Need more electrical help, PLEASE!
Thread Starter
Team Owner
Joined: Jul 2008
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
Need more electrical help, PLEASE!
I had a problem that my blower motor wouldn't run last year, and you nice folks lead me to a blown fuse, and the fact that I had the wrong relay in my car for the "max" speed. Replacing the fuse and the relay resulted in the blower motor working correctly.
I started to drive the car this year, and noticed that the wipers wouldn't work. I found some disconnected vacuum hoses, and reconnected them, so now the wiper door is working correctly, but the wipers still won't go. I found that a bad splice on the brown (ground) wire had become disconnected, so I fixed that, but the wipers still wouldn't go. Then, I noticed that the blower motor had stopped working. I then found the fuse was blown again, and replaced it. Now, with a good fuse, and a fixed brown wiper wire, neither the wiper motor nor the blower motor are working.
I have spent more than an hour pouring over the wiring diagram trying to figure out what could be wrong, and am baffled. Any help available?
Edited to add: 1970 big block with AC.
I started to drive the car this year, and noticed that the wipers wouldn't work. I found some disconnected vacuum hoses, and reconnected them, so now the wiper door is working correctly, but the wipers still won't go. I found that a bad splice on the brown (ground) wire had become disconnected, so I fixed that, but the wipers still wouldn't go. Then, I noticed that the blower motor had stopped working. I then found the fuse was blown again, and replaced it. Now, with a good fuse, and a fixed brown wiper wire, neither the wiper motor nor the blower motor are working.
I have spent more than an hour pouring over the wiring diagram trying to figure out what could be wrong, and am baffled. Any help available?
Edited to add: 1970 big block with AC.
Last edited by Derrick Reynolds; Aug 19, 2016 at 07:27 PM.
Is my vette stock?? HAHA
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Did you bench test the wiper motor. It can be done in the car. Check Willcox's site for the video or reference material. You need to know if its the motor or the wiring.
I would check the power ar your blower motor. You may have burned a wire or melted a switch.
Then check your grounds again.
Good luck
I would check the power ar your blower motor. You may have burned a wire or melted a switch.
Then check your grounds again.
Good luck
Last edited by Rescue Rogers; Aug 20, 2016 at 07:17 AM.
Racer
Joined: Mar 2014
Posts: 316
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From: Machesney Park IL
I'll go along with RR at the moment, and check grounds. I think they both have the same grounding point. I would get a jumper wire, one to a good ground, one to metal on the wiper, and see what happens.
Team Owner
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From: Orange Park Florida
AHHH, JEEZZZZ not this common problem yet again??? there is a black ground wire from the wiper motor, the a/c blower relay and the ground/negative side of the blower motor, that was stupidly designed to be bolted to a bellhousing or starter mounting bolt, same size as the battery cable bolt....there are only TWO wires on that starter battery stud....one is a BIG one from the battery....yeh, no tschit....then the one feeding the rest of the car, which is also to the alt. output.....of course....
ANY other wire is bogus and don't belong there.....SO that wire I refer to in your OE post is probably black and belongs UP TOP connected to a bolt on the intake
3 wires to the starter.....BATTERY, Starter from ignition switch,
(small one next to block) and another one from the large BATTERY post to feed rest of the car......
IF someone still has a breaker point ign. you can have another wire to the outer side of the solenoid, away from the block.....
ANY other wire is bogus and don't belong there.....SO that wire I refer to in your OE post is probably black and belongs UP TOP connected to a bolt on the intake
3 wires to the starter.....BATTERY, Starter from ignition switch,
(small one next to block) and another one from the large BATTERY post to feed rest of the car......
IF someone still has a breaker point ign. you can have another wire to the outer side of the solenoid, away from the block.....
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Team Owner
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
Thanks guys.
'70 BB, so it is a short hood. The first thing I checked was the ground, it was bad, so I repaired it. Checked all fuses again, and the AC was blown again. replaced that, but still no joy on the wipers. Ground still checks as good.
'70 BB, so it is a short hood. The first thing I checked was the ground, it was bad, so I repaired it. Checked all fuses again, and the AC was blown again. replaced that, but still no joy on the wipers. Ground still checks as good.
Former Vendor
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Here is the schematic to chew on, later tonight I'll have some time to take a better look at this thread.
I always start at the resistor... I check for power coming into the resistor on either the yellow, green, blue or purple based on which speed you have the switch in. If I have power there then I test at the motor, if I don't have it there I go inside the car to find out why. The brown wire feeds power from the fuse panel to the switch located on the left side of the control. This switch sends power to the speed switch so I'd test there next.
I always start at the resistor... I check for power coming into the resistor on either the yellow, green, blue or purple based on which speed you have the switch in. If I have power there then I test at the motor, if I don't have it there I go inside the car to find out why. The brown wire feeds power from the fuse panel to the switch located on the left side of the control. This switch sends power to the speed switch so I'd test there next.
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From: Tampa Florida
I haven't used my wipers since the '80's and when I checked them a few months ago, they would not work. There was no battery getting to the wiper motor, it turned out to be dirty contacts at the override switch under the steering column.
I started at the wiper door safety switch, no battery, then I checked at the override switch and had battery on one side but not the other. And yes, the switch was in the correct position. Removed the switch and cleaned the contacts....problem solved.
Last edited by 71 Green 454; Aug 28, 2016 at 11:51 AM.
Thread Starter
Team Owner
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
Here is the schematic to chew on, later tonight I'll have some time to take a better look at this thread.
I always start at the resistor... I check for power coming into the resistor on either the yellow, green, blue or purple based on which speed you have the switch in. If I have power there then I test at the motor, if I don't have it there I go inside the car to find out why. The brown wire feeds power from the fuse panel to the switch located on the left side of the control. This switch sends power to the speed switch so I'd test there next.
I always start at the resistor... I check for power coming into the resistor on either the yellow, green, blue or purple based on which speed you have the switch in. If I have power there then I test at the motor, if I don't have it there I go inside the car to find out why. The brown wire feeds power from the fuse panel to the switch located on the left side of the control. This switch sends power to the speed switch so I'd test there next.
This is the schematic I used to get the blower motor working. It works fine now, but did blow another fuse, so I may have more work to be done there.
What I am working on now is the wipers. From reading older threads, you apparently have a "tutorial" on wipers? I couldn't find that on your site. Can you post a link?
Le Mans Master
Joined: Jun 2006
Posts: 6,400
Likes: 1,226
From: Tampa Florida
Thanks.
This is the schematic I used to get the blower motor working. It works fine now, but did blow another fuse, so I may have more work to be done there.
What I am working on now is the wipers. From reading older threads, you apparently have a "tutorial" on wipers? I couldn't find that on your site. Can you post a link?
This is the schematic I used to get the blower motor working. It works fine now, but did blow another fuse, so I may have more work to be done there.
What I am working on now is the wipers. From reading older threads, you apparently have a "tutorial" on wipers? I couldn't find that on your site. Can you post a link?
Thread Starter
Team Owner
Joined: Jul 2008
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
A friend of mine came over this afternoon to take a look for me. He is convinced that my ground is, in fact, bad. We were able to confirm voltage to the wiper motor, but could not confirm ground. Actually, we could not get any continuity from the engine block to the negative terminal on the battery, so we both walked away confused about how to effectively test a ground.
Is my vette stock?? HAHA
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Vettes need all sorts of grounding straps. the engine needs to be strapped to the frame. the bird cage as well. all the interior has grounds running to the bird cage.
If you have no ground from the engine to the frame run one. then check the frame to the birdcage .
to check, use a multimeter on the resistance setting. some have an audio alert when you have 0 resistance. you are looking for as close to zero as you can get. touch the 2 leads together and you get 0. running through wire will give you some resistance but very minimal.
If you have no ground from the engine to the frame run one. then check the frame to the birdcage .
to check, use a multimeter on the resistance setting. some have an audio alert when you have 0 resistance. you are looking for as close to zero as you can get. touch the 2 leads together and you get 0. running through wire will give you some resistance but very minimal.
Former Vendor
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Here is everything on wipers for your car.
http://repairs.willcoxcorvette.com/?yt=1972&s=wiper
Here is the direct PDF that deals with wipers and issues associated with the system.
http://repairs.willcoxcorvette.com/1...-72-with-test/
When you search the tech page always make sure look at the bottom for "Older Post".. it's on the second page.
Willcox
http://repairs.willcoxcorvette.com/?yt=1972&s=wiper
Here is the direct PDF that deals with wipers and issues associated with the system.
http://repairs.willcoxcorvette.com/1...-72-with-test/
When you search the tech page always make sure look at the bottom for "Older Post".. it's on the second page.
Willcox
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Team Owner
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From: In limbo
St. Jude Donor '13-'15, '17 thru '22
I'm in big trouble now!
After watching the tutorials, and studying the diagrams from Willcox, I was re-convinced the problem was with the ground since I had 12 volts at the yellow wire. So I disconnected the spliced black wire, and forced a ground there with a jumper. The wipers did not work, but worse, the whole car is dead. Nothing electrical is working. All of the fuses are OK, but no interior lights, no headlights, no starter motor, nothing.
I would say I am more than a little frustrated. Any ideas where to go next?
After watching the tutorials, and studying the diagrams from Willcox, I was re-convinced the problem was with the ground since I had 12 volts at the yellow wire. So I disconnected the spliced black wire, and forced a ground there with a jumper. The wipers did not work, but worse, the whole car is dead. Nothing electrical is working. All of the fuses are OK, but no interior lights, no headlights, no starter motor, nothing.
I would say I am more than a little frustrated. Any ideas where to go next?
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,347
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Check your fusible links. You may have fried one. Ya electrical stuff can be frustrating
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I'm in big trouble now!
After watching the tutorials, and studying the diagrams from Willcox, I was re-convinced the problem was with the ground since I had 12 volts at the yellow wire. So I disconnected the spliced black wire, and forced a ground there with a jumper. The wipers did not work, but worse, the whole car is dead. Nothing electrical is working. All of the fuses are OK, but no interior lights, no headlights, no starter motor, nothing.
I would say I am more than a little frustrated. Any ideas where to go next?
After watching the tutorials, and studying the diagrams from Willcox, I was re-convinced the problem was with the ground since I had 12 volts at the yellow wire. So I disconnected the spliced black wire, and forced a ground there with a jumper. The wipers did not work, but worse, the whole car is dead. Nothing electrical is working. All of the fuses are OK, but no interior lights, no headlights, no starter motor, nothing.
I would say I am more than a little frustrated. Any ideas where to go next?
Check the fuse links now, this is for a 72 but I think it's the same for your car.
Team Owner
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From: Crossville TN
Something in the system is creating a dead-short. And I suspect that it is in the wiper motor. When the motor was not connected, your blower motor worked. Add in the wipers and shorts abound.
Remove the connections from the wiper motor and then there should be some kind of testing that you can do between terminals on them to see if all is OK. I don't have that info, but think that testing with an ohmmeter to see what resistances you have between all combinations of the terminals should help you decide if there is a short in the motor assembly (as I suspect).
If you have blown one (or more) fusible links, you should know that you should NOT replace them with regular wire. You should find suitable fusible links to replace them. Yes, they are just smaller AWG wire...but they are inside non-flammable insulation and terminated by non-flammable end pieces. That way, if there is a short that fries the fusible link, the insulation will not catch fire.
Remove the connections from the wiper motor and then there should be some kind of testing that you can do between terminals on them to see if all is OK. I don't have that info, but think that testing with an ohmmeter to see what resistances you have between all combinations of the terminals should help you decide if there is a short in the motor assembly (as I suspect).
If you have blown one (or more) fusible links, you should know that you should NOT replace them with regular wire. You should find suitable fusible links to replace them. Yes, they are just smaller AWG wire...but they are inside non-flammable insulation and terminated by non-flammable end pieces. That way, if there is a short that fries the fusible link, the insulation will not catch fire.