Temperature Guage?????

02-02-2003, 01:44 PM

HI everyone had a quick question. When I start up my boat my temp guage jumps all the way to the right side (After about 1/2 of running it drops back down to 160 Degrees). I have a VDO guage and 2 senders (One on the T-stat housing and one on the intake manafold)....How do I tell if it is a bad guage or a bad sensor?? I'm assuming since the guage jumps to the hottest setting when the motor is Ice cold that there is a problem somewhere.....

Thanks

Chris

Vinny P · 02-02-2003, 05:40 PM

I have never heard of having 2 senders for 1 guage. I would think that there may be a feedback problem here. Try eliminating 1 sender and see what happens to the guage.

blue thunder · 02-02-2003, 07:07 PM

I had that same thing happen when I installed VDO senders with gaffrig (merc campatible) gages. The voltage reference was backwards so the readings started high and then dropped off. The second sender is probably a temperature switch for an alarm.

BT

02-03-2003, 12:59 PM

The sensor on the intake manifold is for the audio warning system. The one on the Tstat is for the guage.

Standard VDO guages use senders which operate backwards 10-180 ohms versus US standard (merc) 240 -33 ohms. To confuse things more VDO also makes guages which are backwards and work on US sensors.

You need to match the sensor to the guage. Here is a list of VDO senders. Pick the base size, probably 3/8 or 1/2 NPT and the terminal type, probably spade. I am not vouching for the online vendor either way, have never used them but they have a good list of vdo part #'s

Sender Listing Link