BillZ260 Posted February 27, 2008 Share Posted February 27, 2008 Anyone else have an electric speedo and went through this? There are almost NO posts here on E speedos. Most of the time, it flat does not work. It's getting 12V and the ground is good. I tried testing the signal wire but I don't know what I'm looking for, voltage or resistance? I didn't really notice any large changes in either measurment driving around the neighborhood but maybe my slow pace wasn't enough to make either obvious. Anyone know how to test the Halefect sending unit? When it does work, seem like it works from the point of ignition on unill I come to a complete stop the first or maybe second time. Any thoughts? Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted February 28, 2008 Author Share Posted February 28, 2008 I double checked the connections at the back of the speedometer, they are all fine. I noticed that it works after start up and reversing until I come to a complete stop. I did a bunch of googling today and didn't come up with much at all. I'll be sending AM Tech an email here in a min. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted February 28, 2008 Share Posted February 28, 2008 Bummer, I have had zero issues with mine since day one. Everything on it works flawlessly.... I don't know what to say, maybe a defective unit?? I'm using the speed sensor on the RB25det trans, which I believe to be the same as a Z32 sensor. If I remember correctly, wasn't there just two wires coming off the sensor? have you tried switching them around? I can't help.... sorry. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted February 28, 2008 Author Share Posted February 28, 2008 I have no idea why but the Autometer and Summit senders have 3 wire and most all stock senders are 2 wire. All that is documented on their install instructions, that I re-read several times. I did come across a couple of thread with simular but not the same issues and there wern't any solutions. Thanks for the input, I'll let you all know what AM says. Quote Link to comment Share on other sites More sharing options...
Mayolives Posted February 28, 2008 Share Posted February 28, 2008 Have your "programed" the spedo per Autometer's instructions? Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted February 28, 2008 Author Share Posted February 28, 2008 Yeah, I've done it a couple of times. I can tell it did something because the readings that were showing went from WAY off to just a bit off. This morning, drove the car into work and it worked for almost exactly 1 mile then just stopped. Quote Link to comment Share on other sites More sharing options...
Mayolives Posted February 28, 2008 Share Posted February 28, 2008 Autometer tech support. When all else fails, ask the ones who know. Quote Link to comment Share on other sites More sharing options...
DHale_510 Posted February 29, 2008 Share Posted February 29, 2008 I had an intermittant problem with the Autometer speedo I put in my motorhome that I chase dfor 2 years. It went away when I replaced the battery. Apparently it was more voltage sensitive than the ignition or starter. The senders are indeed Hall effect devices. Just like most electronic ignitions. They are a magnetic sensor device with very low power. I don't think you can measure anything with the sort of equipment we have in our garages. They will lose the signal easily if you have a marginal electrical connection anywhere. I like to crimp and solder just to help. I think the third connection is a ground directly between the meter and sender, again this would be to deal with the very low signal strength issues. It could also be a ggofy mechanical drive in the transmission. At least the Datsun ones were little plastic gears sensitive to being installed at the proper rotation or they would grind away. I don't recall what the T5 uses. If that gizmo isn't turning all the time, then the signal generator sees nothing and yada yada ya. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted March 1, 2008 Author Share Posted March 1, 2008 Was a nice day so I quickly suds'd down the Z and drove her around town for about an hour and a half. I noticed that the speedo is working after the first fire up, reverse then go, and stops working about .5 to 1 mile later whether I stop or not. And when it stops it just drops to 0. Nothing from the AM Tech's yet. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 2, 2008 Share Posted March 2, 2008 It's almost like somethings "timing out", which I know of nothing in the meter that would cause this .... Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted March 2, 2008 Author Share Posted March 2, 2008 It's almost like somethings "timing out", which I know of nothing in the meter that would cause this .... That's what I'm thinking. OR maybe something else is kicking IN and causing enough interferance in the signal to stop it from getting through which is apparently what some others have had issues with. Other circuits getting in the way of the 'fragile' signal. I can't think of anything that isn't already constant that is running along the signal wire under the dash, I may re-route to test... BAH!!! Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted March 2, 2008 Author Share Posted March 2, 2008 HAD to go for a quick spin today, even though it was sprinkling and I don't have my wipers on yet... Anyway, at a stoplight and was looking at the speedo sensor wire and noticed that it ran along with all the rest of the wire harness to the fuse block, and then back to the connection to the sensor. Then it dawned on me, IT PROBABLY STOPS WORKING WHEN THE FAN KICKS IN AT TEMP! So when I got home I re-routed, bypassing all the main harness wires and still no go, so I pulled out the speedo and tried having the sensor wire away from all the other wires behind the dash and BINGO! I havn't figured out where I'm goint to finish routing the wire but at least I know what the problem was. I guess any interferance is too much! Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted March 2, 2008 Share Posted March 2, 2008 Good news Bill, glad to hear you've got it solved. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted March 3, 2008 Share Posted March 3, 2008 I have heard of that problem before, Glad you solved it! Evan Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted March 6, 2008 Author Share Posted March 6, 2008 Well, after a couple more runs, the speedo is still intermittant, but works alot more than it did. I'll look into some shielding. Quote Link to comment Share on other sites More sharing options...
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