, here's what I can say:

I have confirmed A3 and the illumination line on the start button have continuity. They are on the same line, which would explain this whole mess. Of course, that does not explain where the break in the line is occurring.

I remembered that as I was working on this car originally, one of the fuses was melted, under the dash (you'd think I'd remember that, but I've been messing with all this for months, on and off [mostly off]). As far as I remember, it was the interior fan. I can't know for sure, but based on this KFC wire, in the picture below (first wire on the left), I'd say it's a safe bet:

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I checked the interior fans, and they're all good. Could this be the wire that leads to A3 and the ignition illumination? Who knows? Probably? But if the fans are capable of coming on, and they were still connected to this, you'd still have voltage on those lines, but of course, there's not.

So, what to do at this point... well... I have a few options:

1. Try to splice into the interior fans line, somewhere (assuming I can find it, close to the instrument cluster), or just run a new wire, directly from that fuse panel to A3 and the starter illumination (who cares, really - if you bridge the starter, it stays on all the time anyways).

2. Splice into the radio ignition line, and run a short line to A3/starter illumination.

The difference is going to be the size of the fuse, obviously. For the interior fan line, it's a 20A fuse. For the radio, it's 7.5A.

I can't imagine the instrument cluster needing more than 7.5A, combined with the stereo.

As I discussed with Dan, I should probably chop the line at the instrument cluster, and tap in there. This way, if the wire melted somewhere, it won't short to other lines, or ground (whatever the case may be).

I'm dying to find out, but this may have to wait until I get back from a ski trip this weekend...

And not that this matters, but it appears to be line 19 O in the diagram below:
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This means it's Fused Ignition, Splice B - for whatever that's worth.
 

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Discussion Starter #8
Well, despite me testing them multiple times, support @ GarW told me to test for voltage (I was using a cheap continuity tester previously, on all the fuses) on fuse 7. Sure enough, voltage on one side, not on the other - the fuse was busted.

Everything's up and running now. I can't believe that I missed this on so many passes with the continuity tester! Anyhow - the GarW is worth the wait and price, and his willingness to help me through this was awesome support, I would never have expected.
 
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