Hi,

I recently acquired a 1999 Gecko RM Stretch. It has a VDO electronic tachometer that's reading a little flaky. The DIP switches on the back were set to a 6 cyl. engine setting (?) when I got it. I've changed it to a 4 cyl. engine setting (there is no 2-cyl. engine setting in the VDO instructions, which I downloaded). It's still off I'm sure. Doesn't read much over 1,000 rpm at any speed.

I have the service manual, and the schematic shows a "tach adapter" wired to both coils. Can't seem to find such a tach adapter, though I haven't taken the tank off, and would it convert 2 cyl. signal to 4 cycl. signal?

Anyone with a Gecko Stretch know? Can anyone confirm the DIP switch setting on the back of the tach?

thanks,
bill[/align]

 

Well, I wish I could help ya here, but I also have a Titan and had the same problem with mine. I was using a drag specialties tach but it also read the same...hardley moved off 1 grand.
HELP US BOTH OUT!

 

xtreme77mopar,

It seems like we're on our own on this one. Here's what I've found out so far, with a lot of research:

The tach adapter shown on the wiring diagram in the service manual is to allow the tach to see the right amount of pulses from the single fire ignition. Without it, the tach will read 1/2 the true engine speed.

I did find the tach adapter under the tank (BTW, what a PITA taking tank on andoff...), near the Battastini terminal strips. I don't know how to test it though. It looks like a small rectangular box with three wires coming out. Probably passive components as it's all potted up. For now, I'm going to assume it's OK unless I can find a test sequence for it.

I verified all my ground connections to the tach and the tach adapter. So, I'm thinking that I should get the tach tested next. (My tach works, somewhat, but it's just reading wrong. That tells me it's getting, signal, power, and ground.)
Palo Alto speedometer advertises they work on VDO tachs, so I'll send mine there.

I don't know who can check a Drag Specialties (is that the brand?), but if you can find someone to check it, that may be the next logical step after checking your connections.

I don't know if these electronic tachs are sensitive to spikes, surges, etc. Say from a jump start or something...

bill

 

Try this website
http://www.vdo.com/home/