Hey everyone, I am sick of not knowing what rpm my engine is at so I just picked up a cluster with a tach to swap over (both trucks are an 89). Is there any way to match the mileage? What wiring needs to be done for the swap? Thanks for any input you have.

I tried to search, but the search function seems to be having problems with me.

Edit: Found This so I think it'll plug right in, but I would like to change the mileage if at all possible. Anyone know about that?

 

Disassemble both clusters & put your original speedo into the tach cluster.

None. Just polish all the contacts (on the connectors & film circuit) with a pink eraser or brown paper.

While it's out, you might want to add a low fuel light. It's shown in that album.

 

Hmm, the new one has a trip meter and I'd like to have that (tracking mileage and such), is there a way to tear it down to the actual odometer and swap that?

 

No. To keep the trip odo, you'll have to either accept that odometer reading, or (if the original mileage is lower) disassemble that odometer, reset it, and reassemble it. It's not easy, and I won't post any instructions, for obvious reasons. If the original mileage is higher, you can hook up a motor to spin the new speedo until the odo gets close to the original one.

 

Thats exactly what I'l do, the new odo shows only 56000, so I get to spin through 10000 miles haha, thanks again for your help

 

New cluster works great, but the oil pressure pegs past full, that means that the gauge is shorting to ground right? It starts out at the bottom but when I start it the gauge goes past full

Edit: tried the oil gauges in the old cluster and they work, so it's soemthing with the wiring on this new cluster, all traces look fine tho

Edit 2: I tore it apart further and seperated the 2 film circuits the green one with the connectors and the copper one underneath it. I hope they're not supposed to be stuck together because they pretty much came right apart, and are quite dirty in between. Would electronic parts cleaner be safe to use to clean it all off? I would go thru and clean the connections better after, but just to clean the film themselves.

Great.....http://www.supermotors.net/registry/media/832453

 

Well I have it back together but I havn't tried it yet I traced some leads and it looks as tho the 20 ohm resistor was shorting with the copper leads, so I covered the bottom of the resistor joints with electric tape, we'll see how it goes.

Edit: Cancel that, no dice. I'm checking wire connections with my meter now. One thing I don't understand is that the pin out is different, the old gauges has the sender wire for the oil pressure on the passenger wiring harness, where the new gauges have the sender wire on the driver side harness. Here is basically my new gauges, and my old gauges have the oil wire on Pin 14 on the left plug. This is not mine, but here's the pic:
Link...Pic is big

Edit again: Just got done tracing every connection and every single connection (except for the tach wiring of course) is the exact same, except for this one wire, so I am going to just change the wire from one harness to the other. This has to work, the meter doesn't lie, and I checked and rechecked every connection. Just to make sure, would headlight resotration kits take scratches out of the lens? I was able to update the mileage (tore it all apart...10,000 miles would take roughly 11 hours with my drill at full rpms). I'd like to use my stock lens, but it doesn't have the trip meter. Last resort of course would be to drill a hole into the stock lens, but that just gives me one more thing to mess up on lol

 

Ok so I went out this morning to check the harness, and that pin is already jumpered to the other pin, so they are the same. I checked resistance between the 2 wires one more time and discovered what it is. The original gauges have the 20 ohm resistor (meter confirms), and the new gauges are completely open (no resistor). I need to cut the trace, and solder that resistor in-line, and my problem should be fixed.....right?

 

Success! I had to solder that resistor in place, rather quickly too because the film doesn't look like it could take much heat. I plan on eventually doing this, because I can see how unaccurate it is, but hey at least it's not pegged past full all the time. That would have drove me nuts!

 

So after driving it I have more problems (of course). The speedo is fine up to 35 mph when it begins to click, as I go faster, the clicking becomes more rapid, but more faint. Once I hit around 50 mph, it is also wrong. On my stock gauge, the speedo was always dead on with my gps. Now, after 50 mph, it gradually gets more and more incorrect, when I'm actually going 53 mph (gps tells me) speedo says I'm goin 50 mph. By the time I'm going 75 mph on the Speedo, I'm really going 83 mph.

I decided to try and swap my stock speedo into the new gauges but they don't swap. The speedos are just slightly different, but just enough to keep the smaller gauges (oil, gas, etc.) from fitting in. The Tach fits, but not very well either, but the smaller gauges can't even plug in. If you'd like Steve, I can PM you how I adjusted the mileage, but I very highly doubt that it had any impact on the speedo's performance.

Edit: It's AOD

 

What motor truck did the donor cluster come from?

Adrianspeeder

 

I believe it was a 351W, exact same year tho

 

Interesting about the speedo faces being different - I've never compared the '87-91s; I just assumed they'd be interchangeable like '80-86 & '92-96.

Anyway - the clicking probably isn't coming from the speedo. Pull the cable out of the sheath, disconnect the bottom end of the sheath from the trans/t-case & position it over a drain pan, wash both with carb cleaner, then grease both with PTFE. The more, the better.

 

What do you think the issue is with it being incorrect? Is the clicking causing a little more drag so it shows a little slower?

 

That's like asking if the starter is bad when you have a weak battery - you can't know about other problems until you fix the obvious one.