| Author | Message | ||
     Craig Alexander (Craig89rr) New Member Username: Craig89rr Post Number: 16 Registered: 01-2003 |
Hey guys/girls. Here are some numbers that can put your mind at ease about overheating if you have a multi meter and a few minutes. 1) Testing your gauge: 3.9L,with sending unit PRC7918: Buy 4 different � W resistors at an electronics store (20� per pack) in 18ohm, 22ohm, 83ohm, 182ohm. Also 2 ended alligator clips. Look at link photo1 and give the gauge at least 10 second to move (slow UK electronics) gauge movement per ohm resistance is : 18ohm gauge will read RED zone, 22ohm top of white, 83ohm dead center, 182 ohm bottom of white. 3.5L (PRC6317) same procedure with 25, 37, 80, 265 ohm resistors 2) Test voltage to gauge through the same single wire. Should be 10volts +/- .25V lower voltage will make gauge read higher. Higher V= lower 3) Test to see what temp ECU is getting. Look at link photo4. start rover, get to operating temp, turn rover off test ohm reading of that sensor. (ETC8496) 500-700ohms = 140 � F 300-400ohms = 176 150-200ohms = 212 4) Testing sending units PRC6317 and PRC7918 for OHM output. See link photo6: Pos lead from multi meter on sending unit ground Neg lead on Rover. These readings are for the 6317 unit but are very close to 7918. 106ohms = 160� F coolant temp 93ohms = 170 84ohms = 180 79ohms = 190 5) DIY install 2� Sunpro (mechanical) temp gauge: see links photo2,. 3 and 5 If you don�t want to splice your rad hose and are willing to use the Sunpro gauge only, They sell a 16MM fitting for the LR 3.9L and I believe the 3.5L is 5/8th which comes with the kit Links : http://members.aol.com/RRover4x4WD/photo1.jpg http://members.aol.com/RRover4x4WD/photo2.jpg http://members.aol.com/RRover4x4WD/photo3.jpg http://members.aol.com/RRover4x4WD/photo4.jpg http://members.aol.com/RRover4x4WD/photo5.jpg http://members.aol.com/RRover4x4WD/photo6.jpg | ||
| Jaco de Klerk (Biltongvreter) New Member Username: Biltongvreter Post Number: 17 Registered: 10-2002 |
Thanks Craig. Great stuff. I've printed the procedure and studied the pix. Too busy this week and away next, but will do this as soon as I'm back. Thanks again! | ||
| Jaco de Klerk (Biltongvreter) New Member Username: Biltongvreter Post Number: 18 Registered: 10-2002 |
Craig - Some progress, some idiot questions: 1. Gauge test - confirmed gauge OK. 2. V-test to gauge - V oscillating between 4V and 11V. Please confirm procedure: Disconnect sender wire from sender and connect to meter, which is grounded to vehicle. 3. ECU? Mine is a '72 model. 4. Not yet done.. right now RR doesnt want to start :-/ 5. Got VDO sender today, gauge already fitted. Need to establish best spot to fit sender, dont like rad hose as its not always filled. Jaco | ||
| Craig Alexander (Craig89rr) New Member Username: Craig89rr Post Number: 21 Registered: 01-2003 |
hey jaco, your volt test procedure is correct. being that im not that familiar with rovers past 87 dont take this as stone, but i cant imagine that your volts in the gauge bouncing around like that keeping correct temps. a stable voltage is what keeps a steady temp. i know in the 97 thru classics that there is a voltage stabilizer just for this purpose, which replacing or cleaning the contacts has fixed several eratic gauges that i know of. i know what you mean by the rad hose splice. my rover runs at around 187 and with the 190 thermostat i was wondering just how accurate my new gauge would be, but it sets right at 187. im replacing my thermostat this weekend to a 180 because im going to be drive across country and i want the extra flow, but also to keep the thermo open and have water on the sender for the new gauge all the time. my second choice was to go to a rad shop and they said they could drill and solder the fitting in for under $20 ill get back to you on the gauge voltage Craig89RR |
