Starter Relays keep burning up

[72hemi]

I need some help. I keep frying starter relays in my 72 Challenger and I'm not sure what could be causing the problem. If I'm lucky they start the car 10 times before they fail. The car has the original harness and rallye gauges.

[734406pk]

Starter relays burning out after ten starts? That's very unusual. 72Hemi what engine do you have?

[Rich G]

I would start with a volt drop test on the positive and neg. battery cables and a starter draw test first. I would think your problem should show up there unless your getting some really cheap relays.

[1 Wild R/T]

Like I posted elsewhere...

Not saying this is your problem but just something to be aware of....

Different vehicle entirely, 92 Ford F350.... Five starter relays in a month.... All with the same failure, the starter continues to crank when you let off the key... First one I did the diagnosis & slapped a new Standard Brand part on.... Second one I went through diagnostics again & came to the conclusion it was a bad part..  But just to be on the safe side I convinced the customer we should put a starter on it... Warrantied the part & let it go.... Third relay less than a day... Went over everything with a fine tooth comb.... Same result.... Decided there must be a issue with the supplier, tried another brand.... Wanted an OE but they didn't have any in stock.. :thinking: Should be a clue but I wasn't getting it...   Used an Echlin & it didn't work out of the box.... WTH am I missing?  At my insistence the warehouse tracked down an OE part.. Out of the box it too failed..... Five bad relays? I must be crazy.... Well the man who's truck I'm working on has a second truck that's a sort of back up to the back up.... I grabbed the old original starter relay off that truck, bolted it on... And the truck has been trouble free for over four months now....

Chinese electrical component QC sucks.....

[734406pk]

Like I posted elsewhere...

Not saying this is your problem but just something to be aware of....

Different vehicle entirely, 92 Ford F350.... Five starter relays in a month.... All with the same failure, the starter continues to crank when you let off the key... First one I did the diagnosis & slapped a new Standard Brand part on.... Second one I went through diagnostics again & came to the conclusion it was a bad part..  But just to be on the safe side I convinced the customer we should put a starter on it... Warrantied the part & let it go.... Third relay less than a day... Went over everything with a fine tooth comb.... Same result.... Decided there must be a issue with the supplier, tried another brand.... Wanted an OE but they didn't have any in stock.. :thinking: Should be a clue but I wasn't getting it...   Used an Echlin & it didn't work out of the box.... WTH am I missing?  At my insistence the warehouse tracked down an OE part.. Out of the box it too failed..... Five bad relays? I must be crazy.... Well the man who's truck I'm working on has a second truck that's a sort of back up to the back up.... I grabbed the old original starter relay off that truck, bolted it on... And the truck has been trouble free for over four months now....

Chinese electrical component QC sucks.....

Jeez, what a nightmare!  Chinese QC sucks IMO.

[72hemi]

Thanks for the input. Here's an update. I pulled two of them apart, and they looked fine on the inside. So I put them back together and tried to start the car with the 3rd one that was in the car and it worked just fine. Mind you this one too did not work a few hours ago. So then I started swapping the other two I took apart in and one of them worked and the other didn't. So we took that one apart again that didn't work to see if we missed anything and nope still looks fine. So I tossed that one. At this point I am believing it has to do with the under hood temperature as it is cooled off now. I have a 340 with Doug's headers and a mini starter.

I think my next move is to thermally isolate the components and go from there.

I have tried multiple brands of relays from multiple sources, ranging in prices and they all end up with the same result.

[xtopfuel]

sounds to me like you either have a very bad connection or excessive starter draw, can you check the draw on starter?

[solarguy]

A couple of years ago, I went through 2 relays in one month.  First one stuck on powering the starter after motor started and second one wouldn't even click when turning the key.  I found an older Standard brand one on ebay, made in USA,  and it has been fine ever since. 

[734406pk]

The start relay "G" terminal grounds through the neutral safety switch (auto trans) or clutch safety switch (manual trans). The next time the relay stops working, try jumping the "G" terminal to ground (battery negative terminal) and see if the relay works then. Make sure you are in park or neutral since the safety switch is bypassed.

[72hemi]

I have that wire grounded to the body since I converted the car to a 4 speed and don't have the clutch safety switch installed. I will try grounding it to the battery and see if that helps.

[72hemi]

sounds to me like you either have a very bad connection or excessive starter draw, can you check the draw on starter?

I'll check the draw.

[734406pk]

I have that wire grounded to the body since I converted the car to a 4 speed and don't have the clutch safety switch installed. I will try grounding it to the battery and see if that helps.

Ok well that narrows it down a bit.

[dodj]

My thoughts are you have a signal problem, not a relay problem. (But make sure that wire is solidly grounded). Relay grounding is not an issue because you hard wired it to gnd. But the yellow signal wire may be intermittent on you. How about checking the connections in the bullhead connector and the connections at the steering column?

[dodj]

I'll check the draw.

Hard to do. They draw A LOT. A multimeter can't handle thecurrent and a clip on cant range fast enough.

[72hemi]

Hard to do. They draw A LOT. A multimeter can't handle thecurrent and a clip on cant range fast enough.

Well guess that's out then :-P