TPS voltage adjustment

[fourbarrel]

Ok here goes.I was doing some checks on my sled ( '98 SRX with '00 electronics ) and thought I'd check the TPS to make sure the specs are still good.I used my Fluke metre and the TPS ohmed out within spec so that was good so I figured I'd do the voltage measurement too and even with the manual to go by I am apparently doing something wrong.I've only done this measurement once maybe twice and I just can't seem to get the right readings.I used 3 D cells in series and they all measured 1.54 vdc which gave me 4.69vdc when connected together.I hooked up the leads to the 2 outer terminals of the TPS and measured 4.69vdc,did the calculation of 4.69 x .136 which gave me 0.63784 vdc.So I took my + probe lead and put it on the centre terminal of the TPS to check the voltage and I'm getting 4.1 vdc at closed throttle and 1.9 vdc at WOT. Should I not be getting the 0.637 vdc at that terminal?Or adjusting the TPS to get that measurement? I don't know where I'm going off the rails here but would like someone to point me in the right direction.

 

[mrholmquist]

I think you have your batteries connected in reverse polarity. your applied voltage is 4.69 if you subtract the 4.1v you measured you are left with 0.59v . This is very close to the 0.63 volts you are expecting. if you reverse your battery you should in theory get this reading

 

[fourbarrel]

I think you have your batteries connected in reverse polarity. your applied voltage is 4.69 if you subtract the 4.1v you measured you are left with 0.59v . This is very close to the 0.63 volts you are expecting. if you reverse your battery you should in theory get this reading

If I reverse the polarity all I'll get is a negative voltage reading,but what you just stated about subtracting the measured voltage from the centre pin from the voltage of the batteries is whats lacking in the description in the service manual.That was what I did as it was the only thing that made sense and the only way to get the 0.63 volts.

 

[mrholmquist]

reverse the batteries ......put the negative
lead of your meter on the batteries negative and the positive lead of your meter on the middle terminal of the TPS and you will see it work out correctly