Code 1637 H C Please Help!!
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
Code 1637 H C Please Help!!
Back round
I just completed putting everything back together from the starter solinoid. The only issue I had was the red wire that is connected to the main post with the alt and battery, I had to solder and heat shrink that wire up top by the harness because it burned out last year. So everything checked out ok, The small red wire was a lil black but had it tested at autozone and tested on a battery and it is still reading volts, so I used it again.
I tested the battery @14.0 volts and alt was 14.4 volts with engine running.
All the other connections look fine and not bad. I do not know what else to check.
Is the ignition switch, have something to do with this? because I never checked that yet
Also do the wires on the main starter solinoid post have to be in a certain order?
All help appreciated Thanks.
I just completed putting everything back together from the starter solinoid. The only issue I had was the red wire that is connected to the main post with the alt and battery, I had to solder and heat shrink that wire up top by the harness because it burned out last year. So everything checked out ok, The small red wire was a lil black but had it tested at autozone and tested on a battery and it is still reading volts, so I used it again.
I tested the battery @14.0 volts and alt was 14.4 volts with engine running.
All the other connections look fine and not bad. I do not know what else to check.
Is the ignition switch, have something to do with this? because I never checked that yet
Also do the wires on the main starter solinoid post have to be in a certain order?
All help appreciated Thanks.
Last edited by corvet786c; May 17, 2017 at 02:54 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
The small red wire is soldered in 2 locations, would this set the code?
I just read that this is a dedicated wire where it is not spliced.
Any thoughts comments.
I need some help for this.
I just read that this is a dedicated wire where it is not spliced.
Any thoughts comments.
I need some help for this.
Last edited by corvet786c; May 17, 2017 at 05:09 PM.
Safety Car
Joined: Dec 2010
Posts: 3,938
Likes: 498
From: Fords, NJ
What your getting is DTC P1637 Generator L-Terminal Circuit
Here's a write up from another forum that explains what this does and how to trouble shoot it. All contents taken from a FSM:
http://www.gearchatter.com/viewtopic10125.php
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
As long as the solder connection is good and solid I don't see why it should matter.
What your getting is DTC P1637 Generator L-Terminal Circuit
Here's a write up from another forum that explains what this does and how to trouble shoot it. All contents taken from a FSM:
http://www.gearchatter.com/viewtopic10125.php
What your getting is DTC P1637 Generator L-Terminal Circuit
Here's a write up from another forum that explains what this does and how to trouble shoot it. All contents taken from a FSM:
http://www.gearchatter.com/viewtopic10125.php
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
OK, I just checked the 3 pin female pigtale connection from the alternator with multimeter with the key in ON position and only reading 10.4 volts,but my battery is fully charged to 12.5 volts so I guess my soldering is working, but issue is something else. Does it matter if the main wires at the starter are in a certain order(just talking about the 3 wires from batt, alt and red wire).
Would the ignition switch be the culprit? I had not checked that yet.
Need someone with electrical expertise with these cars.. Thanks Chris
Any other ideas?
Would the ignition switch be the culprit? I had not checked that yet.
Need someone with electrical expertise with these cars.. Thanks Chris
Any other ideas?
Last edited by corvet786c; May 18, 2017 at 06:17 AM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
OK, I just wiggled the starter wires on the solinoid with the key on with a wooden stick, while some one else was reading the the multimeter leads on 3 pin alt pos and did not go at all to 12 volts. Stayed around 10.5-10.2, but did not go to 12v. Is it supposed to, Could it be something else?
Wow 160 views no other responses, so where do you go if no one on here wants to help?
Wow 160 views no other responses, so where do you go if no one on here wants to help?
Last edited by corvet786c; May 18, 2017 at 08:11 AM.
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Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
C5 shop manual that I have does not show numbered pins. It does show Pins B, C, and D. (Pin A is unused) If by pin 3 you are referring to pin D, that is supposed to be battery voltage back over a red wire from the starter solenoid connection. If you do not see the same voltage as measured across the battery posts then there is a resistance in that wire or its connection that is resulting in a voltage drop. Perhaps your connections or solder job are not as good as you think they are?? Should be only wire between the alternator and the starter solenoid and that should have NO resistance end to end hence no voltage drop...........
Last edited by corvet786c; May 18, 2017 at 11:47 AM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
Looks like the small red wire is sandwiched between the batt and alt, mine is not that way. Could be the problem?
Last edited by corvet786c; May 18, 2017 at 12:24 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
OK so changing the wires around did not help, still getting 10.4 volts.
What would be the best way to test the small red wire. How to know it is bad?
This is all because GM failed to tighten the main bolt in the first place and originally the small red wire burned out. Now I have to find the resistance, what a pain.
What would be the best way to test the small red wire. How to know it is bad?
This is all because GM failed to tighten the main bolt in the first place and originally the small red wire burned out. Now I have to find the resistance, what a pain.
Last edited by corvet786c; May 18, 2017 at 04:08 PM.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
Ohm meter/digital multi meter set to the lowest number ohm setting. Disconnect the connector from the alternator and attach one of the ohm meter leads to the D pin. The other end to the eyelet on the red wire at the starter solenoid. Read meter. Needs to be ZERO ohms. I have a set of short leads with small alligator clips that I clip onto the probe from the meter and then to the object being tested so I don't need 4 hands............
Did you check to see that the connections at the battery are clean and tight??? If full battery voltage is not reaching the starter solenoid then the reading would also show low at the D pin at the alternator.
Did you check to see that the connections at the battery are clean and tight??? If full battery voltage is not reaching the starter solenoid then the reading would also show low at the D pin at the alternator.
But Yes the battery terminals are clean, what bothers me is that small red wire between alt and battery on the solinoid. I had to solder it in 2 places and tested the metal o- ring on the end and tested good.
Even before this problem I am having now, I remember last week my voltage in the DIC was getting low (12.9 13.0) even before I soldered anything.So I am wondering could it be the ignition switch or pcm. Does the ignition switch go thru terminal -D on the alternator?
So by ohming the wire, would that tell me its bad then? This is new to me.
Thanks 8VETTE7 for your help because this is really frustrating lol.
Last edited by corvet786c; May 18, 2017 at 05:18 PM.
.
Joined: Apr 2013
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From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
Doesn't have to be disconnected at both ends. One end is sufficient and that is why I suggested disconnecting the alternator connector, easy to get to. One meter probe on the D pin and the other on the ring at the starter solenoid or on the stud for the starter solenoid.
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,134
Likes: 139
From: Port St Lucie Florida
Doesn't have to be disconnected at both ends. One end is sufficient and that is why I suggested disconnecting the alternator connector, easy to get to. One meter probe on the D pin and the other on the ring at the starter solenoid or on the stud for the starter solenoid.
When I first ohmed(my setting are @ (Lowest) .200 of ohms assuming that is ZERO.
Had the wife hold the multimeter leed to the pos from alt (pin D)
while I held the other leed on the small red wire from the solinoid, nothing moved.
Then there was a very lil copper showing up top from the small red wire on the solinoid from one of the solder points it read .2, then 2nd solder point to the o-ring, read nothing. So my problem is a burned out wire from the o-ring to the first solder poing about 7 inches long.
The pin D from alt to the small copper showing read .2 which is 0 which is good.
Thanks again for your help in this I really appreciate your time.
Last edited by corvet786c; May 19, 2017 at 07:38 AM.
1st Gear
Joined: Oct 2019
Posts: 1
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Code 1637
Hello c5 enthusiasts..... I had similar code...together with charging system fault. First check your terminals n clean, at alternator..if alternator chks okay....then move on to cleaning the grounds on both sides by Fender's. Then take your battery out, n clean the ground plug on the harness.. You'll see it, these groundling plugs cause a lot of issues to various components. Then lastly check your starter connections. The bigger red battery cable sometimes... Break's at the starter solenoid connection. Due to over torque. Also check all wires as well. You van also buy ground spice connecters, 5per pack..recommend to change all three in engine bay. Eleckers corvette sells them 39.00 . .....hope this helps, this fixed my issue's.