Chrysler Repair/Electrical problem- 2000 Grand Caravan
QUESTION: 2000 Grand Caravan Sport - 3.3 engine 210K miles
I have a strange electrical problem on this mini van. The van will not start. The starter does not click and the gauges do not come on . The ignition switch, starter and cam position sensor, have been replaced and were not the culprit. This showed up 6 months ago and after 3 weeks of work. I went outside and turned the key on , and everything worked and it started and ran.
The problem has returned and now I have more info. When I turn the switch on , the gauges, flicker and go back to off . The shift quadrant illumination comes up gradually, and does not always have the square that designates the selected position. The wipers will come on and wipe and stop. If I remove the relays for the wipers (under the hood) the wipers do not come on. I suspect either a phantom ground or hot in the ignition circuit. The transmission was rebuilt some years ago and has worked fine since. The dealer said that the serial number number did not indicate a security system in the key. It does have a factory alarm system. This vehicle has also had problems with the electrical system. A battery goes bad every year and a half or so. They warranty it as a bad battery with no expense, but that may relate to the problem or be another problem.
any help you can give would be appreciated.
ANSWER: I would start by checking over the ground wires that are connected to the - post of the battery, of which there are 3. The two heavy wires go to the engine block and head, while the finer wire goes to a multi-wire splice nearby. Look closes for corrosion at the clamp-wire interface of all three, and then inspect their respective connections to the engine and the splice that I mentioned. The involvement of so many differect circuits does indeed suggest the issue is with something that is connected to the battery, and the ground wires are often overlooked as possible fault locations. Let me know what you learn.
Please 'rate' my answer (see below).
---------- FOLLOW-UP ----------
QUESTION: That was my first thought. I have already cleaned the third wire (chassis ground ) but have not removed the engine grounds. Any other thoughts?
ANSWER: Hi Robert,
The wire I would look into is the finest of the three wires on the - clamp as it is a common ground from a splice that carries ground wires for the trans controller, the powertrain controller, trans control relay, and the data link plug-in. Those are all involved in multiple issues, among which are some that have been problemmatic for you. Try shaking that splice and see if the continuity beteew the -clamp and pin 10 or 50 of the pcm, pin 50 or 57 of the tcm, or pin 85 ot the trans control relay (rear/outboard pin) are 'solid'. You did check the chassis ground, and do check the engine ground, but verify the grounded splice wire located near the battery (the thinnest - clamp wire) as described above.
Also, I am not clear about what is the issue with the wipers. The cluster gauges need fuse 2 under the dash as does the body computer so see it that fise might have a subtle crack in its wire or be corroded/loose in its socket.
Thanks for the rating/nomination which you are entitled to do again if you so choose.
---------- FOLLOW-UP ----------
QUESTION: My thinking was that the ignition switch may be getting voltage thru the wiper system because the wipers can run in the off position , when returning to the park position. The last time I ran into a phantom ground the system did crazy things because it found ground from another source . My conclusion was that this source was less positive (voltage) than the supply , thus it became negative . I seem to be losing the supply of voltage , that would be the source or the ground . Is that correct voltage flows from negative to positive?
Whoa, there is a lot of theory there. The wipers circuit doesn't run after you turn it off as an abnormality but rather a designed-in parking circuit that is inherent in the wiper motor... nothing to do with the igntion switch. So if the wipers behave normally let is take that off the table.
The electrons flow from - to +, but the 'current' is defined as the reverse of that true electron flow for convenience in circuit analysis. I doubt there are phantom grounds or less than full voltage issues here.
So do the checks that I suggested and let me know again exactly which of the issue you are having at this moment.