CALLING ALL ELECTICAL GENIUSES

davelostmissing

Senile Member
Batter is 2 year old Delco and healthy (12.8 V; 14.1 V charging).
Gauge/controller sends I believe 12v to sender which returns 5v (decreases with boost) tech support says initialization is highly sensitive to the gauge getting 5v signal when cranking.
If it uses the sender on their website it is a standard 0.5-4.5 volt analog sender, so where does the 5volt requirement come into it?(rhetorical question).
An interesting puzzle for us but a big PITA for you. I would theorize the 12v supply is dipping when you start and causing a initialize/reinitialize and the so called 5v sensing sees something a bit off. I can't think of a real easy "layman friendly" way to test this theory, powering the gauge from a regulated wall wart/ another battery?
What is the actual cranking voltage?
 

Tom Kelly

Active Member
If it uses the sender on their website it is a standard 0.5-4.5 volt analog sender, so where does the 5volt requirement come into it?(rhetorical question).
An interesting puzzle for us but a big PITA for you. I would theorize the 12v supply is dipping when you start and causing a initialize/reinitialize and the so called 5v sensing sees something a bit off. I can't think of a real easy "layman friendly" way to test this theory, powering the gauge from a regulated wall wart/ another battery?
What is the actual cranking voltage?
I am thinking that I will do two things to test this out.
1. I will measure cranking voltage first thing in the morning and then later when warm and gauge not working
2. When gauge not working I will attach another car battery via jumpers and with that car running start the car and see if gauge works.

Sound sensible?
 

Tom Kelly

Active Member
UPDATE
This morning I started the car and as usual the boost gauge initialized correctly. I drove about a mile or so until the car reached 160 degrees and went home. Re-started the car and predictably the gauge went to sender error. I hooked it up to my truck with jumper cables and got the following results.
1. Battery without bing jumped - 12.9 volts
2. Cranking voltage without being jumped - during cranking dropped to 9.9 volts and then jumped to 14.0 on start (car starts quickly)
3. Battery while being jumped - 14.2 volts
4. Cranking voltage while being jumped - during cranking dropped to 10.1 volts and then jumped to 14.1 on start.
I don't know how to interpret this. Is this normal results? If not does it indicate a battery problem or possibly the starter drawing too much amperage?
 

Tom Kelly

Active Member
UPDATE
This morning I started the car and as usual the boost gauge initialized correctly. I drove about a mile or so until the car reached 160 degrees and went home. Re-started the car and predictably the gauge went to sender error. I hooked it up to my truck with jumper cables and got the following results.
1. Battery without bing jumped - 12.9 volts
2. Cranking voltage without being jumped - during cranking dropped to 9.9 volts and then jumped to 14.0 on start (car starts quickly)
3. Battery while being jumped - 14.2 volts
4. Cranking voltage while being jumped - during cranking dropped to 10.1 volts and then jumped to 14.1 on start.
I don't know how to interpret this. Is this normal results? If not does it indicate a battery problem or possibly the starter drawing too much amperage?
I forgot to mention that the above results were pretty much the same as when I made the first start of the day and the gauge worked. Today it’s a bit cold so I tried starting just now, about an hour after warming it up, and gauge worked fine.
 

yuh8tng

New Member
Idk if this well help you but I had a electrical issue that I was chasing for almost a year. All though it’s not exactly like your issue but the similarity of the cold first start and driving does relate to the issue I had. I’m positive that you will say that it’s working fine and I also did when I was chasing my electrical issue. Long story short and I can list all kinds of stuff that I went through and fixes but at the end, it ended up being the alternator. Not the actual alternator but the regulator inside the alternator. If you can test it by installing a good alternator, new or rebuilt and see if there’s changes with your issues. Don’t take your alternator to get tested at a local parts store cus it will test good. Hopefully this suggestion will help and good luck.
 

Tom Kelly

Active Member
Idk if this well help you but I had a electrical issue that I was chasing for almost a year. All though it’s not exactly like your issue but the similarity of the cold first start and driving does relate to the issue I had. I’m positive that you will say that it’s working fine and I also did when I was chasing my electrical issue. Long story short and I can list all kinds of stuff that I went through and fixes but at the end, it ended up being the alternator. Not the actual alternator but the regulator inside the alternator. If you can test it by installing a good alternator, new or rebuilt and see if there’s changes with your issues. Don’t take your alternator to get tested at a local parts store cus it will test good. Hopefully this suggestion will help and good luck.
Thank you. Your suggestion is not far fetched. I am so desperate to fix this I have thought of replacing the alternator first and then the starter (with a mini starter) if the alternator doesn't fix it. The alternator is an easy swap. The starter I would have to bring to a shop as I don't have a lift and I am too old (or spoiled) to lay under a car again. Thanks for the suggestion . It will prompt me to try it out.
 

Tom Kelly

Active Member
Thank you. Your suggestion is not far fetched. I am so desperate to fix this I have thought of replacing the alternator first and then the starter (with a mini starter) if the alternator doesn't fix it. The alternator is an easy swap. The starter I would have to bring to a shop as I don't have a lift and I am too old (or spoiled) to lay under a car again. Thanks for the suggestion . It will prompt me to try it out.
You inspired me. I ordered up an original looking one from Kirban. I will optimistically install it when it arrives and post back.
 

Chuck Leeper

8/10's of a century!
Staff member
"during cranking dropped to 9.9 volts and then jumped to 14.0 on start".
No way that system should drop under 10 V. You aren't starting a 14 to 1 race engine.
 

Chuck Leeper

8/10's of a century!
Staff member
That would indicate an abnormal draw by the starter? Or something else?
Could be the starter.
It could be a bad ground.
It could be a corroded cable, under the insulation.
Look at the + cable, at the battery end. If there's any sign of the "green crud" there, it's very likely the corrosion is under the insulation.
You can do a volt drop test, and see what's going on.
You can also use a clamp-on amp meter, and see what the draw is.
If the grnd cable is still on the lower turbo support bolt, and is nasty/loose, that would be a source, too.
If the cables have had the original ends cut off, and the bolt on terminals are there....Game changer. Time for new cables. Those things are JUNK.
 

Tom Kelly

Active Member
Could be the starter.
It could be a bad ground.
It could be a corroded cable, under the insulation.
Look at the + cable, at the battery end. If there's any sign of the "green crud" there, it's very likely the corrosion is under the insulation.
You can do a volt drop test, and see what's going on.
You can also use a clamp-on amp meter, and see what the draw is.
If the grnd cable is still on the lower turbo support bolt, and is nasty/loose, that would be a source, too.
If the cables have had the original ends cut off, and the bolt on terminals are there....Game changer. Time for new cables. Those things are JUNK.
Cables are fairly new. I will check all grounds when I install the new alternator. Had been planning to do that anyway. Thank you for your suggestions
 

yuh8tng

New Member
Another thing to check when changing the starter is check the condition of the fusible link between the wire that goes to the starter. During my chase fort electrical gremlin the fusible link was melting and one day I wasn’t getting any crank from the starter as I was about to take off the starter when I noticed the fusible link was melted. A few days before I also noticed that the crank to start was getting weaker n weaker. I used a fusible link wire from the local parts store to fix it, to get the oem fusible link would have be to ordered online. But I also agree with everyone else on here that you should definitely make sure all power and ground wires are up to par! Another culprit I’ll mention which is known to drain power lil by lil is the fan delay relay. You can do without and it’s not really necessary Soo you can junk it. Check that there’s nuthin plugged into the green fuel pump jump wire. If something is plugged into that plug it will drain power also. Good luck and hopefully you find your culprit. If I think of anything else I will let you know. If it wasn’t for this site, other sites and the help from the GN community all over the Internet I would not be able to daily drive my 80 Mali/LC2 hybrid. In the last 3 years of daily driving I’ve had all kinds of experiences, fixes, mods and I’m never done with wanting more and upgrading.
 

Tom Kelly

Active Member
Another thing to check when changing the starter is check the condition of the fusible link between the wire that goes to the starter. During my chase fort electrical gremlin the fusible link was melting and one day I wasn’t getting any crank from the starter as I was about to take off the starter when I noticed the fusible link was melted. A few days before I also noticed that the crank to start was getting weaker n weaker. I used a fusible link wire from the local parts store to fix it, to get the oem fusible link would have be to ordered online. But I also agree with everyone else on here that you should definitely make sure all power and ground wires are up to par! Another culprit I’ll mention which is known to drain power lil by lil is the fan delay relay. You can do without and it’s not really necessary Soo you can junk it. Check that there’s nuthin plugged into the green fuel pump jump wire. If something is plugged into that plug it will drain power also. Good luck and hopefully you find your culprit. If I think of anything else I will let you know. If it wasn’t for this site, other sites and the help from the GN community all over the Internet I would not be able to daily drive my 80 Mali/LC2 hybrid. In the last 3 years of daily driving I’ve had all kinds of experiences, fixes, mods and I’m never done with wanting more and upgrading.
Thanks for the ideas. You mentioned the fan delay relay. It activates the fan at 160 degrees. Wonder if that is what triggers the problem after warm up. I’ll see if there is a problem when warm but not warm enough to trip the fan. Another lead. Thanks.
 

yuh8tng

New Member
Thanks for the ideas. You mentioned the fan delay relay. It activates the fan at 160 degrees. Wonder if that is what triggers the problem after warm up. I’ll see if there is a problem when warm but not warm enough to trip the fan. Another lead. Thanks.
the fan delay relay is one of the only relays from factory that’s not a US made and it corrodes inside. The fan delay relay is what makes the electrical fan stay on after turning off the car if it’s at high temp. when shutting down. It’s one of the worst parts installed from factory on GN’s.
 

Tom Kelly

Active Member
Hmmmm. My fan used to stay on after I turned it off when it was hot. It doesn't anymore. I thought you originally were referring to the relay that turns the fan ON at 160 and then increases the fan speed at 190. This is a different relay? If so where is it? Thanks
 

Tom Kelly

Active Member
Hmmmm. My fan used to stay on after I turned it off when it was hot. It doesn't anymore. I thought you originally were referring to the relay that turns the fan ON at 160 and then increases the fan speed at 190. This is a different relay? If so where is it? Thanks
By the way. I just turned the car on and boost gauge worked fine. Let the car reach 100 degrees. Turned off and re-started --- "Sender Error"
 

Tom Kelly

Active Member
I just checked this out on Kiran website. You may be on to something. Here is what they said about fan delay relay:

"This is the largest of the 3 relays found on the driver’s side inner fender (shown in lower right of Photo 1). Because it is affected by water and moisture, this relay can cause numerous problems… from not having the fan kick on at all when the engine is hot and off, to having the fan kick on in the middle of the night and drain the battery. It can also be the cause of a low amp volt condition and can blow the CTSY fuse."

So how can I tell if this is the problem without buying a new one ($119 at Kirban)?
 

yuh8tng

New Member
I just checked this out on Kiran website. You may be on to something. Here is what they said about fan delay relay:

"This is the largest of the 3 relays found on the driver’s side inner fender (shown in lower right of Photo 1). Because it is affected by water and moisture, this relay can cause numerous problems… from not having the fan kick on at all when the engine is hot and off, to having the fan kick on in the middle of the night and drain the battery. It can also be the cause of a low amp volt condition and can blow the CTSY fuse."

So how can I tell if this is the problem without buying a new one ($119 at Kirban)?
Disconnect and forget about it
 

Tom Kelly

Active Member
Disconnect and forget about it
We may actually be on to something. I removed the connector from the delay relay and that didn't change the results. However I checked the fan speed relays and discovered that the connector on the middle one (next to the delay relay) is trashed and not connecting properly (see picture) So disconnected all three and then connected them again (engine warm) and the gauge ran correctly. Then restarted and gauge failed again. Playing with the relays sometimes got the gauge to work so this is promising. relays.JPG
 

yuh8tng

New Member
We may actually be on to something. I removed the connector from the delay relay and that didn't change the results. However I checked the fan speed relays and discovered that the connector on the middle one (next to the delay relay) is trashed and not connecting properly (see picture) So disconnected all three and then connected them again (engine warm) and the gauge ran correctly. Then restarted and gauge failed again. Playing with the relays sometimes got the gauge to work so this is promising. View attachment 351795
I’m glad that I could help with ideas even though it might not be your culprit but definitely its something you can check off for diagnosing.
 
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